Commit Graph

20695 Commits

Author SHA1 Message Date
Paul E. McKenney 0f41c0ddad rcu: Provide diagnostic option to slow down grace-period scans
Grace-period scans of the rcu_node combining tree normally
proceed quite quickly, so that it is very difficult to reproduce
races against them.  This commit therefore allows grace-period
pre-initialization and cleanup to be artificially slowed down,
increasing race-reproduction probability.  A pair of pairs of new
Kconfig parameters are provided, RCU_TORTURE_TEST_SLOW_PREINIT to
enable the slowing down of propagating CPU-hotplug changes up the
combining tree along with RCU_TORTURE_TEST_SLOW_PREINIT_DELAY to
specify the delay in jiffies, and RCU_TORTURE_TEST_SLOW_CLEANUP
to enable the slowing down of the end-of-grace-period cleanup scan
along with RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY to specify the delay
in jiffies.  Boot-time parameters named rcutree.gp_preinit_delay and
rcutree.gp_cleanup_delay allow these delays to be specified at boot time.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:59:02 -07:00
Paul E. McKenney 3eaaaf6cd6 rcu: Shut up spurious gcc uninitialized-variable warning
Because gcc doesn't realize that rcu_num_lvls must be strictly greater
than zero, some versions give a spurious warning about levelcnt[0] being
uninitialized in rcu_init_one().  This commit updates the condition on
the pre-existing panic() in order to educate gcc on this point.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:59:02 -07:00
Paul E. McKenney eab128e830 rcu: Modulate grace-period slow init to normalize delay
Currently, the larger the gp_init_delay boot parameter, the slower
rcutorture will sequence through grace periods.  This commit avoids this
issue by decreasing the probability of slowing initialization of a given
grace period as the degree of slowness increases.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:59:01 -07:00
Paul Gortmaker 927da9dfd1 cpu: Remove new instance of __cpuinit that crept back in
We removed __cpuinit support (leaving no-op stubs) quite some time ago.
However a new instance was added in commit 00df35f991
("cpu: Defer smpboot kthread unparking until CPU known to scheduler")

Since we want to clobber the stubs soon, get this removed now.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:39 -07:00
Paul E. McKenney 64eaf97421 cpu: Handle smpboot_unpark_threads() uniformly
Commit 00df35f991 (cpu: Defer smpboot kthread unparking until CPU known
to scheduler) put the online path's call to smpboot_unpark_threads()
into a CPU-hotplug notifier.  This commit places the offline-failure
paths call into the same notifier for the sake of uniformity.

Note that it is not currently possible to place the offline path's call to
smpboot_park_threads() into an existing notifier because the CPU_DYING
notifiers run in a restricted environment, and the CPU_UP_PREPARE
notifiers run too soon.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:39 -07:00
Paul E. McKenney a738eec6c6 rcu: Correctly initialize ->rcu_qs_ctr_snap at online time
The rcu_data structure's ->rcu_qs_ctr_snap field is initialized at
CPU-online time from the current CPU's element of the per-CPU rcu_qs_ctr
variable.  Unfortunately, this is at CPU_UP_PREPARE time, so has nothing
to do with the CPU being onlined.  This commit therefore initializes
this variable from the incoming CPU's element of rcu_qs_ctr.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:38 -07:00
Paul E. McKenney cce7f1fc01 rcu: Remove redundant offline check
Because offline CPUs are propagated up the rcu_node tree's ->qsmaskinit
bits just before each grace period starts, the ->qsmaskinit bit cannot
be clear when the corresponding ->qsmask bit is set.  Furthermore, this
condition used to correspond to a CPU that was on its way offline, and
making RCU's notion of an offline CPU more precise has eliminated this
situation.  This commit therefore removes the now-redundant offline
check from force_qs_rnp().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:38 -07:00
Paul E. McKenney c5b5539506 rcu: Remove dead code from force_qs_rnp()
Because force_qs_rnp() is invoked only from the force-quiescent-state
code which runs only in the context of the grace-period kthread, a grace
period must always be in progress throughout force_qs_rnp()'s execution.
This commit therefore removes the rcu_gp_in_progress() check and the
associated dead code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:37 -07:00
Paul E. McKenney 0a0ba1c93f rcu: Adjust ->lock acquisition for tasks no longer migrating
Tasks are no longer migrated away from a given rcu_node structure
when all CPUs corresponding to that rcu_node structure have gone offline.
This means that rcu_read_unlock_special() no longer needs to loop
retrying rcu_node ->lock acquisition because the current task is
guaranteed to stay put.

This commit takes a small and paranoid step towards relying on this
guarantee by placing a WARN_ON_ONCE() just after the early exit from
the lock-acquisition loop.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:37 -07:00
Paul E. McKenney ea46351cea rcu: Eliminate HOTPLUG_CPU #ifdef in favor of IS_ENABLED()
This commit removes a HOTPLUG_CPU #ifdef, replacing it with
IS_ENABLED()-protected return statements.  This relies on the
optimizer to remove any resulting dead code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:37 -07:00
Nicholas Mc Guire 82072c4fcf rcu: Change function declaration to bool
rcu_cpu_has_callbacks() is declared int. The current declaration was introduced
in commit c0f4dfd4f9 (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks). But it is actually returning bool and as the function description
states " * Return true if the specified CPU has any callback....", this probably
should be a bool as all (3) call-sites currently treat it as bool.

Type-checking coccinelle spatches are being used to locate type mismatches
between function signatures and return values in this case this produced:
./kernel/rcu/tree.c:3538 WARNING: return of wrong type
                    int != bool,

Patch was compile tested with x86_64_defconfig (implies CONFIG_TREE_RCU=y)

Patch is against 4.1-rc3 (localversion-next is -next-20150511) and fixes

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:04 -07:00
Nicolas Iooss c92fb05795 rcu: Make rcu_*_data variables static
rcu_bh_data, rcu_sched_data and rcu_preempt_data are never used outside
kernel/rcu/tree.c and thus can be made static.

Doing so fixes a section mismatch warning reported by clang when
building LLVMLinux with -Wsection, because these variables were declared
in .data..percpu and defined in .data..percpu..shared_aligned since
commit 11bbb235c2 ("rcu: Use DEFINE_PER_CPU_SHARED_ALIGNED for
rcu_data").

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:03 -07:00
Paul E. McKenney 30ff1533b8 rcu: Make synchronize_sched_expedited() call wait_rcu_gp()
Currently, synchronize_sched_expedited() will call synchronize_sched()
if there is danger of counter wrap.  But if configuration says to
always do expedited grace periods, synchronize_sched() will just
call synchronize_sched_expedited() right back again.  In theory,
the old expedited operations will complete, the counters will
get back in synch, and the recursion will end.  But we could
easily run out of stack long before that time.  This commit
therefore makes synchronize_sched_expedited() invoke the underlying
wait_rcu_gp(call_rcu_sched) instead of synchronize_sched(), the same as
all the other calls out from synchronize_sched_expedited().

This bug was introduced by commit 1924bcb025 (Avoid counter wrap in
synchronize_sched_expedited()).

Reported-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:03 -07:00
Paul E. McKenney 5af4692a75 smp: Make control dependencies work on Alpha, improve documentation
The current formulation of control dependencies fails on DEC Alpha,
which does not respect dependencies of any kind unless an explicit
memory barrier is provided.  This means that the current fomulation of
control dependencies fails on Alpha.  This commit therefore creates a
READ_ONCE_CTRL() that has the same overhead on non-Alpha systems, but
causes Alpha to produce the needed ordering.  This commit also applies
READ_ONCE_CTRL() to the one known use of control dependencies.

Use of READ_ONCE_CTRL() also has the beneficial effect of adding a bit
of self-documentation to control dependencies.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-05-27 12:58:02 -07:00
Paul E. McKenney 81e701e437 rcu: Add more debug info on "kthread starved" RCU CPU stall warnings
This commit adds grace number and command-flags information to the
"kthread starved" message that is sometimes printed out as part of
RCU CPU stall warnings.  This message is caused by the corresponding
RCU grace-period kthread not having run for at least two seconds, and
this added information can be helpful when debugging.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:02 -07:00
Patrick Daly 82efed06d5 rcu: Fix missing task information during rcu-preempt stall
The first item list_for_each_entry_continue(alist) iterates over is
alist->next, rather than alist itself. Consequently,
rcu_print_detail_task_stall_rnp() skips the task referenced by gp_tasks.

Use gp_tasks->prev as the argument to list_for_each_entry_continue()
instead.

Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:02 -07:00
Joe Perches 5ce035fb7d rcu: tree_plugin: Use bool function return values of true/false not 1/0
Use the normal return values for bool functions

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:01 -07:00
Paul E. McKenney cd73ca21cd rcu: Force wakeup of rcu_gp_kthread at grace-period end
The rcu_gp_kthread_wake() refuses to do a wakeup unless at least
one of the ->gp_flags bits are set, which normally will not be the
case when the last quiescent state is reported.  This results in
up to a 3-jiffy delay given default Kconfig settings.  This commit
therefore has rcu_report_qs_rsp() set RCU_GP_FLAG_FQS before invoking
rcu_gp_kthread_wake() in order to force a more immediate wakeup at
grace-period end, thus reducing grace-period latencies.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:01 -07:00
Paul E. McKenney 3382adbc1b rcu: Eliminate a few CONFIG_RCU_NOCB_CPU_ALL #ifdefs
This commit converts several CONFIG_RCU_NOCB_CPU_ALL #ifdefs to
instead use IS_ENABLED().  This change should help avoid hiding
code from compiler diagnostics.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:00 -07:00
Paul E. McKenney 2927a689e8 rcu: Create an immutable rcu_data_p pointer to default rcu_data structure
This commit creates an immutable rcu_data_p pointer that references
rcu_preempt_data for TREE_PREEMPT_RCU builds and that references
rcu_sched_data for TREE_RCU builds.  This rcu_data_p pointer will enable
more code to move from #ifdef to IS_ENABLED().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:58:00 -07:00
Paul E. McKenney b28a7c0166 rcu: Tell the compiler that rcu_state_p is immutable
This commit adds a "const" tag to the declarations of rcu_state_p,
which should allow the compiler to generate better code and also to
catch erroneous assignments to this variable.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:57:59 -07:00
Paul E. McKenney 727b705baf rcu: Eliminate a few RCU_BOOST #ifdefs in favor of IS_ENABLED()
This commit removes a few RCU_BOOST #ifdefs, replacing them with
IS_ENABLED()-protected return statements.  This relies on the
optimizer to remove any resulting dead code.  There are several other
RCU_BOOST #ifdefs, however these rely on some per-CPU variables that
are available only under RCU_BOOST.  These might be converted later,
if the simplification proves to outweigh the increase in memory footprint.
One hoped-for advantage is more easily locating compiler errors in
obscure combinations of Kconfig parameters.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: <linux-rt-users@vger.kernel.org>
2015-05-27 12:57:59 -07:00
Paul E. McKenney e63c887cfe rcu: Convert from rcu_preempt_state to *rcu_state_p
It would be good to move more code from #ifdef to IS_ENABLED(), but
that does not work if the body of the IS_ENABLED() "if" statement
references a variable (such as rcu_preempt_state) that does not
exist if the IS_ENABLED() Kconfig variable is not set.  This commit
therefore substitutes *rcu_state_p for all uses of rcu_preempt_state
in kernel/rcu/tree_preempt.h, which should enable elimination of
a few #ifdefs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27 12:57:59 -07:00
Paul E. McKenney 7d0ae8086b rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
This commit moves from the old ACCESS_ONCE() API to the new READ_ONCE()
and WRITE_ONCE() APIs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck:  Updated to include kernel/torture.c as suggested by Jason Low. ]
2015-05-27 12:56:15 -07:00
Mark Rutland 66eb579e66 perf: allow for PMU-specific event filtering
In certain circumstances it may not be possible to schedule particular
events due to constraints other than a lack of hardware counters (e.g.
on big.LITTLE systems where CPUs support different events). The core
perf event code does not distinguish these cases and pessimistically
assumes that any failure to schedule an event means that it is not worth
attempting to schedule later events, even if some hardware counters are
still unused.

When an event a pmu cannot schedule exists in a flexible group list it
can unnecessarily prevent event groups following it in the list from
being scheduled (until it is rotated to the end of the list). This means
some events are scheduled for only a portion of the time they could be,
and for short running programs no events may be scheduled if the list is
initially sorted in an unfortunate order.

This patch adds a new (optional) filter_match function pointer to struct
pmu which a pmu driver can use to tell perf core when an event matches
pmu-specific scheduling requirements. This plugs into the existing
event_filter_match logic, and makes it possible to avoid the scheduling
problem described above. When no filter is provided by the PMU, the
existing behaviour is retained.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-05-27 16:09:58 +01:00
Steven Rostedt (Red Hat) 985e871b28 ring-buffer: Add trace_recursive checks to ring_buffer_write()
The ring_buffer_write() function isn't protected by the trace recursive
writes. Luckily, this function is not used as much and is unlikely
to ever recurse. But it should still have the protection, because
even a call to ring_buffer_lock_reserve() could cause ring buffer
corruption if called when ring_buffer_write() is being used.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-27 10:48:56 -04:00
Steven Rostedt (Red Hat) 6776221bfe ring-buffer: Allways do the trace_recursive checks
Currently the trace_recursive checks are only done if CONFIG_TRACING
is enabled. That was because there use to be a dependency with tracing
for the recursive checks (it used the task_struct trace recursive
variable). But now it uses its own variable and there is no dependency.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-27 10:44:43 -04:00
Steven Rostedt (Red Hat) 58a09ec6e3 ring-buffer: Move recursive check to per_cpu descriptor
Instead of using a global per_cpu variable to perform the recursive
checks into the ring buffer, use the already existing per_cpu descriptor
that is part of the ring buffer itself.

Not only does this simplify the code, it also allows for one ring buffer
to be used within the guts of the use of another ring buffer. For example
trace_printk() can now be used within the ring buffer to record changes
done by an instance into the main ring buffer. The recursion checks
will prevent the trace_printk() itself from causing recursive issues
with the main ring buffer (it is just ignored), but the recursive
checks wont prevent the trace_printk() from recording other ring buffers.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-27 10:42:36 -04:00
Ingo Molnar 8d12ded3dd Merge branch 'perf/urgent' into perf/core, before applying dependent patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 09:17:21 +02:00
Alexander Shishkin aa319bcd36 perf: Disallow sparse AUX allocations for non-SG PMUs in overwrite mode
PMUs that don't support hardware scatter tables require big contiguous
chunks of memory and a PMI to switch between them. However, in overwrite
using a PMI for this purpose adds extra overhead that the users would
like to avoid. Thus, in overwrite mode for such PMUs we can only allow
one contiguous chunk for the entire requested buffer.

This patch changes the behavior accordingly, so that if the buddy allocator
fails to come up with a single high-order chunk for the entire requested
buffer, the allocation will fail.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1432308626-18845-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 09:16:20 +02:00
Alexei Starovoitov dead9f29dd perf: Fix race in BPF program unregister
there is a race between perf_event_free_bpf_prog() and free_trace_kprobe():

	__free_event()
	  event->destroy(event)
	    tp_perf_event_destroy()
	      perf_trace_destroy()
		perf_trace_event_unreg()

which is dropping event->tp_event->perf_refcount and allows to proceed in:

	unregister_trace_kprobe()
	  unregister_kprobe_event()
	      trace_remove_event_call()
		    probe_remove_event_call()
	free_trace_kprobe()

while __free_event does:

	call_rcu(&event->rcu_head, free_event_rcu);
	  free_event_rcu()
	    perf_event_free_bpf_prog()

To fix the race simply move perf_event_free_bpf_prog() before
event->destroy(), since event->tp_event is still valid at that point.

Note, perf_trace_destroy() is not racing with trace_remove_event_call()
since they both grab event_mutex.

Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lizefan@huawei.com
Cc: pi3orama@163.com
Fixes: 2541517c32 ("tracing, perf: Implement BPF programs attached to kprobes")
Link: http://lkml.kernel.org/r/1431717321-28772-1-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 08:46:15 +02:00
Peter Zijlstra bed831f9a2 module, jump_label: Fix module locking
As per the module core lockdep annotations in the coming patch:

[   18.034047] ---[ end trace 9294429076a9c673 ]---
[   18.047760] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
[   18.059228]  ffffffff817d8676 ffff880036683c38 ffffffff8157e98b 0000000000000001
[   18.067541]  0000000000000000 ffff880036683c78 ffffffff8105fbc7 ffff880036683c68
[   18.075851]  ffffffffa0046b08 0000000000000000 ffffffffa0046d00 ffffffffa0046cc8
[   18.084173] Call Trace:
[   18.086906]  [<ffffffff8157e98b>] dump_stack+0x4f/0x7b
[   18.092649]  [<ffffffff8105fbc7>] warn_slowpath_common+0x97/0xe0
[   18.099361]  [<ffffffff8105fc2a>] warn_slowpath_null+0x1a/0x20
[   18.105880]  [<ffffffff810ee502>] __module_address+0x1d2/0x1e0
[   18.112400]  [<ffffffff81161153>] jump_label_module_notify+0x143/0x1e0
[   18.119710]  [<ffffffff810814bf>] notifier_call_chain+0x4f/0x70
[   18.126326]  [<ffffffff8108160e>] __blocking_notifier_call_chain+0x5e/0x90
[   18.134009]  [<ffffffff81081656>] blocking_notifier_call_chain+0x16/0x20
[   18.141490]  [<ffffffff810f0f00>] load_module+0x1b50/0x2660
[   18.147720]  [<ffffffff810f1ade>] SyS_init_module+0xce/0x100
[   18.154045]  [<ffffffff81587429>] system_call_fastpath+0x12/0x17
[   18.160748] ---[ end trace 9294429076a9c674 ]---

Jump labels is not doing it right; fix this.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jason Baron <jbaron@akamai.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27 11:09:50 +09:30
Peter Zijlstra 926a59b1df module: Annotate module version magic
Due to the new lockdep checks in the coming patch, we go:

[    9.759380] ------------[ cut here ]------------
[    9.759389] WARNING: CPU: 31 PID: 597 at ../kernel/module.c:216 each_symbol_section+0x121/0x130()
[    9.759391] Modules linked in:
[    9.759393] CPU: 31 PID: 597 Comm: modprobe Not tainted 4.0.0-rc1+ #65
[    9.759393] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
[    9.759396]  ffffffff817d8676 ffff880424567ca8 ffffffff8157e98b 0000000000000001
[    9.759398]  0000000000000000 ffff880424567ce8 ffffffff8105fbc7 ffff880424567cd8
[    9.759400]  0000000000000000 ffffffff810ec160 ffff880424567d40 0000000000000000
[    9.759400] Call Trace:
[    9.759407]  [<ffffffff8157e98b>] dump_stack+0x4f/0x7b
[    9.759410]  [<ffffffff8105fbc7>] warn_slowpath_common+0x97/0xe0
[    9.759412]  [<ffffffff810ec160>] ? section_objs+0x60/0x60
[    9.759414]  [<ffffffff8105fc2a>] warn_slowpath_null+0x1a/0x20
[    9.759415]  [<ffffffff810ed9c1>] each_symbol_section+0x121/0x130
[    9.759417]  [<ffffffff810eda01>] find_symbol+0x31/0x70
[    9.759420]  [<ffffffff810ef5bf>] load_module+0x20f/0x2660
[    9.759422]  [<ffffffff8104ef10>] ? __do_page_fault+0x190/0x4e0
[    9.759426]  [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13
[    9.759427]  [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13
[    9.759433]  [<ffffffff810ae73d>] ? trace_hardirqs_on_caller+0x11d/0x1e0
[    9.759437]  [<ffffffff812fcc0e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[    9.759439]  [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13
[    9.759441]  [<ffffffff810f1ade>] SyS_init_module+0xce/0x100
[    9.759443]  [<ffffffff81587429>] system_call_fastpath+0x12/0x17
[    9.759445] ---[ end trace 9294429076a9c644 ]---

As per the comment this site should be fine, but lets wrap it in
preempt_disable() anyhow to placate lockdep.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27 11:09:50 +09:30
Tejun Heo b5ba75b5fc cgroup: simplify threadgroup locking
Now that threadgroup locking is made global, code paths around it can
be simplified.

* lock-verify-unlock-retry dancing removed from __cgroup_procs_write().

* Race protection against de_thread() removed from
  cgroup_update_dfl_csses().

Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-26 20:35:00 -04:00
Tejun Heo d59cfc09c3 sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem
The cgroup side of threadgroup locking uses signal_struct->group_rwsem
to synchronize against threadgroup changes.  This per-process rwsem
adds small overhead to thread creation, exit and exec paths, forces
cgroup code paths to do lock-verify-unlock-retry dance in a couple
places and makes it impossible to atomically perform operations across
multiple processes.

This patch replaces signal_struct->group_rwsem with a global
percpu_rwsem cgroup_threadgroup_rwsem which is cheaper on the reader
side and contained in cgroups proper.  This patch converts one-to-one.

This does make writer side heavier and lower the granularity; however,
cgroup process migration is a fairly cold path, we do want to optimize
thread operations over it and cgroup migration operations don't take
enough time for the lower granularity to matter.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2015-05-26 20:35:00 -04:00
Tejun Heo 7d7efec368 sched, cgroup: reorganize threadgroup locking
threadgroup_change_begin/end() are used to mark the beginning and end
of threadgroup modifying operations to allow code paths which require
a threadgroup to stay stable across blocking operations to synchronize
against those sections using threadgroup_lock/unlock().

It's currently implemented as a general mechanism in sched.h using
per-signal_struct rwsem; however, this never grew non-cgroup use cases
and becomes noop if !CONFIG_CGROUPS.  It turns out that cgroups is
gonna be better served with a different sycnrhonization scheme and is
a bit silly to keep cgroups specific details as a general mechanism.

What's general here is identifying the places where threadgroups are
modified.  This patch restructures threadgroup locking so that
threadgroup_change_begin/end() become a place where subsystems which
need to sycnhronize against threadgroup changes can hook into.

cgroup_threadgroup_change_begin/end() which operate on the
per-signal_struct rwsem are created and threadgroup_lock/unlock() are
moved to cgroup.c and made static.

This is pure reorganization which doesn't cause any functional
changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2015-05-26 20:35:00 -04:00
Alexandre Belloni ac34ad27fc clockevents: Do not suspend/resume if unused
There is no point in calling suspend/resume for unused clockevents as
they are already stopped and disabled.

This is really important for AT91 as the hardware is a trainwreck and
takes ages to synchronize.

Reported-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1421399151-26800-1-git-send-email-alexandre.belloni@free-electrons.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-27 01:03:38 +02:00
Minfei Huang 26029d88ad livepatch: annotate klp_init() with __init
module_init() function should be marked __init.

[jkosina@suse.cz: remove overly verbose changelog]
Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-05-25 17:16:45 +02:00
Linus Torvalds c5db6a3bde Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "One more fix from the timer departement:

    - Handle division of negative nanosecond values proper on 32bit.

      A recent cleanup wrecked the sign handling of the dividend and
      dropped the check for negative divisors"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Fix ktime_divns to do signed division
2015-05-23 17:57:40 -07:00
David S. Miller 36583eb54d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/cadence/macb.c
	drivers/net/phy/phy.c
	include/linux/skbuff.h
	net/ipv4/tcp.c
	net/switchdev/switchdev.c

Switchdev was a case of RTNH_H_{EXTERNAL --> OFFLOAD}
renaming overlapping with net-next changes of various
sorts.

phy.c was a case of two changes, one adding a local
variable to a function whilst the second was removing
one.

tcp.c overlapped a deadlock fix with the addition of new tcp_info
statistic values.

macb.c involved the addition of two zyncq device entries.

skbuff.h involved adding back ipv4_daddr to nf_bridge_info
whilst net-next changes put two other existing members of
that struct into a union.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-23 01:22:35 -04:00
Linus Torvalds 1c8df7bd48 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "Three small fixes that have been picked up the last few weeks.
  Specifically:

   - Fix a memory corruption issue in NVMe with malignant user
     constructed request.  From Christoph.

   - Kill (now) unused blk_queue_bio(), dm was changed to not need this
     anymore.  From Mike Snitzer.

   - Always use blk_schedule_flush_plug() from the io_schedule() path
     when flushing a plug, fixing a !TASK_RUNNING warning with md.  From
     Shaohua"

* 'for-linus' of git://git.kernel.dk/linux-block:
  sched: always use blk_schedule_flush_plug in io_schedule_out
  nvme: fix kernel memory corruption with short INQUIRY buffers
  block: remove export for blk_queue_bio
2015-05-22 15:15:30 -07:00
Xunlei Pang e83d0a4106 time: Remove read_boot_clock()
Now that we have a read_boot_clock64() function available on every
architecture, and converted all the users to it, it's time to remove
the (now unused) read_boot_clock() completely from the kernel.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
[jstultz: Minor commit message tweak suggested by Ingo]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-05-22 10:36:29 -07:00
Badhri Jagan Sridharan 4e413e8526 tracing: timer: Add deferrable flag to timer_start
The timer_start event now shows whether the timer is
deferrable in case of a low-res timer. The debug_activate
function now includes a deferrable flag while calling
the trace_timer_start event.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
[jstultz: Fixed minor whitespace and grammer tweaks
 pointed out by Ingo]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-05-22 10:36:06 -07:00
John Stultz 57d05a93ad time: Rework debugging variables so they aren't global
Ingo suggested that the timekeeping debugging variables
recently added should not be global, and should be tied
to the timekeeper's read_base.

Thus this patch implements that suggestion.

This version is different from the earlier versions
as it keeps the variables in the timekeeper structure
rather then in the tkr.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-05-22 09:13:43 -07:00
Harald Geyer 6374f9124e timekeeping: Provide new API to get the current time resolution
This patch series introduces a new function
u32 ktime_get_resolution_ns(void)
which allows to clean up some driver code.

In particular the IIO subsystem has a function to provide timestamps for
events but no means to get their resolution. So currently the dht11 driver
tries to guess the resolution in a rather messy and convoluted way. We
can do much better with the new code.

This API is not designed to be exposed to user space.

This has been tested on i386, sunxi and mxs.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Harald Geyer <harald@ccbib.org>
[jstultz: Tweaked to make it build after upstream changes]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-05-22 09:12:28 -07:00
Sasha Levin 6f7d79849a time: Make sure tz_minuteswest is set to a valid value when setting time
Invalid values may overflow later, leading to undefined behaviour when
multiplied by 60 to get the amount of seconds.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-05-22 09:12:22 -07:00
Geert Uytterhoeven de8d1810fd genirq: Set IRQCHIP_SKIP_SET_WAKE for no_irq_chip
If no_irq_chip is used for wake up (e.g. gpio-keys with a simple GPIO
controller), the following warning is printed on resume from s2ram:

    WANING: CPU: 0 PID: 1046 at kernel/irq/manage.c:537 irq_set_irq_wake+0x9c/0xf8()
    Unbalanced IRQ 113 wake disable

This happens because no_irq_chip does not implement
irq_chip.irq_set_wake(), causing set_irq_wake_real() to return -ENXIO,
and irq_set_irq_wake() to reset the wake_depth to zero.

Set IRQCHIP_SKIP_SET_WAKE to indicate that irq_chip.irq_set_wake() is
not implemented.

Cfr. commit 10a50f1ab5 ("genirq: Set IRQCHIP_SKIP_SET_WAKE flag
for dummy_irq_chip").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Roger Quadros <rogerq@ti.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Link: http://lkml.kernel.org/r/1432281529-23325-1-git-send-email-geert%2Brenesas@glider.be
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-22 11:06:47 +02:00
Steven Rostedt (Red Hat) 3205f8063b ring-buffer: Add unlikelys to make fast path the default
I was running the trace_event benchmark and noticed that the times
to record a trace_event was all over the place. I looked at the assembly
of the ring_buffer_lock_reserver() and saw this:

 <ring_buffer_lock_reserve>:
       31 c0                   xor    %eax,%eax
       48 83 3d 76 47 bd 00    cmpq   $0x1,0xbd4776(%rip)        # ffffffff81d10d60 <ring_buffer_flags>
       01
       55                      push   %rbp
       48 89 e5                mov    %rsp,%rbp
       75 1d                   jne    ffffffff8113c60d <ring_buffer_lock_reserve+0x2d>
       65 ff 05 69 e3 ec 7e    incl   %gs:0x7eece369(%rip)        # a960 <__preempt_count>
       8b 47 08                mov    0x8(%rdi),%eax
       85 c0                   test   %eax,%eax
 +---- 74 12                   je     ffffffff8113c610 <ring_buffer_lock_reserve+0x30>
 |     65 ff 0d 5b e3 ec 7e    decl   %gs:0x7eece35b(%rip)        # a960 <__preempt_count>
 |     0f 84 85 00 00 00       je     ffffffff8113c690 <ring_buffer_lock_reserve+0xb0>
 |     31 c0                   xor    %eax,%eax
 |     5d                      pop    %rbp
 |     c3                      retq
 |     90                      nop
 +---> 65 44 8b 05 48 e3 ec    mov    %gs:0x7eece348(%rip),%r8d        # a960 <__preempt_count>
       7e
       41 81 e0 ff ff ff 7f    and    $0x7fffffff,%r8d
       b0 08                   mov    $0x8,%al
       65 8b 0d 58 36 ed 7e    mov    %gs:0x7eed3658(%rip),%ecx        # fc80 <current_context>
       41 f7 c0 00 ff 1f 00    test   $0x1fff00,%r8d
       74 1e                   je     ffffffff8113c64f <ring_buffer_lock_reserve+0x6f>
       41 f7 c0 00 00 10 00    test   $0x100000,%r8d
       b0 01                   mov    $0x1,%al
       75 13                   jne    ffffffff8113c64f <ring_buffer_lock_reserve+0x6f>
       41 81 e0 00 00 0f 00    and    $0xf0000,%r8d
       49 83 f8 01             cmp    $0x1,%r8
       19 c0                   sbb    %eax,%eax
       83 e0 02                and    $0x2,%eax
       83 c0 02                add    $0x2,%eax
       85 c8                   test   %ecx,%eax
       75 ab                   jne    ffffffff8113c5fe <ring_buffer_lock_reserve+0x1e>
       09 c8                   or     %ecx,%eax
       65 89 05 24 36 ed 7e    mov    %eax,%gs:0x7eed3624(%rip)        # fc80 <current_context>

The arrow is the fast path.

After adding the unlikely's, the fast path looks a bit better:

 <ring_buffer_lock_reserve>:
       31 c0                   xor    %eax,%eax
       48 83 3d 76 47 bd 00    cmpq   $0x1,0xbd4776(%rip)        # ffffffff81d10d60 <ring_buffer_flags>
       01
       55                      push   %rbp
       48 89 e5                mov    %rsp,%rbp
       75 7b                   jne    ffffffff8113c66b <ring_buffer_lock_reserve+0x8b>
       65 ff 05 69 e3 ec 7e    incl   %gs:0x7eece369(%rip)        # a960 <__preempt_count>
       8b 47 08                mov    0x8(%rdi),%eax
       85 c0                   test   %eax,%eax
       0f 85 9f 00 00 00       jne    ffffffff8113c6a1 <ring_buffer_lock_reserve+0xc1>
       65 8b 0d 57 e3 ec 7e    mov    %gs:0x7eece357(%rip),%ecx        # a960 <__preempt_count>
       81 e1 ff ff ff 7f       and    $0x7fffffff,%ecx
       b0 08                   mov    $0x8,%al
       65 8b 15 68 36 ed 7e    mov    %gs:0x7eed3668(%rip),%edx        # fc80 <current_context>
       f7 c1 00 ff 1f 00       test   $0x1fff00,%ecx
       75 50                   jne    ffffffff8113c670 <ring_buffer_lock_reserve+0x90>
       85 d0                   test   %edx,%eax
       75 7d                   jne    ffffffff8113c6a1 <ring_buffer_lock_reserve+0xc1>
       09 d0                   or     %edx,%eax
       65 89 05 53 36 ed 7e    mov    %eax,%gs:0x7eed3653(%rip)        # fc80 <current_context>
       65 8b 05 fc da ec 7e    mov    %gs:0x7eecdafc(%rip),%eax        # a130 <cpu_number>
       89 c2                   mov    %eax,%edx

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-21 17:39:29 -04:00
Lai Jiangshan 37b1ef31a5 workqueue: move flush_scheduled_work() to workqueue.h
flush_scheduled_work() is just a simple call to flush_work().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-21 17:26:22 -04:00
Lai Jiangshan 899a94fe15 workqueue: remove the lock from wq_sysfs_prep_attrs()
Reading to wq->unbound_attrs requires protection of either wq_pool_mutex
or wq->mutex, and wq_sysfs_prep_attrs() is called with wq_pool_mutex held,
so we don't need to grab wq->mutex here.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-21 17:26:22 -04:00
Lai Jiangshan da7f91b2e2 workqueue: remove the declaration of copy_workqueue_attrs()
This pre-declaration was unneeded since a previous refactor patch
6ba94429c8 ("workqueue: Reorder sysfs code").

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-21 17:26:22 -04:00
Alexei Starovoitov 04fd61ab36 bpf: allow bpf programs to tail-call other bpf programs
introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{
  ...
  bpf_tail_call(ctx, &jmp_table, index);
  ...
}
that is roughly equivalent to:
int bpf_prog(struct pt_regs *ctx)
{
  ...
  if (jmp_table[index])
    return (*jmp_table[index])(ctx);
  ...
}
The important detail that it's not a normal call, but a tail call.
The kernel stack is precious, so this helper reuses the current
stack frame and jumps into another BPF program without adding
extra call frame.
It's trivially done in interpreter and a bit trickier in JITs.
In case of x64 JIT the bigger part of generated assembler prologue
is common for all programs, so it is simply skipped while jumping.
Other JITs can do similar prologue-skipping optimization or
do stack unwind before jumping into the next program.

bpf_tail_call() arguments:
ctx - context pointer
jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table
index - index in the jump table

Since all BPF programs are idenitified by file descriptor, user space
need to populate the jmp_table with FDs of other BPF programs.
If jmp_table[index] is empty the bpf_tail_call() doesn't jump anywhere
and program execution continues as normal.

New BPF_MAP_TYPE_PROG_ARRAY map type is introduced so that user space can
populate this jmp_table array with FDs of other bpf programs.
Programs can share the same jmp_table array or use multiple jmp_tables.

The chain of tail calls can form unpredictable dynamic loops therefore
tail_call_cnt is used to limit the number of calls and currently is set to 32.

Use cases:
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

==========
- simplify complex programs by splitting them into a sequence of small programs

- dispatch routine
  For tracing and future seccomp the program may be triggered on all system
  calls, but processing of syscall arguments will be different. It's more
  efficient to implement them as:
  int syscall_entry(struct seccomp_data *ctx)
  {
     bpf_tail_call(ctx, &syscall_jmp_table, ctx->nr /* syscall number */);
     ... default: process unknown syscall ...
  }
  int sys_write_event(struct seccomp_data *ctx) {...}
  int sys_read_event(struct seccomp_data *ctx) {...}
  syscall_jmp_table[__NR_write] = sys_write_event;
  syscall_jmp_table[__NR_read] = sys_read_event;

  For networking the program may call into different parsers depending on
  packet format, like:
  int packet_parser(struct __sk_buff *skb)
  {
     ... parse L2, L3 here ...
     __u8 ipproto = load_byte(skb, ... offsetof(struct iphdr, protocol));
     bpf_tail_call(skb, &ipproto_jmp_table, ipproto);
     ... default: process unknown protocol ...
  }
  int parse_tcp(struct __sk_buff *skb) {...}
  int parse_udp(struct __sk_buff *skb) {...}
  ipproto_jmp_table[IPPROTO_TCP] = parse_tcp;
  ipproto_jmp_table[IPPROTO_UDP] = parse_udp;

- for TC use case, bpf_tail_call() allows to implement reclassify-like logic

- bpf_map_update_elem/delete calls into BPF_MAP_TYPE_PROG_ARRAY jump table
  are atomic, so user space can build chains of BPF programs on the fly

Implementation details:
=======================
- high performance of bpf_tail_call() is the goal.
  It could have been implemented without JIT changes as a wrapper on top of
  BPF_PROG_RUN() macro, but with two downsides:
  . all programs would have to pay performance penalty for this feature and
    tail call itself would be slower, since mandatory stack unwind, return,
    stack allocate would be done for every tailcall.
  . tailcall would be limited to programs running preempt_disabled, since
    generic 'void *ctx' doesn't have room for 'tail_call_cnt' and it would
    need to be either global per_cpu variable accessed by helper and by wrapper
    or global variable protected by locks.

  In this implementation x64 JIT bypasses stack unwind and jumps into the
  callee program after prologue.

- bpf_prog_array_compatible() ensures that prog_type of callee and caller
  are the same and JITed/non-JITed flag is the same, since calling JITed
  program from non-JITed is invalid, since stack frames are different.
  Similarly calling kprobe type program from socket type program is invalid.

- jump table is implemented as BPF_MAP_TYPE_PROG_ARRAY to reuse 'map'
  abstraction, its user space API and all of verifier logic.
  It's in the existing arraymap.c file, since several functions are
  shared with regular array map.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-21 17:07:59 -04:00
Luis R. Rodriguez f2411da746 driver-core: add driver module asynchronous probe support
Some init systems may wish to express the desire to have device drivers
run their probe() code asynchronously. This implements support for this
and allows userspace to request async probe as a preference through a
generic shared device driver module parameter, async_probe.

Implementation for async probe is supported through a module parameter
given that since synchronous probe has been prevalent for years some
userspace might exist which relies on the fact that the device driver
will probe synchronously and the assumption that devices it provides
will be immediately available after this.

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20 00:25:24 -07:00
Luis R. Rodriguez ecc8617053 module: add extra argument for parse_params() callback
This adds an extra argument onto parse_params() to be used
as a way to make the unused callback a bit more useful and
generic by allowing the caller to pass on a data structure
of its choice. An example use case is to allow us to easily
make module parameters for every module which we will do
next.

@ parse @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
 extern char *parse_args(const char *name,
 			 char *args,
 			 const struct kernel_param *params,
 			 unsigned num,
 			 s16 level_min,
 			 s16 level_max,
+			 void *arg,
 			 int (*unknown)(char *param, char *val,
					const char *doing
+					, void *arg
					));

@ parse_mod @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
 char *parse_args(const char *name,
 			 char *args,
 			 const struct kernel_param *params,
 			 unsigned num,
 			 s16 level_min,
 			 s16 level_max,
+			 void *arg,
 			 int (*unknown)(char *param, char *val,
					const char *doing
+					, void *arg
					))
{
	...
}

@ parse_args_found @
expression R, E1, E2, E3, E4, E5, E6;
identifier func;
@@

(
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   func);
|
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   &func);
|
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   NULL);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   func);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   &func);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   NULL);
)

@ parse_args_unused depends on parse_args_found @
identifier parse_args_found.func;
@@

int func(char *param, char *val, const char *unused
+		 , void *arg
		 )
{
	...
}

@ mod_unused depends on parse_args_found @
identifier parse_args_found.func;
expression A1, A2, A3;
@@

-	func(A1, A2, A3);
+	func(A1, A2, A3, NULL);

Generated-by: Coccinelle SmPL
Cc: cocci@systeme.lip6.fr
Cc: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20 00:25:24 -07:00
Jiri Slaby 8cdd043ab3 livepatch: introduce patch/func-walking helpers
klp_for_each_object and klp_for_each_func are now used all over the
code. One need not think what is the proper condition to check in the
for loop now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-05-19 23:58:43 +02:00
Miroslav Benes cad706df7e livepatch: make kobject in klp_object statically allocated
Make kobj variable (of type struct kobject) statically allocated in
klp_object structure. It will allow us to move in the func-object-patch
hierarchy through kobject links.

The only reason to have it dynamic was to not have empty release
callback in the code. However we have empty callbacks for function and
patch in the code now, so it is no longer valid and the advantage of
static allocation is clear.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-05-19 23:56:41 +02:00
Lai Jiangshan d4d3e25797 workqueue: ensure attrs changes are properly synchronized
Current modification to attrs via sysfs is not fully synchronized.

Process A (change cpumask)      | Process B (change numa affinity)
wq_cpumask_store()              |
  wq_sysfs_prep_attrs()         |
                                | apply_workqueue_attrs()
  apply_workqueue_attrs()       |

It results that the Process B's operation is totally reverted
without any notification, it is a buggy behavior.  So this patch
moves wq_sysfs_prep_attrs() into the protection under wq_pool_mutex
to ensure attrs changes are properly synchronized.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-19 17:37:00 -04:00
Lai Jiangshan a0111cf671 workqueue: separate out and refactor the locking of applying attrs
Applying attrs requires two locks: get_online_cpus() and wq_pool_mutex,
and this code is duplicated at two places (apply_workqueue_attrs() and
workqueue_set_unbound_cpumask()).  So we separate out this locking
code into apply_wqattrs_[un]lock() and do a minor refactor on
apply_workqueue_attrs().

The apply_wqattrs_[un]lock() will be also used on later patch for
ensuring attrs changes are properly synchronized.

tj: minor updates to comments

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-19 17:37:00 -04:00
Michal Hocko 1173ff09b9 watchdog: fix double lock in watchdog_nmi_enable_all
Commit ab992dc38f ("watchdog: Fix merge 'conflict'") has introduced an
obvious deadlock because of a typo.  watchdog_proc_mutex should be
unlocked on exit.

Thanks to Miroslav Benes who was staring at the code with me and noticed
this.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Duh-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-19 10:57:03 -07:00
Christoph Hellwig 343df3c79c suspend: simplify block I/O handling
Stop abusing struct page functionality and the swap end_io handler, and
instead add a modified version of the blk-lib.c bio_batch helpers.

Also move the block I/O code into swap.c as they are directly tied into
each other.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Ming Lin <mlin@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:19:59 -06:00
Viresh Kumar d25408756a clockevents: Stop unused clockevent devices
To avoid getting spurious interrupts on a tickless CPU, clockevent
device can now be stopped by switching to ONESHOT_STOPPED state.

The natural place for handling this transition is tick_program_event().

On 'expires == KTIME_MAX', we skip programming the event and so we need
to fix such call sites as well, to always call tick_program_event()
irrespective of the expires value.

Once the clockevent device is required again, check if it was earlier
put into ONESHOT_STOPPED state. If yes, switch its state to ONESHOT
before programming its event.

To make sure we haven't missed any corner case, add a WARN() for the
case where we try to reprogram clockevent device while we aren't
configured in ONESHOT_STOPPED state.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5146b07be7f0bc497e0ebae036590ec2fa73e540.1428031396.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 16:18:11 +02:00
Viresh Kumar 8fff52fd50 clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state
When no timers/hrtimers are pending, the expiry time is set to a
special value: 'KTIME_MAX'. This normally happens with
NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

When 'expiry == KTIME_MAX', we either cancel the 'tick-sched' hrtimer
(NOHZ_MODE_HIGHRES) or skip reprogramming clockevent device
(NOHZ_MODE_LOWRES).  But, the clockevent device is already
reprogrammed from the tick-handler for next tick.

As the clock event device is programmed in ONESHOT mode it will at
least fire one more time (unnecessarily). Timers on few
implementations (like arm_arch_timer, etc.) only support PERIODIC mode
and their drivers emulate ONESHOT over that. Which means that on these
platforms we will get spurious interrupts periodically (at last
programmed interval rate, normally tick rate).

In order to avoid spurious interrupts, the clockevent device should be
stopped or its interrupts should be masked.

A simple (yet hacky) solution to get this fixed could be: update
hrtimer_force_reprogram() to always reprogram clockevent device and
update clockevent drivers to STOP generating events (or delay it to
max time) when 'expires' is set to KTIME_MAX. But the drawback here is
that every clockevent driver has to be hacked for this particular case
and its very easy for new ones to miss this.

However, Thomas suggested to add an optional state ONESHOT_STOPPED to
solve this problem: lkml.org/lkml/2014/5/9/508.

This patch adds support for ONESHOT_STOPPED state in clockevents
core. It will only be available to drivers that implement the
state-specific callbacks instead of the legacy ->set_mode() callback.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: linaro-kernel@lists.linaro.org
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/b8b383a03ac07b13312c16850b5106b82e4245b5.1428031396.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 16:18:02 +02:00
Thomas Gleixner c3b5d3cea5 Merge branch 'linus' into timers/core
Make sure the upstream fixes are applied before adding further
modifications.
2015-05-19 16:12:32 +02:00
Thomas Gleixner a9a3f5c26a Merge branch 'irq/for-x86' into x86/apic
Pull the irq core change which is required to merge the preparatory
patches for posted interrupts.
2015-05-19 15:43:01 +02:00
Thomas Gleixner a6c761e44c Merge branch 'irq/for-x86' into irq/core
Pull in the branch which can be consumed by x86 to build their changes
on top.
2015-05-19 15:41:30 +02:00
Jiang Liu 0a4377de30 genirq: Introduce irq_set_vcpu_affinity() to target an interrupt to a VCPU
With Posted-Interrupts support in Intel CPU and IOMMU, an external
interrupt from assigned-devices could be directly delivered to a
virtual CPU in a virtual machine. Instead of hacking KVM and Intel
IOMMU drivers, we propose a platform independent interface to target
an interrupt to a specific virtual CPU in a virtual machine, or set
virtual CPU affinity for an interrupt.

By adopting this new interface and the hierarchy irqdomain, we could
easily support posted-interrupts on Intel platforms, and also provide
flexible enough interfaces for other platforms to support similar
features.

Here is the usage scenario for this interface:
Guest update MSI/MSI-X interrupt configuration
        -->QEMU and KVM handle this
        -->KVM call this interface (passing posted interrupts descriptor
           and guest vector)
        -->irq core will transfer the control to IOMMU
        -->IOMMU will do the real work of updating IRTE (IRTE has new
           format for VT-d Posted-Interrupts)

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Link: http://lkml.kernel.org/r/1432026437-16560-2-git-send-email-feng.wu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 15:41:19 +02:00
Nicholas Mc Guire ca42aaf0c8 time: Refactor msecs_to_jiffies
Refactor the msecs_to_jiffies conditional code part in time.c and 
jiffies.h putting it into conditional functions rather than #ifdefs
to improve readability.

[ tglx: Verified that there is no binary code change ]

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Joe Perches <joe@perches.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Paul Turner <pjt@google.com>
Cc: Michal Marek <mmarek@suse.cz>
Link: http://lkml.kernel.org/r/1431951554-5563-2-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 15:13:46 +02:00
Nicholas Mc Guire 0a227985d4 time: Move timeconst.h into include/generated
kernel/time/timeconst.h is moved to include/generated/ and generated 
by the top level Kbuild. This allows using timeconst.h in an earlier
build stage.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Joe Perches <joe@perches.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Paul Turner <pjt@google.com>
Cc: Michal Marek <mmarek@suse.cz>
Link: http://lkml.kernel.org/r/1431951554-5563-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 15:13:45 +02:00
Rik van Riel c1ceac6276 sched/numa: Reduce conflict between fbq_classify_rq() and migration
It is possible for fbq_classify_rq() to indicate that a CPU has tasks that
should be moved to another NUMA node, but for migrate_improves_locality
and migrate_degrades_locality to not identify those tasks.

This patch always gives preference to preferred node evaluations, and
only checks the number of faults when evaluating moves between two
non-preferred nodes on a larger NUMA system.

On a two node system, the number of faults is never evaluated. Either
a task is about to be pulled off its preferred node, or migrated onto
it.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mgorman@suse.de
Link: http://lkml.kernel.org/r/20150514225936.35b91717@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:39:19 +02:00
David Hildenbrand 8bcbde5480 sched/preempt, mm/fault: Count pagefault_disable() levels in pagefault_disabled
Until now, pagefault_disable()/pagefault_enabled() used the preempt
count to track whether in an environment with pagefaults disabled (can
be queried via in_atomic()).

This patch introduces a separate counter in task_struct to count the
level of pagefault_disable() calls. We'll keep manipulating the preempt
count to retain compatibility to existing pagefault handlers.

It is now possible to verify whether in a pagefault_disable() envionment
by calling pagefault_disabled(). In contrast to in_atomic() it will not
be influenced by preempt_enable()/preempt_disable().

This patch is based on a patch from Ingo Molnar.

Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-2-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:39:13 +02:00
Frederic Weisbecker b30f0e3ffe sched/preempt: Optimize preemption operations on __schedule() callers
__schedule() disables preemption and some of its callers
(the preempt_schedule*() family) also set PREEMPT_ACTIVE.

So we have two preempt_count() modifications that could be performed
at once.

Lets remove the preemption disablement from __schedule() and pull
this responsibility to its callers in order to optimize preempt_count()
operations in a single place.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431441711-29753-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:39:12 +02:00
Ingo Molnar a22ae71806 Linux 4.1-rc4
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJVWh3TAAoJEHm+PkMAQRiG/kwH/2c9irodp2+M9OUnX2bfsBb6
 LnChiDpvkF5BB8jhP6d/XmvPp4NJzAbTxByhjdfb2E2HkorCUHCOIn2tI1TE2pUs
 2qjkOVH+XCzoV0goGtQjzK1ht8f2IrtlDiEjyRekK5cJHzhggb22QPtWL4npyd0O
 reDmG2jsRaF9POr9uLSFEv4CEnkksmRLUU0vuQX0TZeCJ41O7TXrkN/wKrLZ5mj4
 IWpqXQaSlrffq/T5HnVbXBxk3/T8QmhrIoppiMpV1mUVj0uTqlFRNi5qwT2Nit1h
 FVljWI4+WgOk3bf7fUlp+ahopjkTgu+GuXkiRP/pdgWNQO0cxCWSAzSndAlIIAE=
 =uOoJ
 -----END PGP SIGNATURE-----

Merge tag 'v4.1-rc4' into sched/core, before applying new patches

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:37:30 +02:00
Peter Zijlstra b92b8b35a2 locking/arch: Rename set_mb() to smp_store_mb()
Since set_mb() is really about an smp_mb() -- not a IO/DMA barrier
like mb() rename it to match the recent smp_load_acquire() and
smp_store_release().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:32:00 +02:00
Rafael J. Wysocki 87e9b9f1d8 PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPEND
Since idle_should_freeze() is defined to always return 'false'
for CONFIG_SUSPEND unset, all of the code depending on it in
cpuidle_idle_call() is not necessary in that case.

Make that code depend on CONFIG_SUSPEND too to avoid building it
when it is not going to be used.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19 02:44:24 +02:00
Ruchi Kandoi 671767360d PM / sleep: Return -EBUSY from suspend_enter() on wakeup detection
If a wakeup source is found to be pending in the last stage of
suspend after syscore suspend, then the machine won't suspend, but
suspend_enter() will return 0.  That is confusing, as wakeup detection
elsewhere causes -EBUSY to be returned from suspend_enter().

To avoid the confusion, make suspend_enter() return -EBUSY in that
case too.

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-19 02:26:56 +02:00
Shaohua Li 10d784eae2 sched: always use blk_schedule_flush_plug in io_schedule_out
block plug callback could sleep, so we introduce a parameter
'from_schedule' and corresponding drivers can use it to destinguish a
schedule plug flush or a plug finish. Unfortunately io_schedule_out
still uses blk_flush_plug(). This causes below output (Note, I added a
might_sleep() in raid1_unplug to make it trigger faster, but the whole
thing doesn't matter if I add might_sleep). In raid1/10, this can cause
deadlock.

This patch makes io_schedule_out always uses blk_schedule_flush_plug.
This should only impact drivers (as far as I know, raid 1/10) which are
sensitive to the 'from_schedule' parameter.

[  370.817949] ------------[ cut here ]------------
[  370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90()
[  370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90
[  370.817971] Modules linked in: raid1
[  370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G        W       4.0.0+ #361
[  370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014
[  370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1)
[  370.817985]  ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001
[  370.817988]  ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8
[  370.817990]  ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28
[  370.817993] Call Trace:
[  370.817999]  [<ffffffff819dd7af>] dump_stack+0x4f/0x7b
[  370.818002]  [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0
[  370.818004]  [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50
[  370.818006]  [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90
[  370.818008]  [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90
[  370.818010]  [<ffffffff810776ef>] __might_sleep+0x7f/0x90
[  370.818014]  [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1]
[  370.818024]  [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0
[  370.818028]  [<ffffffff819e3550>] ? bit_wait+0x50/0x50
[  370.818031]  [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140
[  370.818033]  [<ffffffff819e3586>] bit_wait_io+0x36/0x50
[  370.818034]  [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90
[  370.818041]  [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630
[  370.818043]  [<ffffffff819e3550>] ? bit_wait+0x50/0x50
[  370.818045]  [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80
[  370.818047]  [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40
[  370.818050]  [<ffffffff811de744>] __wait_on_buffer+0x44/0x50
[  370.818053]  [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0
[  370.818058]  [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790
[  370.818062]  [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50
[  370.818064]  [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200
[  370.818066]  [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360
[  370.818068]  [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0
[  370.818070]  [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0
[  370.818072]  [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460
[  370.818074]  [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0
[  370.818076]  [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620
[  370.818079]  [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0
[  370.818081]  [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290
[  370.818085]  [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0
[  370.818088]  [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50
[  370.818094]  [<ffffffff81149691>] do_writepages+0x21/0x50
[  370.818097]  [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490
[  370.818099]  [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590
[  370.818103]  [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50
[  370.818105]  [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50
[  370.818107]  [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0
[  370.818109]  [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0
[  370.818111]  [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550
[  370.818116]  [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570
[  370.818117]  [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570
[  370.818119]  [<ffffffff8106c09b>] worker_thread+0x11b/0x470
[  370.818121]  [<ffffffff8106bf80>] ? process_one_work+0x570/0x570
[  370.818124]  [<ffffffff81071868>] kthread+0xf8/0x110
[  370.818126]  [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210
[  370.818129]  [<ffffffff819e9322>] ret_from_fork+0x42/0x70
[  370.818131]  [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210
[  370.818132] ---[ end trace 7b4deb71e68b6605 ]---

V2: don't change ->in_iowait

Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-18 16:06:41 -06:00
Thomas Gleixner 939ef66848 Merge branch 'irq/for-arm' into irq/core
Pull in the branch which can be consumed by ARM to build their changes
on top.
2015-05-18 23:59:33 +02:00
Aleksa Sarai 8ab456ac36 cgroup: switch to unsigned long for bitmasks
Switch the type of all internal cgroup masks to (unsigned long), which
is the correct type for bitmasks. This is in preparation for the
for_each_subsys_which patch.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-18 17:57:52 -04:00
Lai Jiangshan f7142ed483 workqueue: simplify wq_update_unbound_numa()
wq_update_unbound_numa() is known be called with wq_pool_mutex held.

But wq_update_unbound_numa() requests wq->mutex before reading
wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq.  But these fields
were changed to be allowed being read with wq_pool_mutex held.  So we
simply remove the mutex_lock(&wq->mutex).

Without the dependence on the the mutex_lock(&wq->mutex), the test
of wq->unbound_attrs->no_numa can also be moved upward.

The old code need a long comment to describe the stableness of
@wq->unbound_attrs which is also guaranteed by wq_pool_mutex now,
so we don't need this such comment.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-18 16:22:57 -04:00
Lai Jiangshan 5b95e1af8d workqueue: wq_pool_mutex protects the attrs-installation
Current wq_pool_mutex doesn't proctect the attrs-installation, it results
that ->unbound_attrs, ->numa_pwq_tbl[] and ->dfl_pwq can only be accessed
under wq->mutex and causes some inconveniences. Example, wq_update_unbound_numa()
has to acquire wq->mutex before fetching the wq->unbound_attrs->no_numa
and the old_pwq.

attrs-installation is a short operation, so this change will no cause any
latency for other operations which also acquire the wq_pool_mutex.

The only unprotected attrs-installation code is in apply_workqueue_attrs(),
so this patch touches code less than comments.

It is also a preparation patch for next several patches which read
wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq with
only wq_pool_mutex held.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-18 16:22:56 -04:00
Peter Zijlstra ab992dc38f watchdog: Fix merge 'conflict'
Two watchdog changes that came through different trees had a non
conflicting conflict, that is, one changed the semantics of a variable
but no actual code conflict happened. So the merge appeared fine, but
the resulting code did not behave as expected.

Commit 195daf665a ("watchdog: enable the new user interface of the
watchdog mechanism") changes the semantics of watchdog_user_enabled,
which thereafter is only used by the functions introduced by
b3738d2932 ("watchdog: Add watchdog enable/disable all functions").

There further appears to be a distinct lack of serialization between
setting and using watchdog_enabled, so perhaps we should wrap the
{en,dis}able_all() things in watchdog_proc_mutex.

This patch fixes a s2r failure reported by Michal; which I cannot
readily explain. But this does make the code internally consistent
again.

Reported-and-tested-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-18 10:08:29 -07:00
Stefan Agner c5863484c1 genirq: generic chip: Support hierarchy domain
Use the new helper function irq_domain_set_info to make sure the
function irq_domain_set_hwirq_and_chip is being called, which is
crucial to save irqdomain specific data to irq_data.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: marc.zyngier@arm.com
Cc: linux@arm.linux.org.uk
Cc: u.kleine-koenig@pengutronix.de
Cc: olof@lixom.net
Cc: arnd@arndb.de
Cc: daniel.lezcano@linaro.org
Cc: mark.rutland@arm.com
Cc: pawel.moll@arm.com
Cc: robh+dt@kernel.org
Cc: ijc+devicetree@hellion.org.uk
Cc: galak@codeaurora.org
Cc: mcoquelin.stm32@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: shawn.guo@linaro.org
Cc: kernel@pengutronix.de
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/1431769465-26867-4-git-send-email-stefan@agner.ch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18 17:32:44 +02:00
Stefan Agner 3cfeffc265 genirq: Add irq_chip_(enable/disable)_parent
Add helper irq_chip_enable_parent and irq_chip_disable_parent. The
helper implement the default behavior in case irq_enable or irq_disable
is not implemented for the parent interrupt chip, which is calling the
irq_mask or irq_unmask respectively.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: marc.zyngier@arm.com
Cc: linux@arm.linux.org.uk
Cc: u.kleine-koenig@pengutronix.de
Cc: olof@lixom.net
Cc: arnd@arndb.de
Cc: daniel.lezcano@linaro.org
Cc: mark.rutland@arm.com
Cc: pawel.moll@arm.com
Cc: robh+dt@kernel.org
Cc: ijc+devicetree@hellion.org.uk
Cc: galak@codeaurora.org
Cc: mcoquelin.stm32@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: shawn.guo@linaro.org
Cc: kernel@pengutronix.de
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/1431769465-26867-3-git-send-email-stefan@agner.ch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18 17:32:44 +02:00
Stefan Agner 5f22f5c668 irqdomain: Add non-hierarchy helper irq_domain_set_info
This adds the helper irq_domain_set_info() in a non-domain hierarchy
variant. This allows to use the helper for generic chip since not
all chips using generic chip support domain hierarchy.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: marc.zyngier@arm.com
Cc: linux@arm.linux.org.uk
Cc: u.kleine-koenig@pengutronix.de
Cc: olof@lixom.net
Cc: arnd@arndb.de
Cc: daniel.lezcano@linaro.org
Cc: mark.rutland@arm.com
Cc: pawel.moll@arm.com
Cc: robh+dt@kernel.org
Cc: ijc+devicetree@hellion.org.uk
Cc: galak@codeaurora.org
Cc: mcoquelin.stm32@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: shawn.guo@linaro.org
Cc: kernel@pengutronix.de
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/1431769465-26867-2-git-send-email-stefan@agner.ch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18 17:32:43 +02:00
NeilBrown 3c646f2c6a genirq: Don't suspend nested_thread irqs over system suspend
Nested IRQs can only fire when the parent irq fires.  So when the
parent is suspended, there is no need to suspend the child irq.

Suspending nested irqs can cause a problem is they are suspended or
resumed in the wrong order.  If an interrupt fires while the parent is
active but the child is suspended, then the interrupt will not be
acknowledged properly and so an interrupt storm can result.  This is
particularly likely if the parent is resumed before the child, and the
interrupt was raised during suspend.

Ensuring correct ordering would be possible, but it is simpler to just
never suspend nested interrupts.

Signed-off-by: NeilBrown <neil@brown.name>
Cc: GTA04 owners <gta04-owner@goldelico.com>
Cc: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/20150517151934.2393e8f8@notabene.brown
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18 17:23:47 +02:00
Peter Zijlstra 4cfafd3082 sched,perf: Fix periodic timers
In the below two commits (see Fixes) we have periodic timers that can
stop themselves when they're no longer required, but need to be
(re)-started when their idle condition changes.

Further complications is that we want the timer handler to always do
the forward such that it will always correctly deal with the overruns,
and we do not want to race such that the handler has already decided
to stop, but the (external) restart sees the timer still active and we
end up with a 'lost' timer.

The problem with the current code is that the re-start can come before
the callback does the forward, at which point the forward from the
callback will WARN about forwarding an enqueued timer.

Now, conceptually its easy to detect if you're before or after the fwd
by comparing the expiration time against the current time. Of course,
that's expensive (and racy) because we don't have the current time.

Alternatively one could cache this state inside the timer, but then
everybody pays the overhead of maintaining this extra state, and that
is undesired.

The only other option that I could see is the external timer_active
variable, which I tried to kill before. I would love a nicer interface
for this seemingly simple 'problem' but alas.

Fixes: 272325c482 ("perf: Fix mux_interval hrtimer wreckage")
Fixes: 77a4d1a1b9 ("sched: Cleanup bandwidth timers")
Cc: pjt@google.com
Cc: tglx@linutronix.de
Cc: klamm@yandex-team.ru
Cc: mingo@kernel.org
Cc: bsegall@google.com
Cc: hpa@zytor.com
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150514102311.GX21418@twins.programming.kicks-ass.net
2015-05-18 17:17:42 +02:00
Minfei Huang 36e505c16e livepatch: Prevent patch inconsistencies if the coming module notifier fails
The previous patches can be applied, once the corresponding module is
loaded. In general, the patch will do relocation (if necessary) and
obtain/verify function address before we start to enable patch.

There are three different situations in which the coming module notifier
can fail:

1) relocations are not applied for some reason. In this case kallsyms
for module symbol is not called at all. The patch is not applied to the
module. If the user disable and enable patch again, there is possible
bug in klp_enable_func. If the user specified func->old_addr for some
function in the module (and he shouldn't do that, but nevertheless) our
warning would not catch it, ftrace will reject to register the handler
because of wrong address or will register the handler for wrong address.

2) relocations are applied successfully, but kallsyms lookup fails. In
this case func->old_addr can be correct for all previous lookups, 0 for
current failed one, and "unspecified" for the rest. If we undergo the
same scenario as in 1, the behaviour differs for three cases, but the
patch is not enabled anyway.

3) the object is initialized, but klp_enable_object fails in the
notifier due to possible ftrace error. Since it is improbable that
ftrace would heal itself in the future, we would get those errors
everytime the patch is enabled.

In order to fix above situations, we can make obj->mod to NULL, if the
coming modified notifier fails.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-05-18 11:08:44 +02:00
Nicholas Mc Guire 58ac93e4f2 sched: Fix function declaration return type mismatch
static code checking was unhappy with:

  ./kernel/sched/fair.c:162 WARNING: return of wrong type
                int != unsigned int

get_update_sysctl_factor() is declared to return int but is
currently  returning an unsigned int. The first few preprocessed
lines are:

 static int get_update_sysctl_factor(void)
 {
 unsigned int cpus = ({ int __min1 = (cpumask_weight(cpu_online_mask));
 int __min2 = (8); __min1 < __min2 ? __min1: __min2; });
 unsigned int factor;

The type used by min_t() should be 'unsigned int' and the return type
of get_update_sysctl_factor() should also be 'unsigned int' as its
call-site update_sysctl() is expecting 'unsigned int' and the values
utilizing:

  'factor'
  'sysctl_sched_min_granularity'
  'sched_nr_latency'
  'sysctl_sched_wakeup_granularity'

... are also all 'unsigned int', plus cpumask_weight() is also
returning 'unsigned int'.

So the natural type to use around here is 'unsigned int'.

( Patch was compile tested with x86_64_defconfig +
  CONFIG_SCHED_DEBUG=y and the changed sections in
  kernel/sched/fair.i were reviewed. )

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
[ Improved the changelog a bit. ]
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431716742-11077-1-git-send-email-hofrat@osadl.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-17 06:47:46 +02:00
Linus Torvalds 14db1e8dc0 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Two fixes: a suspend/resume related regression fix, and an RT priority
  boosting fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Fix regression in cpuset_cpu_inactive() for suspend
  sched: Handle priority boosted tasks proper in setscheduler()
2015-05-15 12:42:33 -07:00
Linus Torvalds ef4a293a44 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also a lockdep annotation fix, a PMU event
  list fix and a new model addition"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/liblockdep: Fix compilation error
  tools/liblockdep: Fix linker error in case of cross compile
  perf tools: Use getconf to determine number of online CPUs
  tools: Fix tools/vm build
  perf/x86/rapl: Enable Broadwell-U RAPL support
  perf/x86/intel: Fix SLM cache event list
  perf: Annotate inherited event ctx->mutex recursion
2015-05-15 12:38:21 -07:00
Rafael J. Wysocki 75e0678e70 PM / tick: Add tracepoints for suspend-to-idle diagnostics
Add suspend/resume tracepoints to tick_freeze() and tick_unfreeze()
to catch when timekeeping is suspended and resumed during suspend-to-idle
so as to be able to check whether or not we enter the "frozen" state
and to measure the time spent in it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-15 00:26:06 +02:00
Rafael J. Wysocki 827a5aefc5 sched / idle: Call default_idle_call() from cpuidle_enter_state()
The check of the cpuidle_enter() return value against -EBUSY
made in call_cpuidle() will not be necessary any more if
cpuidle_enter_state() calls default_idle_call() directly when it
is about to return -EBUSY, so make that happen and eliminate the
check.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-14 21:37:47 +02:00
Rafael J. Wysocki faad384928 sched / idle: Call idle_set_state() from cpuidle_enter_state()
Introduce a wrapper function around idle_set_state() called
sched_idle_set_state() that will pass this_rq() to it as the
first argument and make cpuidle_enter_state() call the new
function before and after entering the target state.

At the same time, remove direct invocations of idle_set_state()
from call_cpuidle().

This will allow the invocation of default_idle_call() to be
moved from call_cpuidle() to cpuidle_enter_state() safely
and call_cpuidle() to be simplified a bit as a result.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-14 21:35:10 +02:00
Steven Rostedt (Red Hat) a723776573 tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_raw_##call structures are built
by macros for trace events. They have nothing to do with function tracing.
Rename them.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 21:48:40 -04:00
Thomas Gleixner 6ce47fd961 rtmutex: Warn if trylock is called from hard/softirq context
rt_mutex_trylock() must be called from thread context. It can be
called from atomic regions (preemption or interrupts disabled), but
not from hard/softirq/nmi context. Add a warning to alert abusers.

The reasons for this are:

    1) There is a potential deadlock in the slowpath

    2) Another cpu which blocks on the rtmutex will boost the task
       which allegedly locked the rtmutex, but that cannot work
       because the hard/softirq context borrows the task context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
2015-05-13 22:49:12 +02:00
Steven Rostedt (Red Hat) 09a5059aa1 tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled()
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_trigger_soft_disabled() tests if a
trace_event is soft disabled (called but not traced), and returns true if
it is. It has nothing to do with function tracing and should be renamed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 15:25:39 -04:00
Steven Rostedt (Red Hat) 5d6ad960a7 tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_*
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The FTRACE_EVENT_FL_* flags are flags to
do with the trace_event files in the tracefs directory. They are not related
to function tracing. Rename them to a more descriptive name.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 15:24:57 -04:00
Steven Rostedt (Red Hat) 7967b3e0c4 tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dir
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structure ftrace_subsystem_dir holds
the information about trace event subsystems. It should not be named
ftrace, rename it to trace_subsystem_dir.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:59:40 -04:00
David S. Miller b04096ff33 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Four minor merge conflicts:

1) qca_spi.c renamed the local variable used for the SPI device
   from spi_device to spi, meanwhile the spi_set_drvdata() call
   got moved further up in the probe function.

2) Two changes were both adding new members to codel params
   structure, and thus we had overlapping changes to the
   initializer function.

3) 'net' was making a fix to sk_release_kernel() which is
   completely removed in 'net-next'.

4) In net_namespace.c, the rtnl_net_fill() call for GET operations
   had the command value fixed, meanwhile 'net-next' adjusted the
   argument signature a bit.

This also matches example merge resolutions posted by Stephen
Rothwell over the past two days.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-13 14:31:43 -04:00
Steven Rostedt (Red Hat) 687fcc4aee tracing: Rename ftrace_event_name() to trace_event_name()
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. ftrace_event_name() returns the name of
an event tracepoint, has nothing to do with function tracing. Rename it
to trace_event_name().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:20:14 -04:00
Steven Rostedt (Red Hat) 609a740452 tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAX
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. Rename the max trace_event type size to
something more descriptive and appropriate.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:06:42 -04:00
Steven Rostedt (Red Hat) 892c505aac tracing: Rename ftrace_output functions to trace_output
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_output_*() and ftrace_raw_output_*()
functions represent the trace_event code. Rename them to just trace_output
or trace_raw_output.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:06:41 -04:00
Steven Rostedt (Red Hat) 3f795dcfc7 tracing: Rename ftrace_event_buffer to trace_event_buffer.
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_event_buffer functions and data
structures are for trace_events and not for function hooks. Rename them
to trace_event_buffer*.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:06:36 -04:00
Steven Rostedt (Red Hat) 2425bcb924 tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structures ftrace_event_call and
ftrace_event_class have nothing to do with the function hooks, and are
really trace_event structures. Rename ftrace_event_* to trace_event_*.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:06:10 -04:00
Steven Rostedt (Red Hat) 7f1d2f8210 tracing: Rename ftrace_event_file to trace_event_file
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structure ftrace_event_file is really
about trace events and not "ftrace". Rename it to trace_event_file.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:05:16 -04:00
Steven Rostedt (Red Hat) 9023c93090 tracing: Rename (un)register_ftrace_event() to (un)register_trace_event()
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The functions (un)register_ftrace_event() is
really about trace_events, and the name should be register_trace_event()
instead.

Also renamed ftrace_event_reg() to trace_event_reg() for the same reason.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:05:14 -04:00
Steven Rostedt (Red Hat) 645df987f7 tracing: Rename ftrace_print_*() functions ta trace_print_*()
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The functions ftrace_print_*() are not part of
the function infrastructure, and the names can be confusing. Rename them
to be trace_print_*().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:05:13 -04:00
Steven Rostedt (Red Hat) af658dca22 tracing: Rename ftrace_event.h to trace_events.h
The term "ftrace" is really the infrastructure of the function hooks,
and not the trace events. Rename ftrace_event.h to trace_events.h to
represent the trace_event infrastructure and decouple the term ftrace
from it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13 14:05:12 -04:00
Chen Hanxiao b749b1b673 workqueue: fix a typo
s/detemined/determined

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-13 10:23:56 -04:00
Rafael J. Wysocki 819b1bb30d PM / sleep: Fix symbol name in a comment in kernel/power/main.c
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-13 15:31:12 +02:00
Sebastian Andrzej Siewior cede88418b locking/rtmutex: Drop usage of __HAVE_ARCH_CMPXCHG
The rtmutex code is the only user of __HAVE_ARCH_CMPXCHG and we have a few
other user of cmpxchg() which do not care about __HAVE_ARCH_CMPXCHG. This
define was first introduced in 23f78d4a0 ("[PATCH] pi-futex: rt mutex core")
which is v2.6.18. The generic cmpxchg was introduced later in 068fbad288
("Add cmpxchg_local to asm-generic for per cpu atomic operations") which is
v2.6.25.
Back then something was required to get rtmutex working with the fast
path on architectures without cmpxchg and this seems to be the result.

It popped up recently on rt-users because ARM (v6+) does not define
__HAVE_ARCH_CMPXCHG (even that it implements it) which results in slower
locking performance in the fast path.
To put some numbers on it: preempt -RT, am335x, 10 loops of
100000 invocations of rt_spin_lock() + rt_spin_unlock() (time "total" is
the average of the 10 loops for the 100000 invocations, "loop" is
"total / 100000 * 1000"):

     cmpxchg |    slowpath used  ||    cmpxchg used
             |   total   | loop  ||   total    | loop
     --------|-----------|-------||------------|-------
     ARMv6   | 9129.4 us | 91 ns ||  3311.9 us |  33 ns
     generic | 9360.2 us | 94 ns || 10834.6 us | 108 ns
     ----------------------------||--------------------

Forcing it to generic cmpxchg() made things worse for the slowpath and
even worse in cmpxchg() path. It boils down to 14ns more per lock+unlock
in a cache hot loop so it might not be that much in real world.
The last test was a substitute for pre ARMv6 machine but then I was able
to perform the comparison on imx28 which is ARMv5 and therefore is
always is using the generic cmpxchg implementation. And the numbers:

              |   total     | loop
     -------- |-----------  |--------
     slowpath | 263937.2 us | 2639 ns
     cmpxchg  |  16934.2 us |  169 ns
     --------------------------------

The numbers are larger since the machine is slower in general. However,
letting rtmutex use cmpxchg() instead the slowpath seem to improve things.

Since from the ARM (tested on am335x + imx28) point of view always
using cmpxchg() in rt_mutex_lock() + rt_mutex_unlock() makes sense I
would drop the define.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: will.deacon@arm.com
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20150225175613.GE6823@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-13 10:51:28 +02:00
Axel Lin 63781394c5 genirq: devres: Fix testing return value of request_any_context_irq()
request_any_context_irq() returns a negative value on failure.
It returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED on success.
So fix testing return value of request_any_context_irq().

Also fixup the return value of devm_request_any_context_irq() to make it
consistent with request_any_context_irq().

Fixes: 0668d30651 ("genirq: Add devm_request_any_context_irq()")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1431334978.17783.4.camel@ingics.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-13 10:47:37 +02:00
John Stultz f7bcb70eba ktime: Fix ktime_divns to do signed division
It was noted that the 32bit implementation of ktime_divns()
was doing unsigned division and didn't properly handle
negative values.

And when a ktime helper was changed to utilize
ktime_divns, it caused a regression on some IR blasters.
See the following bugzilla for details:
  https://bugzilla.redhat.com/show_bug.cgi?id=1200353

This patch fixes the problem in ktime_divns by checking
and preserving the sign bit, and then reapplying it if
appropriate after the division, it also changes the return
type to a s64 to make it more obvious this is expected.

Nicolas also pointed out that negative dividers would
cause infinite loops on 32bit systems, negative dividers
is unlikely for users of this function, but out of caution
this patch adds checks for negative dividers for both
32-bit (BUG_ON) and 64-bit(WARN_ON) versions to make sure
no such use cases creep in.

[ tglx: Hand an u64 to do_div() to avoid the compiler warning ]

Fixes: 166afb6451 'ktime: Sanitize ktime_to_us/ms conversion'
Reported-and-tested-by: Trevor Cordes <trevor@tecnopolis.ca>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1431118043-23452-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-13 10:19:35 +02:00
Rafael J. Wysocki a921504588 PM / sleep: Refine diagnostic messages in enter_state()
Some of the system suspend diagnostic messages related to
suspend-to-idle refer to it as "freeze sleep" or "freeze state"
while the others say "suspend-to-idle".  To reduce the possible
confusion that may result from that, refine the former either to
say "suspend to idle" too or to make it clearer that what is printed
is a state string written to /sys/power/state ("mem", "standby",
or "freeze").

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-12 23:45:12 +02:00
Drew Richardson aabfa5f28f ftrace: Provide trace clock monotonic raw
Expose the NMI safe accessor to the monotonic raw clock to the
tracer. The mono clock was added with commit
1b3e5c0936. The advantage of the
monotonic raw clock is that it will advance more constantly than the
monotonic clock.

Imagine someone is trying to optimize a particular program to reduce
instructions executed for a given workload while minimizing the effect
on runtime. Also suppose that NTP is running and potentially making
larger adjustments to the monotonic clock. If NTP is adjusting the
monotonic clock to advance more rapidly, the program will appear to
use fewer instructions per second but run longer than if the monotonic
raw clock had been used. The total number of instructions observed
would be the same regardless of the clock source used, but how it's
attributed to time would be affected.

Conversely if NTP is adjusting the monotonic clock to advance more
slowly, the program will appear to use more instructions per second
but run more quickly. Of course there are many sources that can cause
jitter in performance measurements on modern processors, but let's
remove NTP from the list.

The monotonic raw clock can also be useful for tracing early boot,
e.g. when debugging issues with NTP.

Link: http://lkml.kernel.org/r/20150508143037.GB1276@dreric01-Precision-T1650

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Drew Richardson <drew.richardson@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-12 15:58:58 -04:00
Jerry Snitselaar 7e255d346c tracing: Export tracing clock functions
Critical tracepoint hooks should never call anything that takes a lock,
so they are unable to call getrawmonotonic() or ktime_get().

Export the rest of the tracing clock functions so can be used in
tracepoint hooks.

Background: We have a customer that adds their own module and registers
a tracepoint hook to sched_wakeup. They were using ktime_get() for a
time source, but it grabs a seq lock and caused a deadlock to occur.

Link: http://lkml.kernel.org/r/1430406624-22609-1-git-send-email-jsnitsel@redhat.com

Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-12 15:56:57 -04:00
Waiman Long c7114b4e6c locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS
To be consistent with the queued spinlocks which use
CONFIG_QUEUED_SPINLOCKS config parameter, the one for the queued
rwlocks is now renamed to CONFIG_QUEUED_RWLOCKS.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431367031-36697-1-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-12 09:46:00 +02:00
Nicholas Mc Guire e76ff06a95 livepatch: match return value to function signature
klp_initialized() should return bool but is actually returning
struct kobject * - convert it to a boolean explicitly.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Jiri Slaby <jslaby@suse.cz
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-05-11 23:43:52 +02:00
Gong Zhaogang 30186c6fdc workqueue: function name in the comment differs from the real function name
modify wq_calc_node_mask to wq_calc_node_cpumask

Signed-off-by: Gong Zhaogang <gongzhaogang@inspur.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-11 11:03:34 -04:00
Ingo Molnar f7dc7fd1c0 Merge branch 'perf/urgent' into perf/core, to resolve conflicts
Conflicts:
	tools/perf/builtin-kmem.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11 11:56:27 +02:00
Ingo Molnar 62c7a1e9ae locking/pvqspinlock: Rename QUEUED_SPINLOCK to QUEUED_SPINLOCKS
Valentin Rothberg reported that we use CONFIG_QUEUED_SPINLOCKS
in arch/x86/kernel/paravirt_patch_32.c, while the symbol is
called CONFIG_QUEUED_SPINLOCK. (Note the extra 'S')

But the typo was natural: the proper English term for such
a generic object would be 'queued spinlocks' - so rename
this and related symbols accordingly to the plural form.

Reported-by: Valentin Rothberg <valentinrothberg@gmail.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11 09:52:09 +02:00
Waiman Long 52c9d2badd locking/pvqspinlock: Replace xchg() by the more descriptive set_mb()
The xchg() function was used in pv_wait_node() to set a certain
value and provide a memory barrier which is what the set_mb()
function is for.  This patch replaces the xchg() call by
set_mb().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11 09:51:52 +02:00
Linus Torvalds 9d88f22a81 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "Two patches from the irq departement:

   - a simple fix to make dummy_irq_chip usable for wakeup scenarios

   - removal of the gic arch_extn hackery.  Now that all users are
     converted we really want to get rid of the interface so people wont
     come up with new use cases"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: gic: Drop support for gic_arch_extn
  genirq: Set IRQCHIP_SKIP_SET_WAKE flag for dummy_irq_chip
2015-05-09 14:59:05 -07:00
Linus Torvalds 95f3b1f4b1 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A simple fix to actually shut down a detached device instead of
  keeping it active"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clockevents: Shutdown detached clockevent device
2015-05-09 14:57:49 -07:00
Daniel Borkmann ac67eb2c53 seccomp, filter: add and use bpf_prog_create_from_user from seccomp
Seccomp has always been a special candidate when it comes to preparation
of its filters in seccomp_prepare_filter(). Due to the extra checks and
filter rewrite it partially duplicates code and has BPF internals exposed.

This patch adds a generic API inside the BPF code code that seccomp can use
and thus keep it's filter preparation code minimal and better maintainable.
The other side-effect is that now classic JITs can add seccomp support as
well by only providing a BPF_LDX | BPF_W | BPF_ABS translation.

Tested with seccomp and BPF test suites.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Nicolas Schichan d9e12f42e5 seccomp: simplify seccomp_prepare_filter and reuse bpf_prepare_filter
Remove the calls to bpf_check_classic(), bpf_convert_filter() and
bpf_migrate_runtime() and let bpf_prepare_filter() take care of that
instead.

seccomp_check_filter() is passed to bpf_prepare_filter() so that it
gets called from there, after bpf_check_classic().

We can now remove exposure of two internal classic BPF functions
previously used by seccomp. The export of bpf_check_classic() symbol,
previously known as sk_chk_filter(), was there since pre git times,
and no in-tree module was using it, therefore remove it.

Joint work with Daniel Borkmann.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Linus Torvalds 26b293e854 The newly added ftrace_print_array_seq() function had a bug in it. Luckily,
the only user of it didn't make the 4.1 merge window. But the helper
 function should be fixed before 4.2 when the users start coming in.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJVTBNUAAoJEEjnJuOKh9ld0VQIAJWPLivGbGJyjSqFd1NXLidS
 ytcbM0dquYjvQ94EDxoA+uBm34hk1JbvcI+FgiOihEeyGh7wrhdibEVGT40TzE2I
 XrfTVwPfN5/k2D5MeZzzRkeoTDufc33MgqTURymRQSzkmHf5GttPXxZ/ckO9Hz9A
 XqzXaHcmnauZSmUY12q8rMtbKYP/dN5hUdmR6p44bMgDJehQkmTzJkxbe6t98b+t
 8y3YAcK5HclYITC2lBVHSw5z8e9F/B7UmrNxvNkcV5kqdYg3NnVnA292kSMft5zo
 WRk1nH4eVARq2dmGQ289QpneHqtMx22RU42m/t8M/v0OUANhlPaDb/RHlyDWJF4=
 =4JGY
 -----END PGP SIGNATURE-----

Merge tag 'trace-fixes-v4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "The newly added ftrace_print_array_seq() function had a bug in it.
  Luckily, the only user of it didn't make the 4.1 merge window.

  But the helper function should be fixed before 4.2 when the users
  start coming in"

* tag 'trace-fixes-v4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Make ftrace_print_array_seq compute buf_len
2015-05-08 18:22:05 -07:00
Shaohua Li 5596d0d591 sched: always use blk_schedule_flush_plug in io_schedule_out
block plug callback could sleep, so we introduce a parameter
'from_schedule' and corresponding drivers can use it to destinguish a
schedule plug flush or a plug finish. Unfortunately io_schedule_out
still uses blk_flush_plug(). This causes below output (Note, I added a
might_sleep() in raid1_unplug to make it trigger faster, but the whole
thing doesn't matter if I add might_sleep). In raid1/10, this can cause
deadlock.

This patch makes io_schedule_out always uses blk_schedule_flush_plug.
This should only impact drivers (as far as I know, raid 1/10) which are
sensitive to the 'from_schedule' parameter.

[  370.817949] ------------[ cut here ]------------
[  370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90()
[  370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90
[  370.817971] Modules linked in: raid1
[  370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G        W       4.0.0+ #361
[  370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014
[  370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1)
[  370.817985]  ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001
[  370.817988]  ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8
[  370.817990]  ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28
[  370.817993] Call Trace:
[  370.817999]  [<ffffffff819dd7af>] dump_stack+0x4f/0x7b
[  370.818002]  [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0
[  370.818004]  [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50
[  370.818006]  [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90
[  370.818008]  [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90
[  370.818010]  [<ffffffff810776ef>] __might_sleep+0x7f/0x90
[  370.818014]  [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1]
[  370.818024]  [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0
[  370.818028]  [<ffffffff819e3550>] ? bit_wait+0x50/0x50
[  370.818031]  [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140
[  370.818033]  [<ffffffff819e3586>] bit_wait_io+0x36/0x50
[  370.818034]  [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90
[  370.818041]  [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630
[  370.818043]  [<ffffffff819e3550>] ? bit_wait+0x50/0x50
[  370.818045]  [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80
[  370.818047]  [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40
[  370.818050]  [<ffffffff811de744>] __wait_on_buffer+0x44/0x50
[  370.818053]  [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0
[  370.818058]  [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790
[  370.818062]  [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50
[  370.818064]  [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200
[  370.818066]  [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360
[  370.818068]  [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0
[  370.818070]  [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0
[  370.818072]  [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460
[  370.818074]  [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0
[  370.818076]  [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620
[  370.818079]  [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0
[  370.818081]  [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290
[  370.818085]  [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0
[  370.818088]  [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50
[  370.818094]  [<ffffffff81149691>] do_writepages+0x21/0x50
[  370.818097]  [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490
[  370.818099]  [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590
[  370.818103]  [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50
[  370.818105]  [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50
[  370.818107]  [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0
[  370.818109]  [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0
[  370.818111]  [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550
[  370.818116]  [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570
[  370.818117]  [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570
[  370.818119]  [<ffffffff8106c09b>] worker_thread+0x11b/0x470
[  370.818121]  [<ffffffff8106bf80>] ? process_one_work+0x570/0x570
[  370.818124]  [<ffffffff81071868>] kthread+0xf8/0x110
[  370.818126]  [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210
[  370.818129]  [<ffffffff819e9322>] ret_from_fork+0x42/0x70
[  370.818131]  [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210
[  370.818132] ---[ end trace 7b4deb71e68b6605 ]---

V2: don't change ->in_iowait

Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:15 -06:00
Steven Rostedt 37815bf866 module: Call module notifier on failure after complete_formation()
The module notifier call chain for MODULE_STATE_COMING was moved up before
the parsing of args, into the complete_formation() call. But if the module failed
to load after that, the notifier call chain for MODULE_STATE_GOING was
never called and that prevented the users of those call chains from
cleaning up anything that was allocated.

Link: http://lkml.kernel.org/r/554C52B9.9060700@gmail.com

Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Fixes: 4982223e51 "module: set nx before marking module MODULE_STATE_COMING"
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-09 03:29:24 +09:30
David Vrabel e95e6f176c locking/pvqspinlock, x86: Enable PV qspinlock for Xen
This patch adds the necessary Xen specific code to allow Xen to
support the CPU halting and kicking operations needed by the queue
spinlock PV code.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-12-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:37:18 +02:00
Waiman Long bf0c7c34ad locking/pvqspinlock, x86: Enable PV qspinlock for KVM
This patch adds the necessary KVM specific code to allow KVM to
support the CPU halting and kicking operations needed by the queue
spinlock PV code.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-11-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:37:17 +02:00
Waiman Long a23db284fe locking/pvqspinlock: Implement simple paravirt support for the qspinlock
Provide a separate (second) version of the spin_lock_slowpath for
paravirt along with a special unlock path.

The second slowpath is generated by adding a few pv hooks to the
normal slowpath, but where those will compile away for the native
case, they expand into special wait/wake code for the pv version.

The actual MCS queue can use extra storage in the mcs_nodes[] array to
keep track of state and therefore uses directed wakeups.

The head contender has no such storage directly visible to the
unlocker.  So the unlocker searches a hash table with open addressing
using a simple binary Galois linear feedback shift register.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1429901803-29771-9-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:37:05 +02:00
Peter Zijlstra (Intel) 2aa79af642 locking/qspinlock: Revert to test-and-set on hypervisors
When we detect a hypervisor (!paravirt, see qspinlock paravirt support
patches), revert to a simple test-and-set lock to avoid the horrors
of queue preemption.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-8-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:58 +02:00
Waiman Long 2c83e8e949 locking/qspinlock: Use a simple write to grab the lock
Currently, atomic_cmpxchg() is used to get the lock. However, this
is not really necessary if there is more than one task in the queue
and the queue head don't need to reset the tail code. For that case,
a simple write to set the lock bit is enough as the queue head will
be the only one eligible to get the lock as long as it checks that
both the lock and pending bits are not set. The current pending bit
waiting code will ensure that the bit will not be set as soon as the
tail code in the lock is set.

With that change, the are some slight improvement in the performance
of the queued spinlock in the 5M loop micro-benchmark run on a 4-socket
Westere-EX machine as shown in the tables below.

		[Standalone/Embedded - same node]
  # of tasks	Before patch	After patch	%Change
  ----------	-----------	----------	-------
       3	 2324/2321	2248/2265	 -3%/-2%
       4	 2890/2896	2819/2831	 -2%/-2%
       5	 3611/3595	3522/3512	 -2%/-2%
       6	 4281/4276	4173/4160	 -3%/-3%
       7	 5018/5001	4875/4861	 -3%/-3%
       8	 5759/5750	5563/5568	 -3%/-3%

		[Standalone/Embedded - different nodes]
  # of tasks	Before patch	After patch	%Change
  ----------	-----------	----------	-------
       3	12242/12237	12087/12093	 -1%/-1%
       4	10688/10696	10507/10521	 -2%/-2%

It was also found that this change produced a much bigger performance
improvement in the newer IvyBridge-EX chip and was essentially to close
the performance gap between the ticket spinlock and queued spinlock.

The disk workload of the AIM7 benchmark was run on a 4-socket
Westmere-EX machine with both ext4 and xfs RAM disks at 3000 users
on a 3.14 based kernel. The results of the test runs were:

                AIM7 XFS Disk Test
  kernel                 JPM    Real Time   Sys Time    Usr Time
  -----                  ---    ---------   --------    --------
  ticketlock            5678233    3.17       96.61       5.81
  qspinlock             5750799    3.13       94.83       5.97

                AIM7 EXT4 Disk Test
  kernel                 JPM    Real Time   Sys Time    Usr Time
  -----                  ---    ---------   --------    --------
  ticketlock            1114551   16.15      509.72       7.11
  qspinlock             2184466    8.24      232.99       6.01

The ext4 filesystem run had a much higher spinlock contention than
the xfs filesystem run.

The "ebizzy -m" test was also run with the following results:

  kernel               records/s  Real Time   Sys Time    Usr Time
  -----                ---------  ---------   --------    --------
  ticketlock             2075       10.00      216.35       3.49
  qspinlock              3023       10.00      198.20       4.80

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-7-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:55 +02:00
Peter Zijlstra (Intel) 69f9cae909 locking/qspinlock: Optimize for smaller NR_CPUS
When we allow for a max NR_CPUS < 2^14 we can optimize the pending
wait-acquire and the xchg_tail() operations.

By growing the pending bit to a byte, we reduce the tail to 16bit.
This means we can use xchg16 for the tail part and do away with all
the repeated compxchg() operations.

This in turn allows us to unconditionally acquire; the locked state
as observed by the wait loops cannot change. And because both locked
and pending are now a full byte we can use simple stores for the
state transition, obviating one atomic operation entirely.

This optimization is needed to make the qspinlock achieve performance
parity with ticket spinlock at light load.

All this is horribly broken on Alpha pre EV56 (and any other arch that
cannot do single-copy atomic byte stores).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-6-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:48 +02:00
Waiman Long 6403bd7d0e locking/qspinlock: Extract out code snippets for the next patch
This is a preparatory patch that extracts out the following 2 code
snippets to prepare for the next performance optimization patch.

 1) the logic for the exchange of new and previous tail code words
    into a new xchg_tail() function.
 2) the logic for clearing the pending bit and setting the locked bit
    into a new clear_pending_set_locked() function.

This patch also simplifies the trylock operation before queuing by
calling queued_spin_trylock() directly.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-5-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:41 +02:00
Peter Zijlstra (Intel) c1fb159db9 locking/qspinlock: Add pending bit
Because the qspinlock needs to touch a second cacheline (the per-cpu
mcs_nodes[]); add a pending bit and allow a single in-word spinner
before we punt to the second cacheline.

It is possible so observe the pending bit without the locked bit when
the last owner has just released but the pending owner has not yet
taken ownership.

In this case we would normally queue -- because the pending bit is
already taken. However, in this case the pending bit is guaranteed
to be released 'soon', therefore wait for it and avoid queueing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-4-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:32 +02:00
Waiman Long a33fda35e3 locking/qspinlock: Introduce a simple generic 4-byte queued spinlock
This patch introduces a new generic queued spinlock implementation that
can serve as an alternative to the default ticket spinlock. Compared
with the ticket spinlock, this queued spinlock should be almost as fair
as the ticket spinlock. It has about the same speed in single-thread
and it can be much faster in high contention situations especially when
the spinlock is embedded within the data structure to be protected.

Only in light to moderate contention where the average queue depth
is around 1-3 will this queued spinlock be potentially a bit slower
due to the higher slowpath overhead.

This queued spinlock is especially suit to NUMA machines with a large
number of cores as the chance of spinlock contention is much higher
in those machines. The cost of contention is also higher because of
slower inter-node memory traffic.

Due to the fact that spinlocks are acquired with preemption disabled,
the process will not be migrated to another CPU while it is trying
to get a spinlock. Ignoring interrupt handling, a CPU can only be
contending in one spinlock at any one time. Counting soft IRQ, hard
IRQ and NMI, a CPU can only have a maximum of 4 concurrent lock waiting
activities.  By allocating a set of per-cpu queue nodes and used them
to form a waiting queue, we can encode the queue node address into a
much smaller 24-bit size (including CPU number and queue node index)
leaving one byte for the lock.

Please note that the queue node is only needed when waiting for the
lock. Once the lock is acquired, the queue node can be released to
be used later.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:25 +02:00
Waiman Long 59aabfc7e9 locking/rwsem: Reduce spinlock contention in wakeup after up_read()/up_write()
In up_write()/up_read(), rwsem_wake() will be called whenever it
detects that some writers/readers are waiting. The rwsem_wake()
function will take the wait_lock and call __rwsem_do_wake() to do the
real wakeup.  For a heavily contended rwsem, doing a spin_lock() on
wait_lock will cause further contention on the heavily contended rwsem
cacheline resulting in delay in the completion of the up_read/up_write
operations.

This patch makes the wait_lock taking and the call to __rwsem_do_wake()
optional if at least one spinning writer is present. The spinning
writer will be able to take the rwsem and call rwsem_wake() later
when it calls up_write(). With the presence of a spinning writer,
rwsem_wake() will now try to acquire the lock using trylock. If that
fails, it will just quit.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Jason Low <jason.low2@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430428337-16802-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:27:59 +02:00
Peter Zijlstra ff303e66c2 perf: Fix software migrate events
Stephane asked about PERF_COUNT_SW_CPU_MIGRATIONS and I realized it
was borken:

 > The problem is that the task isn't actually scheduled while its being
 > migrated (obviously), and if its not scheduled, the counters aren't
 > scheduled either, so there's no observing of the fact.
 >
 > A further problem with migrations is that many migrations happen from
 > softirq context, which is nested inside the 'random' task context of
 > whoemever happens to run at that time, similarly for the wakeup
 > migrations triggered from (soft)irq context. All those end up being
 > accounted in the task that's currently running, eg. your 'ls'.

The below cures this by marking a task as migrated and accounting it
on the subsequent sched_in().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:25:38 +02:00
Davidlohr Bueso 1d0dcb3ad9 futex: Implement lockless wakeups
Given the overall futex architecture, any chance of reducing
hb->lock contention is welcome. In this particular case, using
wake-queues to enable lockless wakeups addresses very much real
world performance concerns, even cases of soft-lockups in cases
of large amounts of blocked tasks (which is not hard to find in
large boxes, using but just a handful of futex).

At the lowest level, this patch can reduce latency of a single thread
attempting to acquire hb->lock in highly contended scenarios by a
up to 2x. At lower counts of nr_wake there are no regressions,
confirming, of course, that the wake_q handling overhead is practically
non existent. For instance, while a fair amount of variation,
the extended pef-bench wakeup benchmark shows for a 20 core machine
the following avg per-thread time to wakeup its share of tasks:

	nr_thr	ms-before	ms-after
	16 	0.0590		0.0215
	32 	0.0396		0.0220
	48 	0.0417		0.0182
	64 	0.0536		0.0236
	80 	0.0414		0.0097
	96 	0.0672		0.0152

Naturally, this can cause spurious wakeups. However there is no core code
that cannot handle them afaict, and furthermore tglx does have the point
that other events can already trigger them anyway.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: George Spelvin <linux@horizon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430494072-30283-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:21:40 +02:00
Peter Zijlstra 7675104990 sched: Implement lockless wake-queues
This is useful for locking primitives that can effect multiple
wakeups per operation and want to avoid lock internal lock contention
by delaying the wakeups until we've released the lock internal locks.

Alternatively it can be used to avoid issuing multiple wakeups, and
thus save a few cycles, in packet processing. Queue all target tasks
and wakeup once you've processed all packets. That way you avoid
waking the target task multiple times if there were multiple packets
for the same task.

Properties of a wake_q are:
- Lockless, as queue head must reside on the stack.
- Being a queue, maintains wakeup order passed by the callers. This can
  be important for otherwise, in scenarios where highly contended locks
  could affect any reliance on lock fairness.
- A queued task cannot be added again until it is woken up.

This patch adds the needed infrastructure into the scheduler code
and uses the new wake_list to delay the futex wakeups until
after we've released the hash bucket locks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[tweaks, adjustments, comments, etc.]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: George Spelvin <linux@horizon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430494072-30283-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:20:45 +02:00
Jason Low 7110744516 sched, timer: Use the atomic task_cputime in thread_group_cputimer
Recent optimizations were made to thread_group_cputimer to improve its
scalability by keeping track of cputime stats without a lock. However,
the values were open coded to the structure, causing them to be at
a different abstraction level from the regular task_cputime structure.
Furthermore, any subsequent similar optimizations would not be able to
share the new code, since they are specific to thread_group_cputimer.

This patch adds the new task_cputime_atomic data structure (introduced in
the previous patch in the series) to thread_group_cputimer for keeping
track of the cputime atomically, which also helps generalize the code.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1430251224-5764-6-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:17:46 +02:00
Jason Low 1018016c70 sched, timer: Replace spinlocks with atomics in thread_group_cputimer(), to improve scalability
While running a database workload, we found a scalability issue with itimers.

Much of the problem was caused by the thread_group_cputimer spinlock.
Each time we account for group system/user time, we need to obtain a
thread_group_cputimer's spinlock to update the timers. On larger systems
(such as a 16 socket machine), this caused more than 30% of total time
spent trying to obtain this kernel lock to update these group timer stats.

This patch converts the timers to 64-bit atomic variables and use
atomic add to update them without a lock. With this patch, the percent
of total time spent updating thread group cputimer timers was reduced
from 30% down to less than 1%.

Note: On 32-bit systems using the generic 64-bit atomics, this causes
sample_group_cputimer() to take locks 3 times instead of just 1 time.
However, we tested this patch on a 32-bit system ARM system using the
generic atomics and did not find the overhead to be much of an issue.
An explanation for why this isn't an issue is that 32-bit systems usually
have small numbers of CPUs, and cacheline contention from extra spinlocks
called periodically is not really apparent on smaller systems.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1430251224-5764-4-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:15:31 +02:00
Jason Low 7e5a2c1729 sched/numa: Document usages of mm->numa_scan_seq
The p->mm->numa_scan_seq is accessed using READ_ONCE/WRITE_ONCE
and modified without exclusive access. It is not clear why it is
accessed this way. This patch provides some documentation on that.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <waiman.long@hp.com>
Link: http://lkml.kernel.org/r/1430440094.2475.61.camel@j-VirtualBox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:13:13 +02:00
Jason Low 316c1608d1 sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE()
ACCESS_ONCE doesn't work reliably on non-scalar types. This patch removes
the rest of the existing usages of ACCESS_ONCE() in the scheduler, and use
the new READ_ONCE() and WRITE_ONCE() APIs as appropriate.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Waiman Long <Waiman.Long@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430251224-5764-2-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:11:32 +02:00
Nicholas Mc Guire ce2f5fe463 sched/core: Remove unnecessary down/up conversion
'rt_period_us' is automatically type converted from u64 to long and then cast
back to u64 - this down/up conversion is unnecessary and can be removed to
improve readability.

This will also help us not truncate 'rt_period_us' to 32 bits on 32-bit kernels,
should we ever have so large values. (unlikely, not the least due to procfs.)

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430643116-24049-1-git-send-email-hofrat@osadl.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:10:07 +02:00
Palmer Dabbelt b76808e680 signals, sched: Change all uses of JOBCTL_* from 'int' to 'long'
c56fb6564dcd ("Fix a misaligned load inside ptrace_attach()") makes
jobctl an "unsigned long".  It makes sense to have the masks applied
to it match that type.  This is currently just a cosmetic change, but
it will prevent the mask from being unexpectedly truncated if we ever
end up with masks with more bits.

One instance of "signr" is an int, but I left this alone because the
mask ensures that it will never overflow.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bobby.prani@gmail.com
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: richard@nod.at
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/1430453997-32459-4-git-send-email-palmer@dabbelt.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:04:36 +02:00
Peter Zijlstra 3289bdb429 sched: Move the loadavg code to a more obvious location
I could not find the loadavg code.. turns out it was hidden in a file
called proc.c. It further got mingled up with the cruft per rq load
indexes (which we really want to get rid of).

Move the per rq load indexes into the fair.c load-balance code (that's
the only thing that uses them) and rename proc.c to loadavg.c so we
can find it again.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
[ Did minor cleanups to the code. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:04:12 +02:00
Ingo Molnar bb2ebf0886 Merge branch 'sched/urgent' into sched/core, before applying new patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:59:57 +02:00
Peter Zijlstra 8b10c5e2b5 perf: Annotate inherited event ctx->mutex recursion
While fuzzing Sasha tripped over another ctx->mutex recursion lockdep
splat. Annotate this.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:59:40 +02:00
Paul Gortmaker 6a82b60da2 sched/core: Remove __cpuinit section tag that crept back in
We removed __cpuinit support (leaving no-op stubs) quite some time
ago.  However this one crept back in as of commit a803f0261b
("sched: Initialize rq->age_stamp on processor start")

Since we want to clobber the stubs too, get this removed now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430174880-27958-2-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:54:43 +02:00
Omar Sandoval 533445c6e5 sched/core: Fix regression in cpuset_cpu_inactive() for suspend
Commit 3c18d447b3 ("sched/core: Check for available DL bandwidth in
cpuset_cpu_inactive()"), a SCHED_DEADLINE bugfix, had a logic error that
caused a regression in setting a CPU inactive during suspend. I ran into
this when a program was failing pthread_setaffinity_np() with EINVAL after
a suspend+wake up.

A simple reproducer:

	$ ./a.out
	sched_setaffinity: Success
	$ systemctl suspend
	$ ./a.out
	sched_setaffinity: Invalid argument

... where ./a.out is:

	#define _GNU_SOURCE
	#include <errno.h>
	#include <sched.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	int main(void)
	{
		long num_cores;
		cpu_set_t cpu_set;
		int ret;

		num_cores = sysconf(_SC_NPROCESSORS_ONLN);
		CPU_ZERO(&cpu_set);
		CPU_SET(num_cores - 1, &cpu_set);
		errno = 0;
		ret = sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set);
		perror("sched_setaffinity");
		return ret ? EXIT_FAILURE : EXIT_SUCCESS;
	}

The mistake is that suspend is handled in the action ==
CPU_DOWN_PREPARE_FROZEN case of the switch statement in
cpuset_cpu_inactive().

However, the commit in question masked out CPU_TASKS_FROZEN
from the action, making this case dead.

The fix is straightforward.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 3c18d447b3 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()")
Link: http://lkml.kernel.org/r/1cb5ecb3d6543c38cce5790387f336f54ec8e2bc.1430733960.git.osandov@osandov.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:53:56 +02:00
Thomas Gleixner 0782e63bc6 sched: Handle priority boosted tasks proper in setscheduler()
Ronny reported that the following scenario is not handled correctly:

	T1 (prio = 10)
	   lock(rtmutex);

	T2 (prio = 20)
	   lock(rtmutex)
	      boost T1

	T1 (prio = 20)
	   sys_set_scheduler(prio = 30)
	   T1 prio = 30
	   ....
	   sys_set_scheduler(prio = 10)
	   T1 prio = 30

The last step is wrong as T1 should now be back at prio 20.

Commit c365c292d0 ("sched: Consider pi boosting in setscheduler()")
only handles the case where a boosted tasks tries to lower its
priority.

Fix it by taking the new effective priority into account for the
decision whether a change of the priority is required.

Reported-by: Ronny Meeus <ronny.meeus@gmail.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Fixes: c365c292d0 ("sched: Consider pi boosting in setscheduler()")
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505051806060.4225@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:53:55 +02:00
Ingo Molnar ed7b40c90e Merge branch 'sched/urgent' into sched/core
So this isn't really a fix but a cleanup that can wait for v4.2.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:50:24 +02:00
Thomas Gleixner 6b442bc813 nohz: Fix !HIGH_RES_TIMERS hang
Simon Horman reported this crash on a system with
high-res timers disabled but nohz enabled:

  > ------------[ cut here ]------------
  > kernel BUG at kernel/irq_work.c:135!

    BUG_ON(!irqs_disabled());

So something enabled interrupts in the periodic tick handling machinery,
and that code path indeed has a local_irq_disable()/enable pair in
tick_nohz_switch_to_nohz() which causes havoc. Fix it.

This patch also fixes a +nohz -hrtimers hang reported by Ingo Molnar.

Reported-by: Simon Horman <horms@verge.net.au>
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: LAK <linux-arm-kernel@lists.infradead.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505071425520.4225@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 16:15:50 +02:00
Chris Metcalf 8cb9764fc8 nohz: Set isolcpus when nohz_full is set
nohz_full is only useful with isolcpus are also set, since
otherwise the scheduler has to run periodically to try to
determine whether to steal work from other cores.

Accordingly, when booting with nohz_full=xxx on the command
line, we should act as if isolcpus=xxx was also set, and set
(or extend) the isolcpus set to include the nohz_full cpus.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Jones <davej@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430928266-24888-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 12:02:51 +02:00
Frederic Weisbecker fafe870f31 context_tracking: Inherit TIF_NOHZ through forks instead of context switches
TIF_NOHZ is used by context_tracking to force syscall slow-path
on every task in order to track userspace roundtrips. As such,
it must be set on all running tasks.

It's currently explicitly inherited through context switches.
There is no need to do it in this fast-path though. The flag
could simply be set once for all on all tasks, whether they are
running or not.

Lets do this by setting the flag for the init task on early boot,
and let it propagate through fork inheritance.

While at it, mark context_tracking_cpu_set() as init code, we
only need it at early boot time.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Dave Jones <davej@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430928266-24888-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 12:02:51 +02:00
Frederic Weisbecker aed5ed4772 context_tracking: Protect against recursion
Context tracking recursion can happen when an exception triggers
in the middle of a call to a context tracking probe.

This special case can be caused by vmalloc faults. If an access
to a memory area allocated by vmalloc happens in the middle of
context_tracking_enter(), we may run into an endless fault loop
because the exception in turn calls context_tracking_enter()
which faults on the same vmalloc'ed memory, triggering an
exception again, etc...

Some rare crashes have been reported so lets protect against
this with a recursion counter.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430928266-24888-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 12:02:50 +02:00
Alex Bennée ac01ce1410 tracing: Make ftrace_print_array_seq compute buf_len
The only caller to this function (__print_array) was getting it wrong by
passing the array length instead of buffer length. As the element size
was already being passed for other reasons it seems reasonable to push
the calculation of buffer length into the function.

Link: http://lkml.kernel.org/r/1430320727-14582-1-git-send-email-alex.bennee@linaro.org

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-06 23:03:23 -04:00
Linus Torvalds 02f0f5721e Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU fix from Ingo Molnar:
 "An RCU Kconfig fix that eliminates an annoying interactive kconfig
  question for CONFIG_RCU_TORTURE_TEST_SLOW_INIT"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Control grace-period delays directly from value
2015-05-06 10:26:37 -07:00
Andreas Sandberg 38d23a6cc1 tick: hrtimer-broadcast: Prevent endless restarting when broadcast device is unused
The hrtimer callback in the hrtimer's tick broadcast code sometimes
incorrectly ends up scheduling events at the current tick causing the
kernel to hang servicing the same hrtimer forever. This typically
happens when a device is swapped out by
tick_install_broadcast_device(), which replaces the event handler with
clock_events_handle_noop() and sets the device mode to
CLOCK_EVT_MODE_UNUSED. If the timer is scheduled when this happens,
the next_event field will not be updated and the hrtimer ends up being
restarted at the current tick. To prevent this from happening, only
try to restart the hrtimer if the broadcast clock event device is in
one of the active modes and try to cancel the timer when entering the
CLOCK_EVT_MODE_UNUSED mode.

Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1429880765-5558-1-git-send-email-andreas.sandberg@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 15:34:21 +02:00
Nicholas Mc Guire 7df0b27838 genirq: Fix type inconsistency
The return type of kstat_irqs_usr() is unsigned int and kstat_irqs() also
returns unsigned int so sum should be unsigned int here as well. 

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Link: http://lkml.kernel.org/r/1430642951-23964-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:45:58 +02:00
Nicholas Mc Guire 5e9662fa51 genirq: Fix unnecessary automatic type conversion
kstat_irqs is unsigned int and the return type of kstat_irqs() is also
unsigned int so sum should be unsigned int as well even if the result
is correct due to automatic type conversion.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Link: http://lkml.kernel.org/r/1430642930-23929-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:45:58 +02:00
Krzysztof Kozlowski 01364028bd genirq: MSI: Constify irq_domain_ops
The irq_domain_ops are not modified. The irqdomain core code accepts
pointer to a const data.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Link: http://lkml.kernel.org/r/1430139264-4362-1-git-send-email-k.kozlowski.k@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:45:58 +02:00
Joonwoo Park 781978e6e1 timer: Use timer->base for flag checks
At present, internal_add_timer() examines flags with 'base' which doesn't
contain flags.  Examine with 'timer->base' to avoid unnecessary waking up
of nohz CPU when timer base has TIMER_DEFERRABLE set.

Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Cc: sboyd@codeaurora.org
Cc: skannan@codeaurora.org
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1430187709-21087-1-git-send-email-joonwoop@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:40:43 +02:00
Preeti U Murthy 1ef09cd713 tick-broadcast: Fix the printing of broadcast masks
Today the number of bits of the broadcast masks that is output into
/proc/timer_list is sizeof(unsigned long). This means that on machines
with a larger number of CPUs, the bitmasks of CPUs beyond this range do
not appear.

Fix this by using bitmap printing through "%*pb" instead, so as to
output the broadcast masks for the range of nr_cpu_ids into
/proc/timer_list.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: peterz@infradead.org
Cc: linuxppc-dev@ozlabs.org
Cc: john.stultz@linaro.org
Link: http://lkml.kernel.org/r/20150428084520.3314.62668.stgit@preeti.in.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:35:58 +02:00
Thomas Gleixner 298dbd1c5c tick: broadcast: Simplify oneshot logic and shorten lock region
Simplify the oneshot logic by avoiding the reprogramming loops. That
also allows to call the cpu local handler outside of the
broadcast_lock held region.

Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:25:23 +02:00
Thomas Gleixner 2951d5c031 tick: broadcast: Prevent livelock from event handler
With the removal of the hrtimer softirq the switch to highres/nohz
mode happens in the tick interrupt. That leads to a livelock when the
per cpu event handler is directly called from the broadcast handler
under broadcast lock because broadcast lock needs to be taken for the
highres/nohz switch as well.

Solve this by calling the cpu local handler outside the broadcast_lock
held region.

Fixes: c6eb3f70d4 "hrtimer: Get rid of hrtimer softirq"
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 10:25:23 +02:00
Rafael J. Wysocki bcf6ad8a4a sched / idle: Eliminate the "reflect" check from cpuidle_idle_call()
Since cpuidle_reflect() should only be called if the idle state
to enter was selected by cpuidle_select(), there is the "reflect"
variable in cpuidle_idle_call() whose value is used to determine
whether or not that is the case.

However, if the entire code run between the conditional setting
"reflect" and the call to cpuidle_reflect() is moved to a separate
function, it will be possible to call that new function in both
branches of the conditional, in which case cpuidle_reflect() will
only need to be called from one of them too and the "reflect"
variable won't be necessary any more.

This eliminates one check made by cpuidle_idle_call() on the majority
of its invocations, so change the code as described.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-05-04 22:53:35 +02:00
Rafael J. Wysocki 82f663277d sched / idle: Move the default idle call code to a separate function
Move the code under the "use_default" label in cpuidle_idle_call()
into a separate (new) function.

This just allows the subsequent changes to be more stratightforward.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-05-04 22:53:22 +02:00
Thomas Gleixner 30fbd59057 perf: Remove unused function perf_mux_hrtimer_cancel()
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-04 13:51:40 +02:00
Linus Torvalds 6c3c1eb3c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Receive packet length needs to be adjust by 2 on RX to accomodate
    the two padding bytes in altera_tse driver.  From Vlastimil Setka.

 2) If rx frame is dropped due to out of memory in macb driver, we leave
    the receive ring descriptors in an undefined state.  From Punnaiah
    Choudary Kalluri

 3) Some netlink subsystems erroneously signal NLM_F_MULTI.  That is
    only for dumps.  Fix from Nicolas Dichtel.

 4) Fix mis-use of raw rt->rt_pmtu value in ipv4, one must always go via
    the ipv4_mtu() helper.  From Herbert Xu.

 5) Fix null deref in bridge netfilter, and miscalculated lengths in
    jump/goto nf_tables verdicts.  From Florian Westphal.

 6) Unhash ping sockets properly.

 7) Software implementation of BPF divide did 64/32 rather than 64/64
    bit divide.  The JITs got it right.  Fix from Alexei Starovoitov.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (30 commits)
  ipv4: Missing sk_nulls_node_init() in ping_unhash().
  net: fec: Fix RGMII-ID mode
  net/mlx4_en: Schedule napi when RX buffers allocation fails
  netxen_nic: use spin_[un]lock_bh around tx_clean_lock
  net/mlx4_core: Fix unaligned accesses
  mlx4_en: Use correct loop cursor in error path.
  cxgb4: Fix MC1 memory offset calculation
  bnx2x: Delay during kdump load
  net: Fix Kernel Panic in bonding driver debugfs file: rlb_hash_table
  net: dsa: Fix scope of eeprom-length property
  net: macb: Fix race condition in driver when Rx frame is dropped
  hv_netvsc: Fix a bug in netvsc_start_xmit()
  altera_tse: Correct rx packet length
  mlx4: Fix tx ring affinity_mask creation
  tipc: fix problem with parallel link synchronization mechanism
  tipc: remove wrong use of NLM_F_MULTI
  bridge/nl: remove wrong use of NLM_F_MULTI
  bridge/mdb: remove wrong use of NLM_F_MULTI
  net: sched: act_connmark: don't zap skb->nfct
  trivial: net: systemport: bcmsysport.h: fix 0x0x prefix
  ...
2015-05-01 20:51:04 -07:00
Linus Torvalds 4a152c3913 Power management and ACPI fixes for v4.1-rc2
- Fix for a regression in the cpuidle core introduced by one of
    the recent commits in the clockevents_notify() removal series
    that put a call to a function which had to be executed with
    disabled interrupts into a code path running with enabled
    interrupts (Rafael J Wysocki).
 
  - Fix for a build problem in ACPICA (with GCC 4.5) introduced by one
    of the recent ACPICA tools commits that added a duplicate typedef
    to one of the ACPICA's header files by mistake (Olaf Hering).
 
  - Fix for a regression in the ACPI SBS (Smart Battery Subsystem)
    driver introduced during the 3.18 development cycle causing the
    smart battery manager to be marked as not present when it should
    be marked as present (Chris Bainbridge).
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJVQoeSAAoJEILEb/54YlRxuscP/3Vz98JY0P7sMLnxVU8RPBxW
 cBN7G7F1gZup66/yV3MzvYHbgOFwNdQ2aMVxN+qV7rVMw27uwHljVr3svB+/GS15
 TeyKxvFWZYwhPKdsNAoHdkGBsptAK4DdyA+N2wH3MZ4dd8HepxpBG6QvzaEt4s43
 wFhhFrzEP3HDjrPoF/7TwKbsSrFuU5/U5PTd3dIuukj6JAl0PWnjczuVsg1PRyCW
 9kvefs3U56s8GbWOhDC+QyQ3eYJ2y35j/XnCKFWwljcdnis6HpsKj+oxSG2o0K4o
 9LLL3MgnTQuFbenuFIJUsMdFFdFrFkEeiV1EAdKCzQcXdlipxvi2cPttdNWVd6eZ
 JobXyhq7iYUQK5E5Dp6TCokxhzOyjvTo7VmEkkkqLVmfeO0FnggUAduRMAIacYXS
 ZML45m4UtvCJRoQXXxyzwYQXFeRD/nJQlOavC95jGGqtAij0Xk4xqTauQKIiqiaE
 zobOJ5ZxJMP+njFfzyDxjm68LjobYm1fUJTpWzpUSExjEKImRcw/QMzw23MyHHUL
 IJ7hP8FcELglkZWk/0ZwoNhbwM5Q2qGX5WMtqyunNFcf83aBsCr8bSjOrm4zmuL7
 NWjjeXuYwzPuC7SnFqf2K/CCfdkrdnU1frKLTpOm8t8W0P4mr1ckYrPemNemr8sN
 e5GozK5m13T2gTT4+q6M
 =v78a
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "Three regression fixes this time, one for a recent regression in the
  cpuidle core affecting multiple systems, one for an inadvertently
  added duplicate typedef in ACPICA that breaks compilation with GCC 4.5
  and one for an ACPI Smart Battery Subsystem driver regression
  introduced during the 3.18 cycle (stable-candidate).

  Specifics:

   - Fix for a regression in the cpuidle core introduced by one of the
     recent commits in the clockevents_notify() removal series that put
     a call to a function which had to be executed with disabled
     interrupts into a code path running with enabled interrupts (Rafael
     J Wysocki)

   - Fix for a build problem in ACPICA (with GCC 4.5) introduced by one
     of the recent ACPICA tools commits that added a duplicate typedef
     to one of the ACPICA's header files by mistake (Olaf Hering)

   - Fix for a regression in the ACPI SBS (Smart Battery Subsystem)
     driver introduced during the 3.18 development cycle causing the
     smart battery manager to be marked as not present when it should be
     marked as present (Chris Bainbridge)"

* tag 'pm+acpi-4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: Run tick_broadcast_exit() with disabled interrupts
  ACPI / SBS: Enable battery manager when present
  ACPICA: remove duplicate u8 typedef
2015-04-30 14:23:31 -07:00
Linus Torvalds 9dbbe3cfc3 Remove from guest code the handling of task migration during a
pvclock read; instead use the correct protocol in KVM.
 
 This removes the need for task migration notifiers in core
 scheduler code.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJVQkUWAAoJEL/70l94x66DhfcH/A8RTHUOELtoy+v2weahn21m
 FFWEnEUlCWzYgmiddgFdlr6+ub386W3ryFsXKPqjrn/8LVv3yS7tK1NJF8d03LQw
 n7HtIsrF01E9UI8CIWO4S/mUxWQev6vEJ9NXtNrsJcRmhSeLaIZkPjTH8Zqyx4i9
 ZvG4731WHXmxvbJ03bfJU9Y8OwHXe55GMi614aTxPndVBGdvIRu2Oj6aTfQTeab/
 7tEujub0MKWp74a7eyNU4GItcvIAXZCQt2wMc5dN1VK3ma5FTOnHIOuhAb8mACFF
 qEeGhtxAnOf7W+s9J8i7zVBdA5MOS0vUKng361ZOVGDb0OLqcVADW7GpuTZfRAM=
 =2A7v
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm changes from Paolo Bonzini:
 "Remove from guest code the handling of task migration during a pvclock
  read; instead use the correct protocol in KVM.

  This removes the need for task migration notifiers in core scheduler
  code"

[ The scheduler people really hated the migration notifiers, so this was
  kind of required  - Linus ]

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86: pvclock: Really remove the sched notifier for cross-cpu migrations
  kvm: x86: fix kvmclock update protocol
2015-04-30 09:44:04 -07:00
David Howells 9c4249c8e0 modsign: change default key details
Change default key details to be more obviously unspecified.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-30 09:35:41 -07:00
Lai Jiangshan 042f7df15a workqueue: Allow modifying low level unbound workqueue cpumask
Allow to modify the low-level unbound workqueues cpumask through
sysfs. This is performed by traversing the entire workqueue list
and calling apply_wqattrs_prepare() on the unbound workqueues
with the new low level mask. Only after all the preparation are done,
we commit them all together.

Ordered workqueues are ignored from the low level unbound workqueue
cpumask, it will be handled in near future.

All the (default & per-node) pwqs are mandatorily controlled by
the low level cpumask. If the user configured cpumask doesn't overlap
with the low level cpumask, the low level cpumask will be used for the
wq instead.

The comment of wq_calc_node_cpumask() is updated and explicitly
requires that its first argument should be the attrs of the default
pwq.

The default wq_unbound_cpumask is cpu_possible_mask.  The workqueue
subsystem doesn't know its best default value, let the system manager
or the other subsystem set it when needed.

Changed from V8:
  merge the calculating code for the attrs of the default pwq together.
  minor change the code&comments for saving the user configured attrs.
  remove unnecessary list_del().
  minor update the comment of wq_calc_node_cpumask().
  update the comment of workqueue_set_unbound_cpumask();

Cc: Christoph Lameter <cl@linux.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Original-patch-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-04-30 09:24:29 -04:00
Jiri Kosina 5d4351ba65 livepatch: x86: make kASLR logic more accurate
We give up old_addr hint from the coming patch module in cases when kernel load
base has been randomized (as in such case, the coming module has no idea about
the exact randomization offset).

We are currently too pessimistic, and give up immediately as soon as
CONFIG_RANDOMIZE_BASE is set; this doesn't however directly imply that the
load base has actually been randomized. There are config options that
disable kASLR (such as hibernation), user could have disabled kaslr on
kernel command-line, etc.

The loader propagates the information whether kernel has been randomized
through bootparams. This allows us to have the condition more accurate.

On top of that, it seems unnecessary to give up old_addr hints even if
randomization is active. The relocation offset can be computed using
kaslr_ofsset(), and therefore old_addr can be adjusted accordingly.

Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-04-29 16:51:33 +02:00
Rafael J. Wysocki df8d9eeadd cpuidle: Run tick_broadcast_exit() with disabled interrupts
Commit 335f49196f (sched/idle: Use explicit broadcast oneshot
control function) replaced clockevents_notify() invocations in
cpuidle_idle_call() with direct calls to tick_broadcast_enter()
and tick_broadcast_exit(), but it overlooked the fact that
interrupts were already enabled before calling the latter which
led to functional breakage on systems using idle states with the
CPUIDLE_FLAG_TIMER_STOP flag set.

Fix that by moving the invocations of tick_broadcast_enter()
and tick_broadcast_exit() down into cpuidle_enter_state() where
interrupts are still disabled when tick_broadcast_exit() is
called.  Also ensure that interrupts will be disabled before
running tick_broadcast_exit() even if they have been enabled by
the idle state's ->enter callback.  Trigger a WARN_ON_ONCE() in
that case, as we generally don't want that to happen for states
with CPUIDLE_FLAG_TIMER_STOP set.

Fixes: 335f49196f (sched/idle: Use explicit broadcast oneshot control function)
Reported-and-tested-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-04-29 15:19:21 +02:00
Linus Torvalds 14bc84ce0b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "One additional new feature for 4.1, a new PRNG based on SHA-512 for
  the zcrypt driver.

  Two memory management related changes, the page table reallocation for
  KVM is removed, and with file ptes gone the encoding of page table
  entries is improved.

  And three bug fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: Introduce new SHA-512 based Pseudo Random Generator.
  s390/mm: change swap pte encoding and pgtable cleanup
  s390/mm: correct transfer of dirty & young bits in __pmd_to_pte
  s390/bpf: add dependency to z196 features
  s390/3215: free memory in error path
  s390/kvm: remove delayed reallocation of page tables for KVM
  kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP
2015-04-28 09:58:46 -07:00
Alexei Starovoitov 876a7ae65b bpf: fix 64-bit divide
ALU64_DIV instruction should be dividing 64-bit by 64-bit,
whereas do_div() does 64-bit by 32-bit divide.
x64 and arm64 JITs correctly implement 64 by 64 unsigned divide.
llvm BPF backend emits code assuming that ALU64_DIV does 64 by 64.

Fixes: 89aa075832 ("net: sock: allow eBPF programs to be attached to sockets")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-27 23:11:49 -04:00
Frederic Weisbecker b05a79280b workqueue: Create low-level unbound workqueues cpumask
Create a cpumask that limits the affinity of all unbound workqueues.
This cpumask is controlled through a file at the root of the workqueue
sysfs directory.

It works on a lower-level than the per WQ_SYSFS workqueues cpumask files
such that the effective cpumask applied for a given unbound workqueue is
the intersection of /sys/devices/virtual/workqueue/$WORKQUEUE/cpumask and
the new /sys/devices/virtual/workqueue/cpumask file.

This patch implements the basic infrastructure and the read interface.
wq_unbound_cpumask is initially set to cpu_possible_mask.

Cc: Christoph Lameter <cl@linux.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-04-27 11:13:40 -04:00
Lai Jiangshan 2d5f0764b5 workqueue: split apply_workqueue_attrs() into 3 stages
Current apply_workqueue_attrs() includes pwqs-allocation and pwqs-installation,
so when we batch multiple apply_workqueue_attrs()s as a transaction, we can't
ensure the transaction must succeed or fail as a complete unit.

To solve this, we split apply_workqueue_attrs() into three stages.
The first stage does the preparation: allocation memory, pwqs.
The second stage does the attrs-installaion and pwqs-installation.
The third stage frees the allocated memory and (old or unused) pwqs.

As the result, batching multiple apply_workqueue_attrs()s can
succeed or fail as a complete unit:
	1) batch do all the first stage for all the workqueues
	2) only commit all when all the above succeed.

This patch is a preparation for the next patch ("Allow modifying low level
unbound workqueue cpumask") which will do a multiple apply_workqueue_attrs().

The patch doesn't have functionality changed except two minor adjustment:
	1) free_unbound_pwq() for the error path is removed, we use the
	   heavier version put_pwq_unlocked() instead since the error path
	   is rare. this adjustment simplifies the code.
	2) the memory-allocation is also moved into wq_pool_mutex.
	   this is needed to avoid to do the further splitting.

tj: minor updates to comments.

Suggested-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-04-27 11:13:40 -04:00
Paolo Bonzini 73459e2a1a x86: pvclock: Really remove the sched notifier for cross-cpu migrations
This reverts commits 0a4e6be9ca
and 80f7fdb1c7.

The task migration notifier was originally introduced in order to support
the pvclock vsyscall with non-synchronized TSC, but KVM only supports it
with synchronized TSC.  Hence, on KVM the race condition is only needed
due to a bad implementation on the host side, and even then it's so rare
that it's mostly theoretical.

As far as KVM is concerned it's possible to fix the host, avoiding the
additional complexity in the vDSO and the (re)introduction of the task
migration notifier.

Xen, on the other hand, hasn't yet implemented vsyscall support at
all, so we do not care about its plans for non-synchronized TSC.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-04-27 15:49:30 +02:00
Linus Torvalds 9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Viresh Kumar 149aabcc44 clockevents: Shutdown detached clockevent device
A clockevent device is marked DETACHED when it is replaced by another
clockevent device.

The device is shutdown properly for drivers that implement legacy
->set_mode() callback, as we call ->set_mode() for CLOCK_EVT_MODE_UNUSED
as well.

But for the new per-state callback interface, we skip shutting down the
device, as we thought its an internal state change. That wasn't correct.

The effect is that the device is left programmed in oneshot or periodic
mode.

Fall-back to 'case CLOCK_EVT_STATE_SHUTDOWN', to shutdown the device.

Fixes: bd624d75db "clockevents: Introduce mode specific callbacks"
Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/eef0a91c51b74d4e52c8e5a95eca27b5a0563f07.1428650683.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-24 21:01:48 +02:00
Roger Quadros 10a50f1ab5 genirq: Set IRQCHIP_SKIP_SET_WAKE flag for dummy_irq_chip
Without this system suspend is broken on systems that have
drivers calling enable/disable_irq_wake() for interrupts based off
the dummy irq hook. (e.g. drivers/gpio/gpio-pcf857x.c)

Signed-off-by: Roger Quadros <rogerq@ti.com>
Cc: <cw00.choi@samsung.com>
Cc: <balbi@ti.com>
Cc: <tony@atomide.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Link: http://lkml.kernel.org/r/552E1DD3.4040106@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-24 20:57:06 +02:00
Chen Hanxiao d0f702e648 cgroup: fix some comment typos
s/effctive/effective
s/hierarhcy/hierarchy
s/shoulid/should

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-04-23 11:09:36 -04:00
Martin Schwidefsky 7e01b5acd8 kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP
Introduce KEXEC_CONTROL_MEMORY_GFP to allow the architecture code
to override the gfp flags of the allocation for the kexec control
page. The loop in kimage_alloc_normal_control_pages allocates pages
with GFP_KERNEL until a page is found that happens to have an
address smaller than the KEXEC_CONTROL_MEMORY_LIMIT. On systems
with a large memory size but a small KEXEC_CONTROL_MEMORY_LIMIT
the loop will keep allocating memory until the oom killer steps in.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-04-23 16:52:01 +02:00
Thomas Gleixner b484403b9a sched: debug: Remove the cfs bandwidth timer_active printout
The struct member is gone.

Reported-by: fengguang.wu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
2015-04-23 13:58:09 +02:00
Linus Torvalds 27cf3a16b2 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
 "Seven audit patches for v4.1, all bug fixes.

  The largest, and perhaps most significant commit helps resolve some
  memory pressure issues related to the inode cache and audit, there are
  also a few small commits which help resolve some timing issues with
  the audit log queue, and the rest fall into the always popular "code
  clean-up" category.

  In general, nothing really substantial, just a nice set of maintenance
  patches"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: Remove condition which always evaluates to false
  audit: reduce mmap_sem hold for mm->exe_file
  audit: consolidate handling of mm->exe_file
  audit: code clean up
  audit: don't reset working wait time accidentally with auditd
  audit: don't lose set wait time on first successful call to audit_log_start()
  audit: move the tree pruning to a dedicated thread
2015-04-22 14:49:23 -07:00
kbuild test robot 9183034879 perf: perf_mux_hrtimer_cancel() can be static
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: kbuild-all@01.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150422200000.GA122603@lkp-sb04
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 22:06:34 +02:00
Linus Torvalds 4f2112351b This adds three fixes for the tracing code.
The first is a bug when ftrace_dump_on_oops is triggered in atomic context
 and function graph tracer is the tracer that is being reported.
 
 The second fix is bad parsing of the trace_events from the kernel
 command line, where it would ignore specific events if the system
 name is used with defining the event(it enables all events within the
 system).
 
 The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was missing
 to see if the ptr was incremented to the end of the string, but the loop
 increments it again and can miss the nul delimiter to stop processing.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJVN7g7AAoJEEjnJuOKh9ldLCkIAJj6wsj59wR8aIxtxnD5bJZZ
 Y9dKkas6BOaUCGp0MVBCkpm3uMgh0uPO10jOuthgc3LgQy0piwKJrIzGkI5gcRuA
 JvZw2X08/jCSNu8BHydes2A0XMkZobMuWFAeWz3CSzNBfbI3sDDqgnRQ9eyMM66R
 +sPV7ZELQLK/ZFs93gFoaZe/OKGYJcamhMtG2v7p9h1qBJZUDakRFo478bAwu5SB
 Kh6xpXA76WnmkeQekAAsWGdqIQzoNy3IoVePmdhVpZvoiKLUrf1JWVYFoNkO39Ik
 kC1gqJro0EmHQFOo5rt8yQmqXjvSU0sS/sAW3HZ0Szl5OtiUNnag+Wt3ku7lr8U=
 =VORa
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This adds three fixes for the tracing code.

  The first is a bug when ftrace_dump_on_oops is triggered in atomic
  context and function graph tracer is the tracer that is being
  reported.

  The second fix is bad parsing of the trace_events from the kernel
  command line, where it would ignore specific events if the system name
  is used with defining the event(it enables all events within the
  system).

  The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was
  missing to see if the ptr was incremented to the end of the string,
  but the loop increments it again and can miss the nul delimiter to
  stop processing"

* tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix possible out of bounds memory access when parsing enums
  tracing: Fix incorrect enabling of trace events by boot cmdline
  tracing: Handle ftrace_dump() atomic context in graph_trace_open()
2015-04-22 11:27:36 -07:00
Linus Torvalds 15ce2658dd Quentin opened a can of worms by adding extable entry checking to modpost,
but most architectures seem fixed now.  Thanks to all involved.
 
 Last minute rebase because I noticed a "[PATCH]" had snuck into a commit
 message somehow.
 
 Cheers,
 Rusty.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJVN1X3AAoJENkgDmzRrbjxmBEP/1Kv1wCrUGg07TfqNTJgr5Pe
 R81C+8P2wSEsA94lBhLNbn2DsN7uWsygcSXZMQ+5CrmbKAG45kRlMUzSlg6IdGXo
 usA9rOlH4hR+Dqn3zyx543xMJyp0a0LoSCLWGMmr/U71AXNp5kehvbIv64gJHrwg
 4CALI9qCwHH4FXF7WBYdLknlfpmD7KzCjIVckkfUfwf2A8mZXKdqBFQ+MPqbChEm
 vpFWkgp1oJgK4OcvvBeiNT2PwFZy1vmJtQWc2lieJ6HCjbqvwgM0g3EYTIQmccIm
 O40mEFMNkUuliMtrCZgOJBP2bmWy79JydiUq5Mu5Cb4bL6jGl2r6Z+w+iQ7Sggv9
 DTqTrk0/Cn02krJXDXAHVOXXgTqggf1xev6wr+3dbZn5sytQ8ddImuuVai8KALoC
 aEXAsnAK+3GnkAn9qqKVFhnrnCcI69I6srUAn5DKVWu36+Ye05FsZboIFYcxcK1F
 NZ+31xA17xA+yoo62ly/Auz7DXMa2QZfJcoQLMx2fMgL/+wMqzfGbcrZ5ZaVIj4w
 ePig1SbozAweAAfX7+W+QCQ3wqNN/nJgMO8vPldlcq7eaXH0/Dqu72cC2d82dK+H
 xl/1pEj83W0AkUkfNS8j3Z4zSzg31g8bK5SmPPRID00mx8roCfsP/Cfx5hRiO8U2
 ECtbKDxSyUWwF9vnOLVR
 =EYrW
 -----END PGP SIGNATURE-----

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "Quentin opened a can of worms by adding extable entry checking to
  modpost, but most architectures seem fixed now.  Thanks to all
  involved.

  Last minute rebase because I noticed a "[PATCH]" had snuck into a
  commit message somehow"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modpost: don't emit section mismatch warnings for compiler optimizations
  modpost: expand pattern matching to support substring matches
  modpost: do not try to match the SHT_NUL section.
  modpost: fix extable entry size calculation.
  modpost: fix inverted logic in is_extable_fault_address().
  modpost: handle -ffunction-sections
  modpost: Whitelist .text.fixup and .exception.text
  params: handle quotes properly for values not of form foo="bar".
  modpost: document the use of struct section_check.
  modpost: handle relocations mismatch in __ex_table.
  scripts: add check_extable.sh script.
  modpost: mismatch_handler: retrieve tosym information only when needed.
  modpost: factorize symbol pretty print in get_pretty_name().
  modpost: add handler function pointer to sectioncheck.
  modpost: add .sched.text and .kprobes.text to the TEXT_SECTIONS list.
  modpost: add strict white-listing when referencing sections.
  module: do not print allocation-fail warning on bogus user buffer size
  kernel/module.c: fix typos in message about unused symbols
2015-04-22 09:49:24 -07:00
Peter Zijlstra 272325c482 perf: Fix mux_interval hrtimer wreckage
Thomas stumbled over the hrtimer_forward_now() in
perf_event_mux_interval_ms_store() and noticed its broken-ness.

You cannot just change the expiry time of an active timer, it will
destroy the red-black tree order and cause havoc.

Change it to (re)start the timer instead, (re)starting a timer will
dequeue and enqueue a timer and therefore preserve rb-tree order.

Since we cannot enqueue remotely, wrap the thing in
cpu_function_call(), this however mandates that we restrict ourselves
to online cpus. Also serialize the entire setting so we don't get
multiple concurrent threads trying to update to different values.

Also fix a problem in perf_mux_hrtimer_restart(), checking against
hrtimer_active() can actually loose us the timer when timer->state ==
HRTIMER_STATE_CALLBACK and the callback has already decided NORESTART.

Furthermore it doesn't make any sense to test
hrtimer_callback_running() when we already tested hrtimer_active(),
but with the above change, we explicitly must call it when
callback_running.

Lastly, rename a few functions:

  s/perf_cpu_hrtimer_/perf_mux_hrtimer_/ -- because I could not find
                                            the mux timer function

  s/\<hr\>/timer/ -- because that's the normal way of calling things.

Fixes: 62b8563979 ("perf: Add sysfs entry to adjust multiplexing interval per PMU")
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150415095011.863052571@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:12:22 +02:00
Peter Zijlstra 77a4d1a1b9 sched: Cleanup bandwidth timers
Roman reported a 3 cpu lockup scenario involving __start_cfs_bandwidth().

The more I look at that code the more I'm convinced its crack, that
entire __start_cfs_bandwidth() thing is brain melting, we don't need to
cancel a timer before starting it, *hrtimer_start*() will happily remove
the timer for you if its still enqueued.

Removing that, removes a big part of the problem, no more ugly cancel
loop to get stuck in.

So now, if I understand things right, the entire reason you have this
cfs_b->lock guarded ->timer_active nonsense is to make sure we don't
accidentally lose the timer.

It appears to me that it should be possible to guarantee that same by
unconditionally (re)starting the timer when !queued. Because regardless
what hrtimer::function will return, if we beat it to (re)enqueue the
timer, it doesn't matter.

Now, because hrtimers don't come with any serialization guarantees we
must ensure both handler and (re)start loop serialize their access to
the hrtimer to avoid both trying to forward the timer at the same
time.

Update the rt bandwidth timer to match.

This effectively reverts: 09dc4ab039 ("sched/fair: Fix
tg_set_cfs_bandwidth() deadlock on rq->lock").

Reported-by: Roman Gushchin <klamm@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20150415095011.804589208@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:53 +02:00
Peter Zijlstra 5de2755c8c hrtimer: Allow concurrent hrtimer_start() for self restarting timers
Because we drop cpu_base->lock around calling hrtimer::function, it is
possible for hrtimer_start() to come in between and enqueue the timer.

If hrtimer::function then returns HRTIMER_RESTART we'll hit the BUG_ON
because HRTIMER_STATE_ENQUEUED will be set.

Since the above is a perfectly valid scenario, remove the BUG_ON and
make the enqueue_hrtimer() call conditional on the timer not being
enqueued already.

NOTE: in that concurrent scenario its entirely common for both sites
to want to modify the hrtimer, since hrtimers don't provide
serialization themselves be sure to provide some such that the
hrtimer::function and the hrtimer_start() caller don't both try and
fudge the expiration state at the same time.

To that effect, add a WARN when someone tries to forward an already
enqueued timer, the most common way to change the expiry of self
restarting timers. Ideally we'd put the WARN in everything modifying
the expiry but most of that is inlines and we don't need the bloat.

Fixes: 2d44ae4d71 ("hrtimer: clean up cpu->base locking tricks")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20150415113105.GT5029@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner 2ad5d3272d timer: Put usleep_range into the __sched section
do_usleep_range() and schedule_hrtimeout_range() are __sched as
well. So it makes no sense to have the exported function in a
different section.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203503.833709502@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner 6deba083e1 timer: Remove pointless return value of do_usleep_range()
The only user ignores it anyway and rightfully so.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203503.756060258@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner 19d9f4225d hrtimer: Avoid locking in hrtimer_cancel() if timer not active
We can do a lockless check for hrtimer_active before actually taking
the lock in hrtimer[_try_to]_cancel. This is useful for hotpath users
like nanosleep as they avoid the lock dance when the timer has
expired.

This is safe because active is true when the timer is enqueued or the
callback is running. Taking the hrtimer base lock does not protect
against concurrent hrtimer_start calls, the callsite has to do the
proper serialization itself.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203503.580273114@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner 61699e1307 hrtimer: Remove hrtimer_start() return value
No user was ever interested whether the timer was active or not when
it was started. All abusers of the return value are gone, so get rid
of it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203503.483556394@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner b8a62f1ff0 tick: broadcast-hrtimer: Remove overly clever return value abuse
The assignment of bc_moved in the conditional construct relies on the
fact that in the case of hrtimer_start() invocation the return value
is always 0. It took me a while to understand it.

We want to get rid of the hrtimer_start() return value. Open code the
logic which makes it readable as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203503.404751457@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner b193217e6d alarmtimer: Get rid of unused return value
We want to get rid of the hrtimer_start() return value and the alarm
timer return value is nowhere used. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20150414203503.243910615@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:52 +02:00
Thomas Gleixner ccdd92c17e rtmutex: Remove bogus hrtimer_active() check
The check for hrtimer_active() after starting the timer is
pointless. If the timer is inactive it has expired already and
therefor the task pointer is already NULL.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203503.081830481@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner 2e4b0d3fe8 futex: Remove bogus hrtimer_active() check
The check for hrtimer_active() after starting the timer is
pointless. If the timer is inactive it has expired already and
therefor the task pointer is already NULL.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.985825453@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner 3f7b349ac1 hrtimer: Remove bogus hrtimer_active() check
The check for hrtimer_active() after starting the timer is
pointless. If the timer is inactive it has expired already and
therefor the task pointer is already NULL.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.907149271@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner 02a171af1a hrtimer: Make hrtimer_start() a inline wrapper
No point for an extra export just to set the extra argument of
hrtimer_start_range_ns() to 0.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.808544539@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner 58f1f803f1 hrtimer: Get rid of __hrtimer_start_range_ns()
No more callers. Remove the leftovers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.707871492@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner cc9684d3c1 sched: deadline: Use hrtimer_start()
hrtimer_start() does not longer defer already expired timers to the
softirq. Get rid of the __hrtimer_start_range_ns() invocation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.627353666@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner 4961b6e118 sched: core: Use hrtimer_start[_expires]()
hrtimer_start() now enforces a timer interrupt when an already expired
timer is enqueued.

Get rid of the __hrtimer_start_range_ns() invocations and the loops
around it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.531131739@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner 3497d206c4 perf: core: Use hrtimer_start()
hrtimer_start() does not longer defer already expired timers to the
softirq. Get rid of the __hrtimer_start_range_ns() invocation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.452104213@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:51 +02:00
Thomas Gleixner c1ad348b45 tick: Nohz: Rework next timer evaluation
The evaluation of the next timer in the nohz code is based on jiffies
while all the tick internals are nano seconds based. We have also to
convert hrtimer nanoseconds to jiffies in the !highres case. That's
just wrong and introduces interesting corner cases.

Turn it around and convert the next timer wheel timer expiry and the
rcu event to clock monotonic and base all calculations on
nanoseconds. That identifies the case where no timer is pending
clearly with an absolute expiry value of KTIME_MAX.

Makes the code more readable and gets rid of the jiffies magic in the
nohz code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203502.184198593@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner 157d29e101 tick: Sched: Restructure code
Get rid of one indentation level. Preparatory patch for a major
rework. No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203502.101563235@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner 0ff53d0964 tick: sched: Force tick interrupt and get rid of softirq magic
We already got rid of the hrtimer reprogramming loops and hoops as
hrtimer now enforces an interrupt if the enqueued time is in the past.

Do the same for the nohz non highres mode. That gets rid of the need
to raise the softirq which only serves the purpose of getting the
machine out of the inner idle loop.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203502.023464878@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner afc08b15cc tick: sched: Remove hrtimer_active() checks
hrtimer_start() enforces a timer interrupt if the timer is already
expired. Get rid of the checks and the forward loop.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203501.943658239@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner c6eb3f70d4 hrtimer: Get rid of hrtimer softirq
hrtimer softirq is a leftover from the initial implementation and
serves only the purpose to handle the enqueueing of already expired
timers in the high resolution timer mode. We discussed whether we
change the return value and force all start sites to handle that the
timer is already expired, but that would be a Herculean task and I'm
not sure whether its a good idea to enforce that handling on
everyone.

A simpler solution is to enforce a timer interrupt instead of raising
and scheduling a softirq. Just use the existing infrastructure to do
so and remove all the softirq leftovers.

The HRTIMER softirq enum is now unused, but kept around because trace
parsers rely on the existing numbering.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203501.840834708@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner 895bdfa793 hrtimer: Keep pointer to first timer and simplify __remove_hrtimer()
__remove_hrtimer() needs to evaluate the expiry time to figure out
whether the timer which is removed is eventually the first expiring
timer on the cpu. Keep a pointer to it, which is lazily updated, so we
can avoid the evaluation dance and retrieve the information from there.

Generates slightly better code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203501.752838019@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner b97f44c9b6 hrtimer: Make use of timerqueue_add/del return values
Use the return value instead of reevaluating the information.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203501.658152945@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:50 +02:00
Thomas Gleixner 34aee88a02 hrtimer: Use cpu_base->active_base for hotpath iterators
The active_bases field is guaranteed to be in sync with the timerqueue
of the corresponding clock base. So we can use it for iterating over
the clock bases. This allows to break out early if no more active
clock bases are available and avoids touching the cache lines of
inactive clock bases.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203501.322887675@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:49 +02:00
Thomas Gleixner e19ffe8be2 hrtimer: Use bits for various boolean indicators
No point in wasting 12 byte storage space. Generates better code as well.

Text size reduction:
       x8664 -64, i386 -16, ARM -132, ARM64 -0, power64 -48

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203501.227955358@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:49 +02:00
Thomas Gleixner 868a3e915f hrtimer: Make offset update smarter
On every tick/hrtimer interrupt we update the offset variables of the
clock bases. That's silly because these offsets change very seldom.

Add a sequence counter to the time keeping code which keeps track of
the offset updates (clock_was_set()). Have a sequence cache in the
hrtimer cpu bases to evaluate whether the offsets must be updated or
not. This allows us later to avoid pointless cacheline pollution.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20150414203501.132820245@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
2015-04-22 17:06:49 +02:00
Thomas Gleixner 21d6d52a1b hrtimer: Get rid of softirq time
The softirq time field in the clock bases is an optimization from the
early days of hrtimers. It provides a coarse "jiffies" like time
mostly for self rearming timers.

But that comes with a price:
    - Larger code size
    - Extra storage space
    - Duplicated functions with really small differences
   
The benefit of this is optimization is marginal for contemporary
systems.

Consolidate everything on the high resolution timer
implementation. This makes further optimizations possible.

Text size reduction:
       x8664 -95, i386 -356, ARM -148, ARM64 -40, power64 -16

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203501.039977424@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:49 +02:00
Thomas Gleixner a6ffebce7f hrtimer: Make the statistics fields smaller
No point in having usigned long for /proc/timer_list statistics. Make
them unsigned int.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203500.959773467@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:49 +02:00
Thomas Gleixner 056a3cacbc hrtimer: Get rid of hrtimer_get_res()
The resolution is directly accessible now. So its simpler just to fill
in the values of the timespec and be done with it.

Text size reduction (combined with "hrtimer: Get rid of the resolution
field in hrtimer_clock_base"):
       x8664 -61, i386 -221, ARM -60, power64 -48

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203500.879888080@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:49 +02:00
Thomas Gleixner 398ca17fb5 hrtimer: Get rid of the resolution field in hrtimer_clock_base
The field has no value because all clock bases have the same
resolution. The resolution only changes when we switch to high
resolution timer mode. We can evaluate that from a single static
variable as well. In the !HIGHRES case its simply a constant.

Export the variable, so we can simplify the usage sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203500.645454122@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:48 +02:00
Viresh Kumar d9f0acdeef hrtimer: Update active_bases before calling hrtimer_force_reprogram()
'active_bases' indicates which clock-base have active timer. The
intention of this bit field was to avoid evaluating inactive bases. It
was introduced with the introduction of the BOOTTIME and TAI clock
bases, but it was never brought into full use.

We want to use it now, but in __remove_hrtimer() the update happens
after the calling hrtimer_force_reprogram() which has to evaluate all
clock bases for the next expiring timer. So in case the last timer of
a clock base got removed we still see the active bit and therefor
evaluate the clock base for no value. There are further optimizations
possible when active_bases is updated in the right place.

Move the update before the call to hrtimer_force_reprogram()

[ tglx: Massaged changelog ]

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linaro-kernel@lists.linaro.org
Link: http://lkml.kernel.org/r/20150414203500.533438642@linutronix.de
Link: http://lkml.kernel.org/r/c7c8ebcd9ed88bb09d76059c745a1fafb48314e7.1428039899.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:48 +02:00
Thomas Gleixner 91e5a2170e hrtimer: Document hrtimer_forward[_now]() proper
Document the calling context conditions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150413210035.178751779@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 17:06:48 +02:00
Thomas Gleixner 51a03393ba timekeeping: Remove stale function prototype
commit 61edec81d2 "timekeeping: Simplify timekeeping_clocktai()"
implemented timekeeping_clocktai() as an inline function, but left the
old extern prototype in the header file. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 12:03:39 +02:00
Joe Perches 7de4e74430 timer_list: Reduce SEQ_printf footprint
This macro can be converted to a static function to reduce
object size.

(x86-64 defconfig)
$ size kernel/time/timer_list.o*
   text	   data	    bss	    dec	    hex	filename
   6583	      8	      0	   6591	   19bf	kernel/time/timer_list.o.old
   4647	      8	      0	   4655	   122f	kernel/time/timer_list.o.new

Signed-off-by: Joe Perches <joe@perches.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1429295958.2850.104.camel@perches.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 12:03:39 +02:00
Linus Torvalds 1fc149933f Char/Misc driver patches for 4.1-rc1
Here's the big char/misc driver patchset for 4.1-rc1.
 
 Lots of different driver subsystem updates here, nothing major, full
 details are in the shortlog below.
 
 All of this has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlU2IMEACgkQMUfUDdst+yloDQCfbyIRL23WVAn9ckQse/y8gbjB
 OT4AoKTJbwndDP9Kb/lrj2tjd9QjNVrC
 =xhen
 -----END PGP SIGNATURE-----

Merge tag 'char-misc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here's the big char/misc driver patchset for 4.1-rc1.

  Lots of different driver subsystem updates here, nothing major, full
  details are in the shortlog.

  All of this has been in linux-next for a while"

* tag 'char-misc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (133 commits)
  mei: trace: remove unused TRACE_SYSTEM_STRING
  DTS: ARM: OMAP3-N900: Add lis3lv02d support
  Documentation: DT: lis302: update wakeup binding
  lis3lv02d: DT: add wakeup unit 2 and wakeup threshold
  lis3lv02d: DT: use s32 to support negative values
  Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX case
  Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case
  mei: replace check for connection instead of transitioning
  mei: use mei_cl_is_connected consistently
  mei: fix mei_poll operation
  hv_vmbus: Add gradually increased delay for retries in vmbus_post_msg()
  Drivers: hv: hv_balloon: survive ballooning request with num_pages=0
  Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor function
  Drivers: hv: hv_balloon: do not online pages in offline blocks
  hv: remove the per-channel workqueue
  hv: don't schedule new works in vmbus_onoffer()/vmbus_onoffer_rescind()
  hv: run non-blocking message handlers in the dispatch tasklet
  coresight: moving to new "hwtracing" directory
  coresight-tmc: Adding a status interface to sysfs
  coresight: remove the unnecessary configuration coresight-default-sink
  ...
2015-04-21 09:42:58 -07:00
Linus Torvalds 41d5e08ea8 TTY/Serial patches for 4.1-rc1
Here's the big tty/serial driver update for 4.1-rc1.
 
 It was delayed for a bit due to some questions surrounding some of the
 console command line parsing changes that are in here.  There's still
 one tiny regression for people who were previously putting multiple
 console command lines and expecting them all to be ignored for some odd
 reason, but Peter is working on fixing that.  If not, I'll send a revert
 for the offending patch, but I have faith that Peter can address it.
 
 Other than the console work here, there's the usual serial driver
 updates and changes, and a buch of 8250 reworks to try to make that
 driver easier to maintain over time, and have it support more devices in
 the future.
 
 All of these have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlU2IcUACgkQMUfUDdst+ylFqACcC8LPhFEZg9aHn0hNUoqGK3rE
 5dUAnR4b8r/NYqjVoE9FJZgZfB/TqVi1
 =lyN/
 -----END PGP SIGNATURE-----

Merge tag 'tty-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here's the big tty/serial driver update for 4.1-rc1.

  It was delayed for a bit due to some questions surrounding some of the
  console command line parsing changes that are in here.  There's still
  one tiny regression for people who were previously putting multiple
  console command lines and expecting them all to be ignored for some
  odd reason, but Peter is working on fixing that.  If not, I'll send a
  revert for the offending patch, but I have faith that Peter can
  address it.

  Other than the console work here, there's the usual serial driver
  updates and changes, and a buch of 8250 reworks to try to make that
  driver easier to maintain over time, and have it support more devices
  in the future.

  All of these have been in linux-next for a while"

* tag 'tty-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (119 commits)
  n_gsm: Drop unneeded cast on netdev_priv
  sc16is7xx: expose RTS inversion in RS-485 mode
  serial: 8250_pci: port failed after wakeup from S3
  earlycon: 8250: Document kernel command line options
  earlycon: 8250: Fix command line regression
  earlycon: Fix __earlycon_table stride
  tty: clean up the tty time logic a bit
  serial: 8250_dw: only get the clock rate in one place
  serial: 8250_dw: remove useless ACPI ID check
  dmaengine: hsu: move memory allocation to GFP_NOWAIT
  dmaengine: hsu: remove redundant pieces of code
  serial: 8250_pci: add Intel Tangier support
  dmaengine: hsu: add Intel Tangier PCI ID
  serial: 8250_pci: replace switch-case by formula for Intel MID
  serial: 8250_pci: replace switch-case by formula
  tty: cpm_uart: replace CONFIG_8xx by CONFIG_CPM1
  serial: jsm: some off by one bugs
  serial: xuartps: Fix check in console_setup().
  serial: xuartps: Get rid of register access macros.
  serial: xuartps: Fix iobase use.
  ...
2015-04-21 09:33:10 -07:00
Linus Torvalds 5224b9613b smp: Fix error case handling in smp_call_function_*()
Commit 8053871d0f ("smp: Fix smp_call_function_single_async()
locking") fixed the locking for the asynchronous smp-call case, but in
the process of moving the lock handling around, one of the error cases
ended up not unlocking the call data at all.

This went unnoticed on x86, because this is a "caller is buggy" case,
where the caller is trying to call a non-existent CPU.  But apparently
ARM does that (at least under qemu-arm).  Bindly doing cross-cpu calls
to random CPU's that aren't even online seems a bit fishy, but the error
handling was clearly not correct.

Simply add the missing "csd_unlock()" to the error path.

Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Analyzed-by: Rabin Vincent <rabin@rab.in>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-19 13:19:23 -07:00
Linus Torvalds 396c9df223 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Two fixes: an smp-call fix and a lockdep fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Fix smp_call_function_single_async() locking
  lockdep: Make print_lock() robust against concurrent release
2015-04-18 11:23:42 -04:00
Ingo Molnar cb0f3f320d Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent
Pull RCU fix from Paul E. McKenney:

 "This series contains a single change that fixes Kconfig asking pointless
  questions."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-18 14:49:41 +02:00
Linus Torvalds 388f997620 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix verifier memory corruption and other bugs in BPF layer, from
    Alexei Starovoitov.

 2) Add a conservative fix for doing BPF properly in the BPF classifier
    of the packet scheduler on ingress.  Also from Alexei.

 3) The SKB scrubber should not clear out the packet MARK and security
    label, from Herbert Xu.

 4) Fix oops on rmmod in stmmac driver, from Bryan O'Donoghue.

 5) Pause handling is not correct in the stmmac driver because it
    doesn't take into consideration the RX and TX fifo sizes.  From
    Vince Bridgers.

 6) Failure path missing unlock in FOU driver, from Wang Cong.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
  net: dsa: use DEVICE_ATTR_RW to declare temp1_max
  netns: remove BUG_ONs from net_generic()
  IB/ipoib: Fix ndo_get_iflink
  sfc: Fix memcpy() with const destination compiler warning.
  altera tse: Fix network-delays and -retransmissions after high throughput.
  net: remove unused 'dev' argument from netif_needs_gso()
  act_mirred: Fix bogus header when redirecting from VLAN
  inet_diag: fix access to tcp cc information
  tcp: tcp_get_info() should fetch socket fields once
  net: dsa: mv88e6xxx: Add missing initialization in mv88e6xxx_set_port_state()
  skbuff: Do not scrub skb mark within the same name space
  Revert "net: Reset secmark when scrubbing packet"
  bpf: fix two bugs in verification logic when accessing 'ctx' pointer
  bpf: fix bpf helpers to use skb->mac_header relative offsets
  stmmac: Configure Flow Control to work correctly based on rxfifo size
  stmmac: Enable unicast pause frame detect in GMAC Register 6
  stmmac: Read tx-fifo-depth and rx-fifo-depth from the devicetree
  stmmac: Add defines and documentation for enabling flow control
  stmmac: Add properties for transmit and receive fifo sizes
  stmmac: fix oops on rmmod after assigning ip addr
  ...
2015-04-17 16:31:08 -04:00
Steven Rostedt (Red Hat) 3193899d4d tracing: Fix possible out of bounds memory access when parsing enums
The code that replaces the enum names with the enum values in the
tracepoints' format files could possible miss the end of string nul
character. This was caused by processing things like backslashes, quotes
and other tokens. After processing the tokens, a check for the nul
character needed to be done before continuing the loop, because the loop
incremented the pointer before doing the check, which could bypass the nul
character.

Link: http://lkml.kernel.org/r/552E661D.5060502@oracle.com

Reported-by: Sasha Levin <sasha.levin@oracle.com> # via KASan
Tested-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Fixes: 0c564a538a "tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-17 10:34:43 -04:00
Davidlohr Bueso 11163348a2 oprofile: reduce mmap_sem hold for mm->exe_file
sync_buffer() needs the mmap_sem for two distinct operations, both only
occurring upon user context switch handling:

 1) Dealing with the exe_file.

 2) Adding the dcookie data as we need to lookup the vma that
   backs it. This is done via add_sample() and add_data().

This patch isolates 1), for it will no longer need the mmap_sem for
serialization.  However, for now, make of the more standard
get_mm_exe_file(), requiring only holding the mmap_sem to read the value,
and relying on reference counting to make sure that the exe file won't
dissappear underneath us while doing the get dcookie.

As a consequence, for 2) we move the mmap_sem locking into where we really
need it, in lookup_dcookie().  The benefits are twofold: reduce mmap_sem
hold times, and cleaner code.

[akpm@linux-foundation.org: export get_mm_exe_file for arch/x86/oprofile/oprofile.ko]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Robert Richter <rric@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:11 -04:00
Andrey Ryabinin 9d796e6623 gcov: fix softlockups
gcov profiling if enabled with other heavy compile-time instrumentation
like KASan could trigger following softlockups:

  NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
  Modules linked in:
  irq event stamp: 22823276
  hardirqs last  enabled at (22823275): [<ffffffff86e8d10d>] mutex_lock_nested+0x7d9/0x930
  hardirqs last disabled at (22823276): [<ffffffff86e9521d>] apic_timer_interrupt+0x6d/0x80
  softirqs last  enabled at (22823172): [<ffffffff811ed969>] __do_softirq+0x4db/0x729
  softirqs last disabled at (22823167): [<ffffffff811edfcf>] irq_exit+0x7d/0x15b
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W       3.19.0-05245-gbb33326-dirty #3
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
  task: ffff88006cba8000 ti: ffff88006cbb0000 task.ti: ffff88006cbb0000
  RIP: kasan_mem_to_shadow+0x1e/0x1f
  Call Trace:
    strcmp+0x28/0x70
    get_node_by_name+0x66/0x99
    gcov_event+0x4f/0x69e
    gcov_enable_events+0x54/0x7b
    gcov_fs_init+0xf8/0x134
    do_one_initcall+0x1b2/0x288
    kernel_init_freeable+0x467/0x580
    kernel_init+0x15/0x18b
    ret_from_fork+0x7c/0xb0
  Kernel panic - not syncing: softlockup: hung tasks

Fix this by sticking cond_resched() in gcov_enable_events().

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:08 -04:00
Heinrich Schuchardt 230633d109 kernel/sysctl.c: detect overflows when converting to int
When converting unsigned long to int overflows may occur.  These currently
are not detected when writing to the sysctl file system.

E.g. on a system where int has 32 bits and long has 64 bits
  echo 0x800001234 > /proc/sys/kernel/threads-max
has the same effect as
  echo 0x1234 > /proc/sys/kernel/threads-max

The patch adds the missing check in do_proc_dointvec_conv.

With the patch an overflow will result in an error EINVAL when writing to
the the sysctl file system.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:08 -04:00
Davidlohr Bueso 6e399cd144 prctl: avoid using mmap_sem for exe_file serialization
Oleg cleverly suggested using xchg() to set the new mm->exe_file instead
of calling set_mm_exe_file() which requires some form of serialization --
mmap_sem in this case.  For archs that do not have atomic rmw instructions
we still fallback to a spinlock alternative, so this should always be
safe.  As such, we only need the mmap_sem for looking up the backing
vm_file, which can be done sharing the lock.  Naturally, this means we
need to manually deal with both the new and old file reference counting,
and we need not worry about the MMF_EXE_FILE_CHANGED bits, which can
probably be deleted in the future anyway.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:07 -04:00
Konstantin Khlebnikov 90f31d0ea8 mm: rcu-protected get_mm_exe_file()
This patch removes mm->mmap_sem from mm->exe_file read side.
Also it kills dup_mm_exe_file() and moves exe_file duplication into
dup_mmap() where both mmap_sems are locked.

[akpm@linux-foundation.org: fix comment typo]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt 16db3d3f11 kernel/sysctl.c: threads-max observe limits
Users can change the maximum number of threads by writing to
/proc/sys/kernel/threads-max.

With the patch the value entered is checked against the same limits that
apply when fork_init is called.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt ac1b398de1 kernel/fork.c: avoid division by zero
PAGE_SIZE is not guaranteed to be equal to or less than 8 times the
THREAD_SIZE.

E.g.  architecture hexagon may have page size 1M and thread size 4096.
This would lead to a division by zero in the calculation of max_threads.

With 32-bit calculation there is no solution which delivers valid results
for all possible combinations of the parameters.  The code is only called
once.  Hence a 64-bit calculation can be used as solution.

[akpm@linux-foundation.org: use clamp_t(), per Oleg]
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt ff691f6e03 kernel/fork.c: new function for max_threads
PAGE_SIZE is not guaranteed to be equal to or less than 8 times the
THREAD_SIZE.

E.g.  architecture hexagon may have page size 1M and thread size 4096.
This would lead to a division by zero in the calculation of max_threads.

With this patch the buggy code is moved to a separate function
set_max_threads.  The error is not fixed.

After fixing the problem in a separate patch the new function can be
reused to adjust max_threads after adding or removing memory.

Argument mempages of function fork_init() is removed as totalram_pages is
an exported symbol.

The creation of separate patches for refactoring to a new function and for
fixing the logic was suggested by Ingo Molnar.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Jean Delvare 3ea7f5e25e fork_init: update max_threads comment
The comment explaining what value max_threads is set to is outdated.  The
maximum memory consumption ratio for thread structures was 1/2 until
February 2002, then it was briefly changed to 1/16 before being set to 1/8
which we still use today.  The comment was never updated to reflect that
change, it's about time.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Michal Hocko 35f71bc0a0 fork: report pid reservation failure properly
copy_process will report any failure in alloc_pid as ENOMEM currently
which is misleading because the pid allocation might fail not only when
the memory is short but also when the pid space is consumed already.

The current man page even mentions this case:

: EAGAIN
:
:       A system-imposed limit on the number of threads was encountered.
:       There are a number of limits that may trigger this error: the
:       RLIMIT_NPROC soft resource limit (set via setrlimit(2)), which
:       limits the number of processes and threads for a real user ID, was
:       reached; the kernel's system-wide limit on the number of processes
:       and threads, /proc/sys/kernel/threads-max, was reached (see
:       proc(5)); or the maximum number of PIDs, /proc/sys/kernel/pid_max,
:       was reached (see proc(5)).

so the current behavior is also incorrect wrt.  documentation.  POSIX man
page also suggest returing EAGAIN when the process count limit is reached.

This patch simply propagates error code from alloc_pid and makes sure we
return -EAGAIN due to reservation failure.  This will make behavior of
fork closer to both our documentation and POSIX.

alloc_pid might alsoo fail when the reaper in the pid namespace is dead
(the namespace basically disallows all new processes) and there is no
good error code which would match documented ones. We have traditionally
returned ENOMEM for this case which is misleading as well but as per
Eric W. Biederman this behavior is documented in man pid_namespaces(7)

: If the "init" process of a PID namespace terminates, the kernel
: terminates all of the processes in the namespace via a SIGKILL signal.
: This behavior reflects the fact that the "init" process is essential for
: the correct operation of a PID namespace.  In this case, a subsequent
: fork(2) into this PID namespace will fail with the error ENOMEM; it is
: not possible to create a new processes in a PID namespace whose "init"
: process has terminated.

and introducing a new error code would be too risky so let's stick to
ENOMEM for this case.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Vladimir Davydov 69828dce7a signal: remove warning about using SI_TKILL in rt_[tg]sigqueueinfo
Sending SI_TKILL from rt_[tg]sigqueueinfo was deprecated, so now we issue
a warning on the first attempt of doing it.  We use WARN_ON_ONCE, which is
not informative and, what is worse, taints the kernel, making the trinity
syscall fuzzer complain false-positively from time to time.

It does not look like we need this warning at all, because the behaviour
changed quite a long time ago (2.6.39), and if an application relies on
the old API, it gets EPERM anyway and can issue a warning by itself.

So let us zap the warning in kernel.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Oleg Nesterov 64a4096c5c ptrace: ptrace_detach() can no longer race with SIGKILL
ptrace_detach() re-checks ->ptrace under tasklist lock and calls
release_task() if __ptrace_detach() returns true.  This was needed because
the __TASK_TRACED tracee could be killed/untraced, and it could even pass
exit_notify() before we take tasklist_lock.

But this is no longer possible after 9899d11f65 "ptrace: ensure
arch_ptrace/ptrace_request can never race with SIGKILL".  We can turn
these checks into WARN_ON() and remove release_task().

While at it, document the setting of child->exit_code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Labath <labath@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Oleg Nesterov b72c186999 ptrace: fix race between ptrace_resume() and wait_task_stopped()
ptrace_resume() is called when the tracee is still __TASK_TRACED.  We set
tracee->exit_code and then wake_up_state() changes tracee->state.  If the
tracer's sub-thread does wait() in between, task_stopped_code(ptrace => T)
wrongly looks like another report from tracee.

This confuses debugger, and since wait_task_stopped() clears ->exit_code
the tracee can miss a signal.

Test-case:

	#include <stdio.h>
	#include <unistd.h>
	#include <sys/wait.h>
	#include <sys/ptrace.h>
	#include <pthread.h>
	#include <assert.h>

	int pid;

	void *waiter(void *arg)
	{
		int stat;

		for (;;) {
			assert(pid == wait(&stat));
			assert(WIFSTOPPED(stat));
			if (WSTOPSIG(stat) == SIGHUP)
				continue;

			assert(WSTOPSIG(stat) == SIGCONT);
			printf("ERR! extra/wrong report:%x\n", stat);
		}
	}

	int main(void)
	{
		pthread_t thread;

		pid = fork();
		if (!pid) {
			assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);
			for (;;)
				kill(getpid(), SIGHUP);
		}

		assert(pthread_create(&thread, NULL, waiter, NULL) == 0);

		for (;;)
			ptrace(PTRACE_CONT, pid, 0, SIGCONT);

		return 0;
	}

Note for stable: the bug is very old, but without 9899d11f65 "ptrace:
ensure arch_ptrace/ptrace_request can never race with SIGKILL" the fix
should use lock_task_sighand(child).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Pavel Labath <labath@google.com>
Tested-by: Pavel Labath <labath@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Linus Torvalds 8053871d0f smp: Fix smp_call_function_single_async() locking
The current smp_function_call code suffers a number of problems, most
notably smp_call_function_single_async() is broken.

The problem is that flush_smp_call_function_queue() does csd_unlock()
_after_ calling csd->func(). This means that a caller cannot properly
synchronize the csd usage as it has to.

Change the code to release the csd before calling ->func() for the
async case, and put a WARN_ON_ONCE(csd->flags & CSD_FLAG_LOCK) in
smp_call_function_single_async() to warn us of improper serialization,
because any waiting there can results in deadlocks when called with
IRQs disabled.

Rename the (currently) unused WAIT flag to SYNCHRONOUS and (re)use it
such that we know what to do in flush_smp_call_function_queue().

Rework csd_{,un}lock() to use smp_load_acquire() / smp_store_release()
to avoid some full barriers while more clearly providing lock
semantics.

Finally move the csd maintenance out of generic_exec_single() into its
callers for clearer code.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ Added changelog. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rafael David Tinoco <inaddy@ubuntu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/CA+55aFz492bzLFhdbKN-Hygjcreup7CjMEYk3nTSfRWjppz-OA@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-17 09:57:52 +02:00
Peter Zijlstra d7bc3197b4 lockdep: Make print_lock() robust against concurrent release
During sysrq's show-held-locks command it is possible that
hlock_class() returns NULL for a given lock. The result is then (after
the warning):

	|BUG: unable to handle kernel NULL pointer dereference at 0000001c
	|IP: [<c1088145>] get_usage_chars+0x5/0x100
	|Call Trace:
	| [<c1088263>] print_lock_name+0x23/0x60
	| [<c1576b57>] print_lock+0x5d/0x7e
	| [<c1088314>] lockdep_print_held_locks+0x74/0xe0
	| [<c1088652>] debug_show_all_locks+0x132/0x1b0
	| [<c1315c48>] sysrq_handle_showlocks+0x8/0x10

This *might* happen because the thread on the other CPU drops the lock
after we are looking ->lockdep_depth and ->held_locks points no longer
to a lock that is held.

The fix here is to simply ignore it and continue.

Reported-by: Andreas Messerschmid <andreas@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-17 09:42:14 +02:00
Alexei Starovoitov 725f9dcd58 bpf: fix two bugs in verification logic when accessing 'ctx' pointer
1.
first bug is a silly mistake. It broke tracing examples and prevented
simple bpf programs from loading.

In the following code:
if (insn->imm == 0 && BPF_SIZE(insn->code) == BPF_W) {
} else if (...) {
  // this part should have been executed when
  // insn->code == BPF_W and insn->imm != 0
}

Obviously it's not doing that. So simple instructions like:
r2 = *(u64 *)(r1 + 8)
will be rejected. Note the comments in the code around these branches
were and still valid and indicate the true intent.

Replace it with:
if (BPF_SIZE(insn->code) != BPF_W)
  continue;

if (insn->imm == 0) {
} else if (...) {
  // now this code will be executed when
  // insn->code == BPF_W and insn->imm != 0
}

2.
second bug is more subtle.
If malicious code is using the same dest register as source register,
the checks designed to prevent the same instruction to be used with different
pointer types will fail to trigger, since we were assigning src_reg_type
when it was already overwritten by check_mem_access().
The fix is trivial. Just move line:
src_reg_type = regs[insn->src_reg].type;
before check_mem_access().
Add new 'access skb fields bad4' test to check this case.

Fixes: 9bac3d6d54 ("bpf: allow extended BPF programs access skb fields")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-16 14:08:49 -04:00
Alexei Starovoitov c3de6317d7 bpf: fix verifier memory corruption
Due to missing bounds check the DAG pass of the BPF verifier can corrupt
the memory which can cause random crashes during program loading:

[8.449451] BUG: unable to handle kernel paging request at ffffffffffffffff
[8.451293] IP: [<ffffffff811de33d>] kmem_cache_alloc_trace+0x8d/0x2f0
[8.452329] Oops: 0000 [#1] SMP
[8.452329] Call Trace:
[8.452329]  [<ffffffff8116cc82>] bpf_check+0x852/0x2000
[8.452329]  [<ffffffff8116b7e4>] bpf_prog_load+0x1e4/0x310
[8.452329]  [<ffffffff811b190f>] ? might_fault+0x5f/0xb0
[8.452329]  [<ffffffff8116c206>] SyS_bpf+0x806/0xa30

Fixes: f1bca824da ("bpf: add search pruning optimization to verifier")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-16 12:06:11 -04:00
Joonsoo Kim 84fce9db4d tracing: Fix incorrect enabling of trace events by boot cmdline
There is a problem that trace events are not properly enabled with
boot cmdline. The problem is that if we pass "trace_event=kmem:mm_page_alloc"
to the boot cmdline, it enables all kmem trace events, and not just
the page_alloc event.

This is caused by the parsing mechanism. When we parse the cmdline, the buffer
contents is modified due to tokenization. And, if we use this buffer
again, we will get the wrong result.

Unfortunately, this buffer is be accessed three times to set trace events
properly at boot time. So, we need to handle this situation.

There is already code handling ",", but we need another for ":".
This patch adds it.

Link: http://lkml.kernel.org/r/1429159484-22977-1-git-send-email-iamjoonsoo.kim@lge.com

Cc: stable@vger.kernel.org # 3.19+
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
[ added missing return ret; ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-16 09:44:07 -04:00
Rabin Vincent ef99b88b16 tracing: Handle ftrace_dump() atomic context in graph_trace_open()
graph_trace_open() can be called in atomic context from ftrace_dump().
Use GFP_ATOMIC for the memory allocations when that's the case, in order
to avoid the following splat.

 BUG: sleeping function called from invalid context at mm/slab.c:2849
 in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
 Backtrace:
 ..
 [<8004dc94>] (__might_sleep) from [<801371f4>] (kmem_cache_alloc_trace+0x160/0x238)
  r7:87800040 r6:000080d0 r5:810d16e8 r4:000080d0
 [<80137094>] (kmem_cache_alloc_trace) from [<800cbd60>] (graph_trace_open+0x30/0xd0)
  r10:00000100 r9:809171a8 r8:00008e28 r7:810d16f0 r6:00000001 r5:810d16e8
  r4:810d16f0
 [<800cbd30>] (graph_trace_open) from [<800c79c4>] (trace_init_global_iter+0x50/0x9c)
  r8:00008e28 r7:808c853c r6:00000001 r5:810d16e8 r4:810d16f0 r3:800cbd30
 [<800c7974>] (trace_init_global_iter) from [<800c7aa0>] (ftrace_dump+0x90/0x2ec)
  r4:810d2580 r3:00000000
 [<800c7a10>] (ftrace_dump) from [<80414b2c>] (sysrq_ftrace_dump+0x1c/0x20)
  r10:00000100 r9:809171a8 r8:808f6e7c r7:00000001 r6:00000007 r5:0000007a
  r4:808d5394
 [<80414b10>] (sysrq_ftrace_dump) from [<800169b8>] (return_to_handler+0x0/0x18)
 [<80415498>] (__handle_sysrq) from [<800169b8>] (return_to_handler+0x0/0x18)
  r8:808c8100 r7:808c8444 r6:00000101 r5:00000010 r4:84eb3210
 [<80415668>] (handle_sysrq) from [<800169b8>] (return_to_handler+0x0/0x18)
 [<8042a760>] (pl011_int) from [<800169b8>] (return_to_handler+0x0/0x18)
  r10:809171bc r9:809171a8 r8:00000001 r7:00000026 r6:808c6000 r5:84f01e60
  r4:8454fe00
 [<8007782c>] (handle_irq_event_percpu) from [<80077b44>] (handle_irq_event+0x4c/0x6c)
  r10:808c7ef0 r9:87283e00 r8:00000001 r7:00000000 r6:8454fe00 r5:84f01e60
  r4:84f01e00
 [<80077af8>] (handle_irq_event) from [<8007aa28>] (handle_fasteoi_irq+0xf0/0x1ac)
  r6:808f52a4 r5:84f01e60 r4:84f01e00 r3:00000000
 [<8007a938>] (handle_fasteoi_irq) from [<80076dc0>] (generic_handle_irq+0x3c/0x4c)
  r6:00000026 r5:00000000 r4:00000026 r3:8007a938
 [<80076d84>] (generic_handle_irq) from [<80077128>] (__handle_domain_irq+0x8c/0xfc)
  r4:808c1e38 r3:0000002e
 [<8007709c>] (__handle_domain_irq) from [<800087b8>] (gic_handle_irq+0x34/0x6c)
  r10:80917748 r9:00000001 r8:88802100 r7:808c7ef0 r6:808c8fb0 r5:00000015
  r4:8880210c r3:808c7ef0
 [<80008784>] (gic_handle_irq) from [<80014044>] (__irq_svc+0x44/0x7c)

Link: http://lkml.kernel.org/r/1428953721-31349-1-git-send-email-rabin@rab.in
Link: http://lkml.kernel.org/r/1428957012-2319-1-git-send-email-rabin@rab.in

Cc: stable@vger.kernel.org # 3.13+
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-16 09:32:17 -04:00
Tobias Klauser 2df8406a43 sched/autogroup: Remove unnecessary #ifdef guards
Since commit:

  029632fbb7 ("sched: Make separate sched*.c translation units")

autogroup is a separate translation unit built from the Makefile and
thus no longer needs its content wrapped with #ifdef CONFIG_SCHED_AUTOGROUP.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1429116678-17000-1-git-send-email-tklauser@distanz.ch
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-16 09:20:43 +02:00
Linus Torvalds eea3a00264 Merge branch 'akpm' (patches from Andrew)
Merge second patchbomb from Andrew Morton:

 - the rest of MM

 - various misc bits

 - add ability to run /sbin/reboot at reboot time

 - printk/vsprintf changes

 - fiddle with seq_printf() return value

* akpm: (114 commits)
  parisc: remove use of seq_printf return value
  lru_cache: remove use of seq_printf return value
  tracing: remove use of seq_printf return value
  cgroup: remove use of seq_printf return value
  proc: remove use of seq_printf return value
  s390: remove use of seq_printf return value
  cris fasttimer: remove use of seq_printf return value
  cris: remove use of seq_printf return value
  openrisc: remove use of seq_printf return value
  ARM: plat-pxa: remove use of seq_printf return value
  nios2: cpuinfo: remove use of seq_printf return value
  microblaze: mb: remove use of seq_printf return value
  ipc: remove use of seq_printf return value
  rtc: remove use of seq_printf return value
  power: wakeup: remove use of seq_printf return value
  x86: mtrr: if: remove use of seq_printf return value
  linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
  MAINTAINERS: CREDITS: remove Stefano Brivio from B43
  .mailmap: add Ricardo Ribalda
  CREDITS: add Ricardo Ribalda Delgado
  ...
2015-04-15 16:39:15 -07:00
Joe Perches 962e3707d9 tracing: remove use of seq_printf return value
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Miscellanea:

o Remove unused return value from trace_lookup_stack

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:25 -07:00
Joe Perches 94ff212d09 cgroup: remove use of seq_printf return value
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:25 -07:00
Joel Stanley 7a54f46b30 kernel/reboot.c: add orderly_reboot for graceful reboot
The kernel has orderly_poweroff which allows the kernel to initiate a
graceful shutdown of userspace, by running /sbin/poweroff.  This adds
orderly_reboot that will cause userspace to shut itself down by calling
/sbin/reboot.

This will be used for shutdown initiated by a system controller on
platforms that do not use ACPI.

orderly_reboot() should be used when the system wants to allow userspace
to gracefully shut itself down.  For cases where the system may imminently
catch on fire, the existing emergency_restart() provides an immediate
reboot without involving userspace.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:23 -07:00
Aaron Tomlin 972fae6993 kernel/hung_task.c: change hung_task.c to use for_each_process_thread()
In check_hung_uninterruptible_tasks() avoid the use of deprecated
while_each_thread().

The "max_count" logic will prevent a livelock - see commit 0c740d0a
("introduce for_each_thread() to replace the buggy while_each_thread()").
Having said this let's use for_each_process_thread().

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Wysochanski <dwysocha@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:22 -07:00
Jakub Sitnicki 96831c0a67 kernel/resource.c: remove deprecated __check_region() and friends
All users of __check_region(), check_region(), and check_mem_region() are
gone.  We got rid of the last user in v4.0-rc1.  Remove them.

bloat-o-meter on x86_64 shows:

add/remove: 0/3 grow/shrink: 0/0 up/down: 0/-102 (-102)
function                                     old     new   delta
__kstrtab___check_region                      15       -     -15
__ksymtab___check_region                      16       -     -16
__check_region                                71       -     -71

Signed-off-by: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:22 -07:00
Iulia Manda 2813893f8b kernel: conditionally support non-root users, groups and capabilities
There are a lot of embedded systems that run most or all of their
functionality in init, running as root:root.  For these systems,
supporting multiple users is not necessary.

This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for
non-root users, non-root groups, and capabilities optional.  It is enabled
under CONFIG_EXPERT menu.

When this symbol is not defined, UID and GID are zero in any possible case
and processes always have all capabilities.

The following syscalls are compiled out: setuid, setregid, setgid,
setreuid, setresuid, getresuid, setresgid, getresgid, setgroups,
getgroups, setfsuid, setfsgid, capget, capset.

Also, groups.c is compiled out completely.

In kernel/capability.c, capable function was moved in order to avoid
adding two ifdef blocks.

This change saves about 25 KB on a defconfig build.  The most minimal
kernels have total text sizes in the high hundreds of kB rather than
low MB.  (The 25k goes down a bit with allnoconfig, but not that much.

The kernel was booted in Qemu.  All the common functionalities work.
Adding users/groups is not possible, failing with -ENOSYS.

Bloat-o-meter output:
add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650)

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Iulia Manda <iulia.manda21@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:22 -07:00
Eric B Munson 5bbe3547aa mm: allow compaction of unevictable pages
Currently, pages which are marked as unevictable are protected from
compaction, but not from other types of migration.  The POSIX real time
extension explicitly states that mlock() will prevent a major page
fault, but the spirit of this is that mlock() should give a process the
ability to control sources of latency, including minor page faults.
However, the mlock manpage only explicitly says that a locked page will
not be written to swap and this can cause some confusion.  The
compaction code today does not give a developer who wants to avoid swap
but wants to have large contiguous areas available any method to achieve
this state.  This patch introduces a sysctl for controlling compaction
behavior with respect to the unevictable lru.  Users who demand no page
faults after a page is present can set compact_unevictable_allowed to 0
and users who need the large contiguous areas can enable compaction on
locked memory by leaving the default value of 1.

To illustrate this problem I wrote a quick test program that mmaps a
large number of 1MB files filled with random data.  These maps are
created locked and read only.  Then every other mmap is unmapped and I
attempt to allocate huge pages to the static huge page pool.  When the
compact_unevictable_allowed sysctl is 0, I cannot allocate hugepages
after fragmenting memory.  When the value is set to 1, allocations
succeed.

Signed-off-by: Eric B Munson <emunson@akamai.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:17 -07:00
Vladimir Davydov adbe427b92 memcg: zap mem_cgroup_lookup()
mem_cgroup_lookup() is a wrapper around mem_cgroup_from_id(), which
checks that id != 0 before issuing the function call.  Today, there is
no point in this additional check apart from optimization, because there
is no css with id <= 0, so that css_from_id, called by
mem_cgroup_from_id, will return NULL for any id <= 0.

Since mem_cgroup_from_id is only called from mem_cgroup_lookup, let us
zap mem_cgroup_lookup, substituting calls to it with mem_cgroup_from_id
and moving the check if id > 0 to css_from_id.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:16 -07:00
Linus Torvalds fa2e5c073a Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc
Pull exec domain removal from Richard Weinberger:
 "This series removes execution domain support from Linux.

  The idea behind exec domains was to support different ABIs.  The
  feature was never complete nor stable.  Let's rip it out and make the
  kernel signal handling code less complicated"

* 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits)
  arm64: Removed unused variable
  sparc: Fix execution domain removal
  Remove rest of exec domains.
  arch: Remove exec_domain from remaining archs
  arc: Remove signal translation and exec_domain
  xtensa: Remove signal translation and exec_domain
  xtensa: Autogenerate offsets in struct thread_info
  x86: Remove signal translation and exec_domain
  unicore32: Remove signal translation and exec_domain
  um: Remove signal translation and exec_domain
  tile: Remove signal translation and exec_domain
  sparc: Remove signal translation and exec_domain
  sh: Remove signal translation and exec_domain
  s390: Remove signal translation and exec_domain
  mn10300: Remove signal translation and exec_domain
  microblaze: Remove signal translation and exec_domain
  m68k: Remove signal translation and exec_domain
  m32r: Remove signal translation and exec_domain
  m32r: Autogenerate offsets in struct thread_info
  frv: Remove signal translation and exec_domain
  ...
2015-04-15 13:53:55 -07:00
Linus Torvalds fa927894bb Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs update from Al Viro:
 "Now that net-next went in...  Here's the next big chunk - killing
  ->aio_read() and ->aio_write().

  There'll be one more pile today (direct_IO changes and
  generic_write_checks() cleanups/fixes), but I'd prefer to keep that
  one separate"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  ->aio_read and ->aio_write removed
  pcm: another weird API abuse
  infinibad: weird APIs switched to ->write_iter()
  kill do_sync_read/do_sync_write
  fuse: use iov_iter_get_pages() for non-splice path
  fuse: switch to ->read_iter/->write_iter
  switch drivers/char/mem.c to ->read_iter/->write_iter
  make new_sync_{read,write}() static
  coredump: accept any write method
  switch /dev/loop to vfs_iter_write()
  serial2002: switch to __vfs_read/__vfs_write
  ashmem: use __vfs_read()
  export __vfs_read()
  autofs: switch to __vfs_write()
  new helper: __vfs_write()
  switch hugetlbfs to ->read_iter()
  coda: switch to ->read_iter/->write_iter
  ncpfs: switch to ->read_iter/->write_iter
  net/9p: remove (now-)unused helpers
  p9_client_attach(): set fid->uid correctly
  ...
2015-04-15 13:22:56 -07:00
David Howells 7682c91843 VFS: kernel/: d_inode() annotations
relayfs and tracefs are dealing with inodes of their own;
those two act as filesystem drivers

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:55 -04:00
David Howells 3b362157b2 VFS: audit: d_backing_inode() annotations
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:55 -04:00
Linus Torvalds 6c373ca893 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Add BQL support to via-rhine, from Tino Reichardt.

 2) Integrate SWITCHDEV layer support into the DSA layer, so DSA drivers
    can support hw switch offloading.  From Floria Fainelli.

 3) Allow 'ip address' commands to initiate multicast group join/leave,
    from Madhu Challa.

 4) Many ipv4 FIB lookup optimizations from Alexander Duyck.

 5) Support EBPF in cls_bpf classifier and act_bpf action, from Daniel
    Borkmann.

 6) Remove the ugly compat support in ARP for ugly layers like ax25,
    rose, etc.  And use this to clean up the neigh layer, then use it to
    implement MPLS support.  All from Eric Biederman.

 7) Support L3 forwarding offloading in switches, from Scott Feldman.

 8) Collapse the LOCAL and MAIN ipv4 FIB tables when possible, to speed
    up route lookups even further.  From Alexander Duyck.

 9) Many improvements and bug fixes to the rhashtable implementation,
    from Herbert Xu and Thomas Graf.  In particular, in the case where
    an rhashtable user bulk adds a large number of items into an empty
    table, we expand the table much more sanely.

10) Don't make the tcp_metrics hash table per-namespace, from Eric
    Biederman.

11) Extend EBPF to access SKB fields, from Alexei Starovoitov.

12) Split out new connection request sockets so that they can be
    established in the main hash table.  Much less false sharing since
    hash lookups go direct to the request sockets instead of having to
    go first to the listener then to the request socks hashed
    underneath.  From Eric Dumazet.

13) Add async I/O support for crytpo AF_ALG sockets, from Tadeusz Struk.

14) Support stable privacy address generation for RFC7217 in IPV6.  From
    Hannes Frederic Sowa.

15) Hash network namespace into IP frag IDs, also from Hannes Frederic
    Sowa.

16) Convert PTP get/set methods to use 64-bit time, from Richard
    Cochran.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1816 commits)
  fm10k: Bump driver version to 0.15.2
  fm10k: corrected VF multicast update
  fm10k: mbx_update_max_size does not drop all oversized messages
  fm10k: reset head instead of calling update_max_size
  fm10k: renamed mbx_tx_dropped to mbx_tx_oversized
  fm10k: update xcast mode before synchronizing multicast addresses
  fm10k: start service timer on probe
  fm10k: fix function header comment
  fm10k: comment next_vf_mbx flow
  fm10k: don't handle mailbox events in iov_event path and always process mailbox
  fm10k: use separate workqueue for fm10k driver
  fm10k: Set PF queues to unlimited bandwidth during virtualization
  fm10k: expose tx_timeout_count as an ethtool stat
  fm10k: only increment tx_timeout_count in Tx hang path
  fm10k: remove extraneous "Reset interface" message
  fm10k: separate PF only stats so that VF does not display them
  fm10k: use hw->mac.max_queues for stats
  fm10k: only show actual queues, not the maximum in hardware
  fm10k: allow creation of VLAN on default vid
  fm10k: fix unused warnings
  ...
2015-04-15 09:00:47 -07:00
Rusty Russell b9cc4489c6 params: handle quotes properly for values not of form foo="bar".
When starting kernel with arguments like:
  init=/bin/sh -c "echo arguments"
the trailing double quote is not removed which results in following command
being executed:
  /bin/sh -c 'echo arguments"'

Reported-by: Arthur Gautier <baloo@gandi.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15 13:31:23 +09:30
Linus Torvalds 2481bc7528 Power management and ACPI updates for v4.1-rc1
- Generic PM domains support update including new PM domain
    callbacks to handle device initialization better (Russell King,
    Rafael J Wysocki, Kevin Hilman).
 
  - Unified device properties API update including a new mechanism
    for accessing data provided by platform initialization code
    (Rafael J Wysocki, Adrian Hunter).
 
  - ARM cpuidle update including ARM32/ARM64 handling consolidation
    (Daniel Lezcano).
 
  - intel_idle update including support for the Silvermont Core in
    the Baytrail SOC and for the Airmont Core in the Cherrytrail and
    Braswell SOCs (Len Brown, Mathias Krause).
 
  - New cpufreq driver for Hisilicon ACPU (Leo Yan).
 
  - intel_pstate update including support for the Knights Landing
    chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi).
 
  - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann).
 
  - powernv cpufreq driver update (Shilpasri G Bhat).
 
  - devfreq update including Tegra support changes (Tomeu Vizoso,
    MyungJoo Ham, Chanwoo Choi).
 
  - powercap RAPL (Running-Average Power Limit) driver update
    including support for Intel Broadwell server chips (Jacob Pan,
    Mathias Krause).
 
  - ACPI device enumeration update related to the handling of the
    special PRP0001 device ID allowing DT-style 'compatible' property
    to be used for ACPI device identification (Rafael J Wysocki).
 
  - ACPI EC driver update including limited _DEP support (Lan Tianyu,
    Lv Zheng).
 
  - ACPI backlight driver update including a new mechanism to allow
    native backlight handling to be forced on non-Windows 8 systems
    and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede).
 
  - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu).
 
  - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
    Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki).
 
  - Fixes related to suspend-to-idle for the iTCO watchdog driver and
    the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu).
 
  - PM tracing support for the suspend phase of system suspend/resume
    transitions (Zhonghui Fu).
 
  - Configurable delay for the system suspend/resume testing facility
    (Brian Norris).
 
  - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki).
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJVLbO+AAoJEILEb/54YlRx5N4QAJXsmEW1FL2l6mMAyTQkEsVj
 nbqjF9I6aJgYM9+i8GKaZJxpN17SAZ7Ii7aCAXjPwX8AvjT70+gcZr+KDWtPir61
 B75VNVEcUYOR4vOF5Z6rQcQMlhGPkfMOJYXFMahpOG6DdPbVh1x2/tuawfc6IC0V
 a6S/fln6WqHrXQ+8swDSv1KuZsav6+8AQaTlNUQkkuXdY9b3k/3xiy5C2K26APP8
 x1B39iAF810qX6ipnK0gEOC3Vs29dl7hvNmgOVmmkBGVS7+pqTuy5n1/9M12cDRz
 78IQ7DXB0NcSwr5tdrmGVUyH0Q6H9lnD3vO7MJkYwKDh5a/2MiBr2GZc4KHDKDWn
 E1sS27f1Pdn9qnpWLzTcY+yYNV3EEyre56L2fc+sh+Xq9sNOjUah+Y/eAej/IxYD
 XYRf+GAj768yCJgNP+Y3PJES/PRh+0IZ/dn5k0Qq2iYvc8mcObyG6zdQIvCucv/i
 70uV1Z2GWEb31cI9TUV8o5GrMW3D0KI9EsCEEpiFFUnhjNog3AWcerGgFQMHxu7X
 ZnNSzudvek+XJ3NtpbPgTiJAmnMz8bDvBQm3G1LUO2TQdjYTU6YMUHsfzXs8DL6c
 aIMWO4stkVuDtWrlT/hfzIXepliccyXmSP6sbH+zNNCepulXe5C4M2SftaDi4l/B
 uIctXWznvHoGys+EFL+v
 =erd3
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...
2015-04-14 20:21:54 -07:00
Paul E. McKenney 8d7dc9283f rcu: Control grace-period delays directly from value
In a misguided attempt to avoid an #ifdef, the use of the
gp_init_delay module parameter was conditioned on the corresponding
RCU_TORTURE_TEST_SLOW_INIT Kconfig variable, using IS_ENABLED() at
the point of use in the code.  This meant that the compiler always saw
the delay, which meant that RCU_TORTURE_TEST_SLOW_INIT_DELAY had to be
unconditionally defined.  This in turn caused "make oldconfig" to ask
pointless questions about the value of RCU_TORTURE_TEST_SLOW_INIT_DELAY
in cases where it was not even used.

This commit avoids these pointless questions by defining gp_init_delay
under #ifdef.  In one branch, gp_init_delay is initialized to
RCU_TORTURE_TEST_SLOW_INIT_DELAY and is also a module parameter (thus
allowing boot-time modification), and in the other branch gp_init_delay
is a const variable initialized by default to zero.

This approach also simplifies the code at the delay point by eliminating
the IS_DEFINED().  Because gp_init_delay is constant zero in the no-delay
case intended for production use, the "gp_init_delay > 0" check causes
the delay to become dead code, as desired in this case.  In addition,
this commit replaces magic constant "10" with the preprocessor variable
PER_RCU_NODE_PERIOD, which controls the number of grace periods that
are allowed to elapse at full speed before a delay is inserted.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-04-14 19:33:59 -07:00
Linus Torvalds 1dcf58d6e6 Merge branch 'akpm' (patches from Andrew)
Merge first patchbomb from Andrew Morton:

 - arch/sh updates

 - ocfs2 updates

 - kernel/watchdog feature

 - about half of mm/

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (122 commits)
  Documentation: update arch list in the 'memtest' entry
  Kconfig: memtest: update number of test patterns up to 17
  arm: add support for memtest
  arm64: add support for memtest
  memtest: use phys_addr_t for physical addresses
  mm: move memtest under mm
  mm, hugetlb: abort __get_user_pages if current has been oom killed
  mm, mempool: do not allow atomic resizing
  memcg: print cgroup information when system panics due to panic_on_oom
  mm: numa: remove migrate_ratelimited
  mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
  mm: split ET_DYN ASLR from mmap ASLR
  s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
  mm: expose arch_mmap_rnd when available
  s390: standardize mmap_rnd() usage
  powerpc: standardize mmap_rnd() usage
  mips: extract logic for mmap_rnd()
  arm64: standardize mmap_rnd() usage
  x86: standardize mmap_rnd() usage
  arm: factor out mmap ASLR into mmap_rnd
  ...
2015-04-14 16:49:17 -07:00
David Rientjes 6e276d2a51 kernel, cpuset: remove exception for __GFP_THISNODE
Nothing calls __cpuset_node_allowed() with __GFP_THISNODE set anymore, so
remove the obscure comment about it and its special-case exception.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pravin Shelar <pshelar@nicira.com>
Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:03 -07:00
Ulrich Obergfell 692297d8f9 watchdog: introduce the hardlockup_detector_disable() function
Have kvm_guest_init() use hardlockup_detector_disable() instead of
watchdog_enable_hardlockup_detector(false).

Remove the watchdog_hardlockup_detector_is_enabled() and the
watchdog_enable_hardlockup_detector() function which are no longer needed.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:59 -07:00
Ulrich Obergfell b2f57c3a0d watchdog: clean up some function names and arguments
Rename the update_timers*() functions to update_watchdog*().

Remove the boolean argument from watchdog_enable_all_cpus() because
update_watchdog_all_cpus() is now a generic function to change the run
state of the lockup detectors and to have the lockup detectors use a new
sample period.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:59 -07:00
Ulrich Obergfell 195daf665a watchdog: enable the new user interface of the watchdog mechanism
With the current user interface of the watchdog mechanism it is only
possible to disable or enable both lockup detectors at the same time.
This series introduces new kernel parameters and changes the semantics of
some existing kernel parameters, so that the hard lockup detector and the
soft lockup detector can be disabled or enabled individually.  With this
series applied, the user interface is as follows.

- parameters in /proc/sys/kernel

  . soft_watchdog
    This is a new parameter to control and examine the run state of
    the soft lockup detector.

  . nmi_watchdog
    The semantics of this parameter have changed. It can now be used
    to control and examine the run state of the hard lockup detector.

  . watchdog
    This parameter is still available to control the run state of both
    lockup detectors at the same time. If this parameter is examined,
    it shows the logical OR of soft_watchdog and nmi_watchdog.

  . watchdog_thresh
    The semantics of this parameter are not affected by the patch.

- kernel command line parameters

  . nosoftlockup
    The semantics of this parameter have changed. It can now be used
    to disable the soft lockup detector at boot time.

  . nmi_watchdog=0 or nmi_watchdog=1
    Disable or enable the hard lockup detector at boot time. The patch
    introduces '=1' as a new option.

  . nowatchdog
    The semantics of this parameter are not affected by the patch. It
    is still available to disable both lockup detectors at boot time.

Also, remove the proc_dowatchdog() function which is no longer needed.

[dzickus@redhat.com: wrote changelog]
[dzickus@redhat.com: update documentation for kernel params and sysctl]
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:59 -07:00
Ulrich Obergfell bcfba4f4bf watchdog: implement error handling for failure to set up hardware perf events
If watchdog_nmi_enable() fails to set up the hardware perf event of one
CPU, the entire hard lockup detector is deemed unreliable.  Hence, disable
the hard lockup detector and shut down the hardware perf events on all
CPUs.

[dzickus@redhat.com: update comments to explain some code]
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:59 -07:00
Ulrich Obergfell 83a80a3907 watchdog: introduce separate handlers for parameters in /proc/sys/kernel
Separate handlers for each watchdog parameter in /proc/sys/kernel replace
the proc_dowatchdog() function.  Three of those handlers merely call
proc_watchdog_common() with one different argument.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:59 -07:00
Ulrich Obergfell ef246a216b watchdog: introduce proc_watchdog_common()
Three of four handlers for the watchdog parameters in /proc/sys/kernel
essentially have to do the same thing.

  if the parameter is being read {
    return the state of the corresponding bit(s) in 'watchdog_enabled'
  } else {
    set/clear the state of the corresponding bit(s) in 'watchdog_enabled'
    update the run state of the lockup detector(s)
  }

Hence, introduce a common function that can be called by those handlers.
The callers pass a 'bit mask' to this function to indicate which bit(s)
should be set/cleared in 'watchdog_enabled'.

This function handles an uncommon race with watchdog_nmi_enable() where a
concurrent update of 'watchdog_enabled' is possible.  We use 'cmpxchg' to
detect the concurrency.  [This avoids introducing a new spinlock or a
mutex to synchronize updates of 'watchdog_enabled'.  Using the same lock
or mutex in watchdog thread context and in system call context needs to be
considered carefully because it can make the code prone to deadlock
situations in connection with parking/unparking the watchdog threads.]

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:59 -07:00
Ulrich Obergfell f54c2274f5 watchdog: move definition of 'watchdog_proc_mutex' outside of proc_dowatchdog()
This series removes proc_dowatchdog().  Since multiple new functions need
the 'watchdog_proc_mutex' to serialize access to the watchdog parameters
in /proc/sys/kernel, move the mutex outside of any function.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:58 -07:00
Ulrich Obergfell a0c9cbb93d watchdog: introduce the proc_watchdog_update() function
This series introduces a separate handler for each watchdog parameter in
/proc/sys/kernel.  The separate handlers need a common function that they
can call to update the run state of the lockup detectors, or to have the
lockup detectors use a new sample period.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:58 -07:00
Ulrich Obergfell 84d56e66b9 watchdog: new definitions and variables, initialization
The hardlockup and softockup had always been tied together.  Due to the
request of KVM folks, they had a need to have one enabled but not the
other.  Internally rework the code to split things apart more cleanly.

There is a bunch of churn here, but the end result should be code that
should be easier to maintain and fix without knowing the internals of what
is going on.

This patch (of 9):

Introduce new definitions and variables to separate the user interface in
/proc/sys/kernel from the internal run state of the lockup detectors.  The
internal run state is represented by two bits in a new variable that is
named 'watchdog_enabled'.  This helps simplify the code, for example:

- In order to check if any of the two lockup detectors is enabled,
  it is sufficient to check if 'watchdog_enabled' is not zero.

- In order to enable/disable one or both lockup detectors,
  it is sufficient to set/clear one or both bits in 'watchdog_enabled'.

- Concurrent updates of 'watchdog_enabled' need not be synchronized via
  a spinlock or a mutex. Updates can either be atomic or concurrency can
  be detected by using 'cmpxchg'.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:58 -07:00
Linus Torvalds ca2ec32658 Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:
 "Part one:

   - struct filename-related cleanups

   - saner iov_iter_init() replacements (and switching the syscalls to
     use of those)

   - ntfs switch to ->write_iter() (Anton)

   - aio cleanups and splitting iocb into common and async parts
     (Christoph)

   - assorted fixes (me, bfields, Andrew Elble)

  There's a lot more, including the completion of switchover to
  ->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags
  race fixes, etc, but that goes after #for-davem merge.  David has
  pulled it, and once it's in I'll send the next vfs pull request"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits)
  sg_start_req(): use import_iovec()
  sg_start_req(): make sure that there's not too many elements in iovec
  blk_rq_map_user(): use import_single_range()
  sg_io(): use import_iovec()
  process_vm_access: switch to {compat_,}import_iovec()
  switch keyctl_instantiate_key_common() to iov_iter
  switch {compat_,}do_readv_writev() to {compat_,}import_iovec()
  aio_setup_vectored_rw(): switch to {compat_,}import_iovec()
  vmsplice_to_user(): switch to import_iovec()
  kill aio_setup_single_vector()
  aio: simplify arguments of aio_setup_..._rw()
  aio: lift iov_iter_init() into aio_setup_..._rw()
  lift iov_iter into {compat_,}do_readv_writev()
  NFS: fix BUG() crash in notify_change() with patch to chown_common()
  dcache: return -ESTALE not -EBUSY on distributed fs race
  NTFS: Version 2.1.32 - Update file write from aio_write to write_iter.
  VFS: Add iov_iter_fault_in_multipages_readable()
  drop bogus check in file_open_root()
  switch security_inode_getattr() to struct path *
  constify tomoyo_realpath_from_path()
  ...
2015-04-14 15:31:03 -07:00
Linus Torvalds 6c8a53c9e6 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf changes from Ingo Molnar:
 "Core kernel changes:

   - One of the more interesting features in this cycle is the ability
     to attach eBPF programs (user-defined, sandboxed bytecode executed
     by the kernel) to kprobes.

     This allows user-defined instrumentation on a live kernel image
     that can never crash, hang or interfere with the kernel negatively.
     (Right now it's limited to root-only, but in the future we might
     allow unprivileged use as well.)

     (Alexei Starovoitov)

   - Another non-trivial feature is per event clockid support: this
     allows, amongst other things, the selection of different clock
     sources for event timestamps traced via perf.

     This feature is sought by people who'd like to merge perf generated
     events with external events that were measured with different
     clocks:

       - cluster wide profiling

       - for system wide tracing with user-space events,

       - JIT profiling events

     etc.  Matching perf tooling support is added as well, available via
     the -k, --clockid <clockid> parameter to perf record et al.

     (Peter Zijlstra)

  Hardware enablement kernel changes:

   - x86 Intel Processor Trace (PT) support: which is a hardware tracer
     on steroids, available on Broadwell CPUs.

     The hardware trace stream is directly output into the user-space
     ring-buffer, using the 'AUX' data format extension that was added
     to the perf core to support hardware constraints such as the
     necessity to have the tracing buffer physically contiguous.

     This patch-set was developed for two years and this is the result.
     A simple way to make use of this is to use BTS tracing, the PT
     driver emulates BTS output - available via the 'intel_bts' PMU.
     More explicit PT specific tooling support is in the works as well -
     will probably be ready by 4.2.

     (Alexander Shishkin, Peter Zijlstra)

   - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
     feature of Intel Xeon CPUs that allows the measurement and
     allocation/partitioning of caches to individual workloads.

     These kernel changes expose the measurement side as a new PMU
     driver, which exposes various QoS related PMU events.  (The
     partitioning change is work in progress and is planned to be merged
     as a cgroup extension.)

     (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
     Waskiewicz Jr)

   - x86 Intel Haswell LBR call stack support: this is a new Haswell
     feature that allows the hardware recording of call chains, plus
     tooling support.  To activate this feature you have to enable it
     via the new 'lbr' call-graph recording option:

        perf record --call-graph lbr
        perf report

     or:

        perf top --call-graph lbr

     This hardware feature is a lot faster than stack walk or dwarf
     based unwinding, but has some limitations:

       - It reuses the current LBR facility, so LBR call stack and
         branch record can not be enabled at the same time.

       - It is only available for user-space callchains.

     (Yan, Zheng)

   - x86 Intel Broadwell CPU support and various event constraints and
     event table fixes for earlier models.

     (Andi Kleen)

   - x86 Intel HT CPUs event scheduling workarounds.  This is a complex
     CPU bug affecting the SNB,IVB,HSW families that results in counter
     value corruption.  The mitigation code is automatically enabled and
     is transparent.

     (Maria Dimakopoulou, Stephane Eranian)

  The perf tooling side had a ton of changes in this cycle as well, so
  I'm only able to list the user visible changes here, in addition to
  the tooling changes outlined above:

  User visible changes affecting all tools:

      - Improve support of compressed kernel modules (Jiri Olsa)
      - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
      - Bash completion for subcommands (Yunlong Song)
      - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
      - Support missing -f to override perf.data file ownership. (Yunlong Song)
      - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)

  User visible changes in individual tools:

    'perf data':

        New tool for converting perf.data to other formats, initially
        for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
        Sebastian Siewior)

    'perf diff':

        Add --kallsyms option (David Ahern)

    'perf list':

        Allow listing events with 'tracepoint' prefix (Yunlong Song)

        Sort the output of the command (Yunlong Song)

    'perf kmem':

        Respect -i option (Jiri Olsa)

        Print big numbers using thousands' group (Namhyung Kim)

        Allow -v option (Namhyung Kim)

        Fix alignment of slab result table (Namhyung Kim)

    'perf probe':

        Support multiple probes on different binaries on the same command line (Masami Hiramatsu)

        Support unnamed union/structure members data collection. (Masami Hiramatsu)

        Check kprobes blacklist when adding new events. (Masami Hiramatsu)

    'perf record':

        Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)

        Support recording running/enabled time (Andi Kleen)

    'perf sched':

        Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)

    'perf report' and 'perf top':

        Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)

        Indicate which callchain entries are annotated in the
        TUI hists browser (Arnaldo Carvalho de Melo)

        Add pid/tid filtering to 'report' and 'script' commands (David Ahern)

        Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
        cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
        events (Arnaldo Carvalho de Melo)

    'perf stat':

        Report unsupported events properly (Suzuki K. Poulose)

        Output running time and run/enabled ratio in CSV mode (Andi Kleen)

    'perf trace':

        Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)

        Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)

        Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)

        Dump stack on segfaults (Arnaldo Carvalho de Melo)

        No need to explicitely enable evsels for workload started from perf, let it
        be enabled via perf_event_attr.enable_on_exec, removing some events that take
        place in the 'perf trace' before a workload is really started by it.
        (Arnaldo Carvalho de Melo)

        Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)

  There's also been a ton of infrastructure work done, such as the
  split-out of perf's build system into tools/build/ and other changes -
  see the shortlog and changelog for details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
  perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
  perf evlist: Fix type for references to data_head/tail
  perf probe: Check the orphaned -x option
  perf probe: Support multiple probes on different binaries
  perf buildid-list: Fix segfault when show DSOs with hits
  perf tools: Fix cross-endian analysis
  perf tools: Fix error path to do closedir() when synthesizing threads
  perf tools: Fix synthesizing fork_event.ppid for non-main thread
  perf tools: Add 'I' event modifier for exclude_idle bit
  perf report: Don't call map__kmap if map is NULL.
  perf tests: Fix attr tests
  perf probe: Fix ARM 32 building error
  perf tools: Merge all perf_event_attr print functions
  perf record: Add clockid parameter
  perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
  perf sched replay: Support using -f to override perf.data file ownership
  perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
  perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
  perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
  perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
  ...
2015-04-14 14:37:47 -07:00
Linus Torvalds e95e7f6270 Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NOHZ changes from Ingo Molnar:
 "This tree adds full dynticks support to KVM guests (support the
  disabling of the timer tick on the guest).  The main missing piece was
  the recognition of guest execution as RCU extended quiescent state and
  related changes"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kvm,rcu,nohz: use RCU extended quiescent state when running KVM guest
  context_tracking: Export context_tracking_user_enter/exit
  context_tracking: Run vtime_user_enter/exit only when state == CONTEXT_USER
  context_tracking: Add stub context_tracking_is_enabled
  context_tracking: Generalize context tracking APIs to support user and guest
  context_tracking: Rename context symbols to prepare for transition state
  ppc: Remove unused cpp symbols in kvm headers
2015-04-14 13:58:48 -07:00
Linus Torvalds 078838d565 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU changes from Ingo Molnar:
 "The main changes in this cycle were:

   - changes permitting use of call_rcu() and friends very early in
     boot, for example, before rcu_init() is invoked.

   - add in-kernel API to enable and disable expediting of normal RCU
     grace periods.

   - improve RCU's handling of (hotplug-) outgoing CPUs.

   - NO_HZ_FULL_SYSIDLE fixes.

   - tiny-RCU updates to make it more tiny.

   - documentation updates.

   - miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  cpu: Provide smpboot_thread_init() on !CONFIG_SMP kernels as well
  cpu: Defer smpboot kthread unparking until CPU known to scheduler
  rcu: Associate quiescent-state reports with grace period
  rcu: Yet another fix for preemption and CPU hotplug
  rcu: Add diagnostics to grace-period cleanup
  rcutorture: Default to grace-period-initialization delays
  rcu: Handle outgoing CPUs on exit from idle loop
  cpu: Make CPU-offline idle-loop transition point more precise
  rcu: Eliminate ->onoff_mutex from rcu_node structure
  rcu: Process offlining and onlining only at grace-period start
  rcu: Move rcu_report_unblock_qs_rnp() to common code
  rcu: Rework preemptible expedited bitmask handling
  rcu: Remove event tracing from rcu_cpu_notify(), used by offline CPUs
  rcutorture: Enable slow grace-period initializations
  rcu: Provide diagnostic option to slow down grace-period initialization
  rcu: Detect stalls caused by failure to propagate up rcu_node tree
  rcu: Eliminate empty HOTPLUG_CPU ifdef
  rcu: Simplify sync_rcu_preempt_exp_init()
  rcu: Put all orphan-callback-related code under same comment
  rcu: Consolidate offline-CPU callback initialization
  ...
2015-04-14 13:36:04 -07:00
Linus Torvalds eeee78cf77 Some clean ups and small fixes, but the biggest change is the addition
of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.
 
 Tracepoints have helper functions for the TP_printk() called
 __print_symbolic() and __print_flags() that lets a numeric number be
 displayed as a a human comprehensible text. What is placed in the
 TP_printk() is also shown in the tracepoint format file such that
 user space tools like perf and trace-cmd can parse the binary data
 and express the values too. Unfortunately, the way the TRACE_EVENT()
 macro works, anything placed in the TP_printk() will be shown pretty
 much exactly as is. The problem arises when enums are used. That's
 because unlike macros, enums will not be changed into their values
 by the C pre-processor. Thus, the enum string is exported to the
 format file, and this makes it useless for user space tools.
 
 The TRACE_DEFINE_ENUM() solves this by converting the enum strings
 in the TP_printk() format into their number, and that is what is
 shown to user space. For example, the tracepoint tlb_flush currently
 has this in its format file:
 
      __print_symbolic(REC->reason,
         { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
         { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
         { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
         { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })
 
 After adding:
 
      TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
      TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
      TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
      TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);
 
 Its format file will contain this:
 
      __print_symbolic(REC->reason,
         { 0, "flush on task switch" },
         { 1, "remote shootdown" },
         { 2, "local shootdown" },
         { 3, "local mm shootdown" })
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJVLBTuAAoJEEjnJuOKh9ldjHMIALdRS755TXCZGOf0r7O2akOR
 wMPeum7C+ae1mH+jCsJKUC0/jUfQKaMt/UxoHlipDgcGg8kD2jtGnGCw4Xlwvdsr
 y4rFmcTRSl1mo0zDSsg6ujoupHlVYN0+JPjrd7S3cv/llJoY49zcanNLF7S2XLeM
 dZCtWRLWYpBiWO68ai6AqJTnE/eGFIqBI048qb5Eg8dbK243SSeSIf9Ywhb+VsA+
 aq6F7cWI/H6j4tbeza8tAN19dcwenDro5EfCDY8ARQHJu1f6Y3+DLf2imjkd6Aiu
 JVAoGIjHIpI+djwCZC1u4gi4urjfOqYartrM3Q54tb3YWYqHeNqP2ASI2a4EpYk=
 =Ixwt
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Some clean ups and small fixes, but the biggest change is the addition
  of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.

  Tracepoints have helper functions for the TP_printk() called
  __print_symbolic() and __print_flags() that lets a numeric number be
  displayed as a a human comprehensible text.  What is placed in the
  TP_printk() is also shown in the tracepoint format file such that user
  space tools like perf and trace-cmd can parse the binary data and
  express the values too.  Unfortunately, the way the TRACE_EVENT()
  macro works, anything placed in the TP_printk() will be shown pretty
  much exactly as is.  The problem arises when enums are used.  That's
  because unlike macros, enums will not be changed into their values by
  the C pre-processor.  Thus, the enum string is exported to the format
  file, and this makes it useless for user space tools.

  The TRACE_DEFINE_ENUM() solves this by converting the enum strings in
  the TP_printk() format into their number, and that is what is shown to
  user space.  For example, the tracepoint tlb_flush currently has this
  in its format file:

     __print_symbolic(REC->reason,
        { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
        { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
        { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
        { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })

  After adding:

     TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
     TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);

  Its format file will contain this:

     __print_symbolic(REC->reason,
        { 0, "flush on task switch" },
        { 1, "remote shootdown" },
        { 2, "local shootdown" },
        { 3, "local mm shootdown" })"

* tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Add enum_map file to show enums that have been mapped
  writeback: Export enums used by tracepoint to user space
  v4l: Export enums used by tracepoints to user space
  SUNRPC: Export enums in tracepoints to user space
  mm: tracing: Export enums in tracepoints to user space
  irq/tracing: Export enums in tracepoints to user space
  f2fs: Export the enums in the tracepoints to userspace
  net/9p/tracing: Export enums in tracepoints to userspace
  x86/tlb/trace: Export enums in used by tlb_flush tracepoint
  tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
  tracing: Allow for modules to convert their enums to values
  tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values
  tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
  tracing: Give system name a pointer
  brcmsmac: Move each system tracepoints to their own header
  iwlwifi: Move each system tracepoints to their own header
  mac80211: Move message tracepoints to their own header
  tracing: Add TRACE_SYSTEM_VAR to xhci-hcd
  tracing: Add TRACE_SYSTEM_VAR to kvm-s390
  tracing: Add TRACE_SYSTEM_VAR to intel-sst
  ...
2015-04-14 10:49:03 -07:00
Linus Torvalds 3f3c73de77 This adds the new tracefs file system. This has been in linux-next for
more than one release, as I had it ready for the 4.0 merge window, but
 a last minute thing that needed to go into Linux first had to be done.
 That was that perf hard coded the file system number when reading
 /sys/kernel/debugfs/tracing directory making sure that the path had
 the debugfs mount # before it would parse the tracing file. This broke
 other use cases of perf, and the check is removed.
 
 Now when mounting /sys/kernel/debug, tracefs is automatically mounted
 in /sys/kernel/debug/tracing such that old tools will still see that
 path as expected. But now system admins can mount tracefs directly
 and not need to mount debugfs, which can expose security issues.
 A new directory is created when tracefs is configured such that
 system admins can now mount it separately (/sys/kernel/tracing).
 
 This branch is based off of Al Viro's vfs debugfs_automount branch
 at commit 163f9eb95a
 debugfs: Provide a file creation function that also takes an initial size
 to get the debugfs_create_automount() operation.
 I just noticed that Al rebased the pull to add his Signed-off-by to
 that commit, and the commit is now e59b4e9187.
 I did a git diff of those two and see they are the same. Only the
 latter has Al's SOB.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJVLA6YAAoJEEjnJuOKh9ldv6AH/1JUINDQwV+M0VTwzbLogloo
 Sco0byLhskmx5KLVD7Vs8BJAGrgHTdit32kzBGmLGJvVCKBa+c8lwmRw6rnXg3uX
 K4kGp7BIyn1/geXoGpCmDKaLGXhDcw49hRzejKDg/OqFtxKTsSeQtG8fo29ps9Do
 0VaF6UDp8gYplC2N2BfpB59LVndrITQ3mSsBBeFPvS7IxFJXAhDBOq2yi0aI6HyJ
 ICo2L/bA9HLxMuceWrXbsun+RP68+AQlnFfAtok7AcuBzUYPCKY0shT2VMOUtpTt
 1dGxMxq6q1ACfmY7gbp47WMX9aKjWcSEr0V+IYx/xex6Maf0Xsujsy99bKYUWvs=
 =OcgU
 -----END PGP SIGNATURE-----

Merge tag 'trace-4.1-tracefs' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracefs from Steven Rostedt:
 "This adds the new tracefs file system.

  This has been in linux-next for more than one release, as I had it
  ready for the 4.0 merge window, but a last minute thing that needed to
  go into Linux first had to be done.  That was that perf hard coded the
  file system number when reading /sys/kernel/debugfs/tracing directory
  making sure that the path had the debugfs mount # before it would
  parse the tracing file.  This broke other use cases of perf, and the
  check is removed.

  Now when mounting /sys/kernel/debug, tracefs is automatically mounted
  in /sys/kernel/debug/tracing such that old tools will still see that
  path as expected.  But now system admins can mount tracefs directly
  and not need to mount debugfs, which can expose security issues.  A
  new directory is created when tracefs is configured such that system
  admins can now mount it separately (/sys/kernel/tracing)"

* tag 'trace-4.1-tracefs' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have mkdir and rmdir be part of tracefs
  tracefs: Add directory /sys/kernel/tracing
  tracing: Automatically mount tracefs on debugfs/tracing
  tracing: Convert the tracing facility over to use tracefs
  tracefs: Add new tracefs file system
  tracing: Create cmdline tracer options on tracing fs init
  tracing: Only create tracer options files if directory exists
  debugfs: Provide a file creation function that also takes an initial size
2015-04-14 10:22:29 -07:00
Linus Torvalds 9497d7380b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching updates from Jiri Kosina:
 "These are mostly smaller things that got accumulated during the
  development cycle.  The unified solution is still being worked on and
  is not mature enough for 4.1 yet.

   - s390 livepatching support, from Jiri Slaby (has Ack from s390
     maintainers)

   - error handling simplification, from Josh Poimboeuf

   - two minor code cleanups from Josh Poimboeuf and Miroslav Benes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: add support on s390
  livepatch: remove unnecessary call to klp_find_object_module()
  livepatch: simplify disable error path
  livepatch: remove extern specifier from header files
2015-04-14 10:15:34 -07:00
Linus Torvalds 4fd48b45ff Merge branch 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Nothing too interesting.  Rik made cpuset cooperate better with
  isolcpus and there are several other cleanup patches"

* 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset, isolcpus: document relationship between cpusets & isolcpus
  cpusets, isolcpus: exclude isolcpus from load balancing in cpusets
  sched, isolcpu: make cpu_isolated_map visible outside scheduler
  cpuset: initialize cpuset a bit early
  cgroup: Use kvfree in pidlist_free()
  cgroup: call cgroup_subsys->bind on cgroup subsys initialization
2015-04-13 16:47:11 -07:00
Linus Torvalds 45141eeafe Merge branch 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "Workqueue now prints debug information at the end of sysrq-t which
  should be helpful when tracking down suspected workqueue stalls.  It
  only prints out the ones with something currently going on so it
  shouldn't add much output in most cases"

* 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Reorder sysfs code
  percpu: Fix trivial typos in comments
  workqueue: dump workqueues on sysrq-t
  workqueue: keep track of the flushing task and pool manager
  workqueue: make the workqueues list RCU walkable
2015-04-13 16:19:18 -07:00
Linus Torvalds 8954672d86 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq core updates from Thomas Gleixner:
 "Managerial summary:

  Core code:
   - final removal of IRQF_DISABLED
   - new state save/restore functions for virtualization support
   - wakeup support for stacked irqdomains
   - new function to solve the netpoll synchronization problem

 irqchips:
   - new driver for STi based devices
   - new driver for Vybrid MSCM
   - massive cleanup of the GIC driver by moving the GIC-addons to
     stacked irqdomains
   - the usual pile of fixes and updates to the various chip drivers"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  irqchip: GICv3: Add support for irq_[get, set]_irqchip_state()
  irqchip: GIC: Add support for irq_[get, set]_irqchip_state()
  genirq: Allow the irqchip state of an IRQ to be save/restored
  genirq: MSI: Fix freeing of unallocated MSI
  irqchip: renesas-irqc: Add wake-up support
  irqchip: armada-370-xp: Allow using wakeup source
  irqchip: mips-gic: Add new functions to start/stop the GIC counter
  irqchip: tegra: Add Tegra210 support
  irqchip: digicolor: Move digicolor_set_gc to init section
  irqchip: renesas-irqc: Add functional clock to bindings
  irqchip: renesas-irqc: Add minimal runtime PM support
  irqchip: renesas-irqc: Add more register documentation
  DT: exynos: update PMU binding
  ARM: exynos4/5: convert pmu wakeup to stacked domains
  irqchip: gic: Don't complain in gic_get_cpumask() if UP system
  ARM: zynq: switch from gic_arch_extn to gic_set_irqchip_flags
  ARM: ux500: switch from gic_arch_extn to gic_set_irqchip_flags
  ARM: shmobile: remove use of gic_arch_extn.irq_set_wake
  irqchip: gic: Add an entry point to set up irqchip flags
  ARM: omap: convert wakeupgen to stacked domains
  ...
2015-04-13 15:54:50 -07:00
Jiri Kosina bcf5d54589 Merge branch 'for-4.1/core-noarch' into for-linus 2015-04-13 23:57:20 +02:00
Linus Torvalds 7fd56474db Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Ingo Molnar:
 "The main changes in this cycle were:

   - clockevents state machine cleanups and enhancements (Viresh Kumar)

   - clockevents broadcast notifier horror to state machine conversion
     and related cleanups (Thomas Gleixner, Rafael J Wysocki)

   - clocksource and timekeeping core updates (John Stultz)

   - clocksource driver updates and fixes (Ben Dooks, Dmitry Osipenko,
     Hans de Goede, Laurent Pinchart, Maxime Ripard, Xunlei Pang)

   - y2038 fixes (Xunlei Pang, John Stultz)

   - NMI-safe ktime_get_raw_fast() and general refactoring of the clock
     code, in preparation to perf's per event clock ID support (Peter
     Zijlstra)

   - generic sched/clock fixes, optimizations and cleanups (Daniel
     Thompson)

   - clockevents cpu_down() race fix (Preeti U Murthy)"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (94 commits)
  timers/PM: Drop unnecessary braces from tick_freeze()
  timers/PM: Fix up tick_unfreeze()
  timekeeping: Get rid of stale comment
  clockevents: Cleanup dead cpu explicitely
  clockevents: Make tick handover explicit
  clockevents: Remove broadcast oneshot control leftovers
  sched/idle: Use explicit broadcast oneshot control function
  ARM: Tegra: Use explicit broadcast oneshot control function
  ARM: OMAP: Use explicit broadcast oneshot control function
  intel_idle: Use explicit broadcast oneshot control function
  ACPI/idle: Use explicit broadcast control function
  ACPI/PAD: Use explicit broadcast oneshot control function
  x86/amd/idle, clockevents: Use explicit broadcast oneshot control functions
  clockevents: Provide explicit broadcast oneshot control functions
  clockevents: Remove the broadcast control leftovers
  ARM: OMAP: Use explicit broadcast control function
  intel_idle: Use explicit broadcast control function
  cpuidle: Use explicit broadcast control function
  ACPI/processor: Use explicit broadcast control function
  ACPI/PAD: Use explicit broadcast control function
  ...
2015-04-13 11:08:28 -07:00
Linus Torvalds 49d2953c72 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "Major changes:

   - Reworked CPU capacity code, for better SMP load balancing on
     systems with assymetric CPUs. (Vincent Guittot, Morten Rasmussen)

   - Reworked RT task SMP balancing to be push based instead of pull
     based, to reduce latencies on large CPU count systems. (Steven
     Rostedt)

   - SCHED_DEADLINE support updates and fixes. (Juri Lelli)

   - SCHED_DEADLINE task migration support during CPU hotplug. (Wanpeng Li)

   - x86 mwait-idle optimizations and fixes. (Mike Galbraith, Len Brown)

   - sched/numa improvements. (Rik van Riel)

   - various cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
  sched/core: Drop debugging leftover trace_printk call
  sched/deadline: Support DL task migration during CPU hotplug
  sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()
  sched/deadline: Always enqueue on previous rq when dl_task_timer() fires
  sched/core: Remove unused argument from init_[rt|dl]_rq()
  sched/deadline: Fix rt runtime corruption when dl fails its global constraints
  sched/deadline: Avoid a superfluous check
  sched: Improve load balancing in the presence of idle CPUs
  sched: Optimize freq invariant accounting
  sched: Move CFS tasks to CPUs with higher capacity
  sched: Add SD_PREFER_SIBLING for SMT level
  sched: Remove unused struct sched_group_capacity::capacity_orig
  sched: Replace capacity_factor by usage
  sched: Calculate CPU's usage statistic and put it into struct sg_lb_stats::group_usage
  sched: Add struct rq::cpu_capacity_orig
  sched: Make scale_rt invariant with frequency
  sched: Make sched entity usage tracking scale-invariant
  sched: Remove frequency scaling from cpu_capacity
  sched: Track group sched_entity usage contributions
  sched: Add sched_avg::utilization_avg_contrib
  ...
2015-04-13 10:47:34 -07:00
Linus Torvalds cc76ee75a9 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking changes from Ingo Molnar:
 "Main changes:

   - jump label asm preparatory work for PowerPC (Anton Blanchard)

   - rwsem optimizations and cleanups (Davidlohr Bueso)

   - mutex optimizations and cleanups (Jason Low)

   - futex fix (Oleg Nesterov)

   - remove broken atomicity checks from {READ,WRITE}_ONCE() (Peter
     Zijlstra)"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  powerpc, jump_label: Include linux/jump_label.h to get HAVE_JUMP_LABEL define
  jump_label: Allow jump labels to be used in assembly
  jump_label: Allow asm/jump_label.h to be included in assembly
  locking/mutex: Further simplify mutex_spin_on_owner()
  locking: Remove atomicy checks from {READ,WRITE}_ONCE
  locking/rtmutex: Rename argument in the rt_mutex_adjust_prio_chain() documentation as well
  locking/rwsem: Fix lock optimistic spinning when owner is not running
  locking: Remove ACCESS_ONCE() usage
  locking/rwsem: Check for active lock before bailing on spinning
  locking/rwsem: Avoid deceiving lock spinners
  locking/rwsem: Set lock ownership ASAP
  locking/rwsem: Document barrier need when waking tasks
  locking/futex: Check PF_KTHREAD rather than !p->mm to filter out kthreads
  locking/mutex: Refactor mutex_spin_on_owner()
  locking/mutex: In mutex_spin_on_owner(), return true when owner changes
2015-04-13 10:27:28 -07:00
Linus Torvalds 9003601310 The most interesting bit here is irqfd/ioeventfd support for ARM and ARM64.
ARM/ARM64: fixes for live migration, irqfd and ioeventfd support (enabling
 vhost, too), page aging
 
 s390: interrupt handling rework, allowing to inject all local interrupts
 via new ioctl and to get/set the full local irq state for migration
 and introspection.  New ioctls to access memory by virtual address,
 and to get/set the guest storage keys.  SIMD support.
 
 MIPS: FPU and MIPS SIMD Architecture (MSA) support.  Includes some patches
 from Ralf Baechle's MIPS tree.
 
 x86: bugfixes (notably for pvclock, the others are small) and cleanups.
 Another small latency improvement for the TSC deadline timer.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJVJ9vmAAoJEL/70l94x66DoMEH/R3rh8IMf4jTiWRkcqohOMPX
 k1+NaSY/lCKayaSgggJ2hcQenMbQoXEOdslvaA/H0oC+VfJGK+lmU6E63eMyyhjQ
 Y+Px6L85NENIzDzaVu/TIWWuhil5PvIRr3VO8cvntExRoCjuekTUmNdOgCvN2ObW
 wswN2qRdPIeEj2kkulbnye+9IV4G0Ne9bvsmUdOdfSSdi6ZcV43JcvrpOZT++mKj
 RrKB+3gTMZYGJXMMLBwMkdl8mK1ozriD+q0mbomT04LUyGlPwYLl4pVRDBqyksD7
 KsSSybaK2E4i5R80WEljgDMkNqrCgNfg6VZe4n9Y+CfAAOToNnkMJaFEi+yuqbs=
 =yu2b
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "First batch of KVM changes for 4.1

  The most interesting bit here is irqfd/ioeventfd support for ARM and
  ARM64.

  Summary:

  ARM/ARM64:
     fixes for live migration, irqfd and ioeventfd support (enabling
     vhost, too), page aging

  s390:
     interrupt handling rework, allowing to inject all local interrupts
     via new ioctl and to get/set the full local irq state for migration
     and introspection.  New ioctls to access memory by virtual address,
     and to get/set the guest storage keys.  SIMD support.

  MIPS:
     FPU and MIPS SIMD Architecture (MSA) support.  Includes some
     patches from Ralf Baechle's MIPS tree.

  x86:
     bugfixes (notably for pvclock, the others are small) and cleanups.
     Another small latency improvement for the TSC deadline timer"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (146 commits)
  KVM: use slowpath for cross page cached accesses
  kvm: mmu: lazy collapse small sptes into large sptes
  KVM: x86: Clear CR2 on VCPU reset
  KVM: x86: DR0-DR3 are not clear on reset
  KVM: x86: BSP in MSR_IA32_APICBASE is writable
  KVM: x86: simplify kvm_apic_map
  KVM: x86: avoid logical_map when it is invalid
  KVM: x86: fix mixed APIC mode broadcast
  KVM: x86: use MDA for interrupt matching
  kvm/ppc/mpic: drop unused IRQ_testbit
  KVM: nVMX: remove unnecessary double caching of MAXPHYADDR
  KVM: nVMX: checks for address bits beyond MAXPHYADDR on VM-entry
  KVM: x86: cache maxphyaddr CPUID leaf in struct kvm_vcpu
  KVM: vmx: pass error code with internal error #2
  x86: vdso: fix pvclock races with task migration
  KVM: remove kvm_read_hva and kvm_read_hva_atomic
  KVM: x86: optimize delivery of TSC deadline timer interrupt
  KVM: x86: extract blocking logic from __vcpu_run
  kvm: x86: fix x86 eflags fixed bit
  KVM: s390: migrate vcpu interrupt state
  ...
2015-04-13 09:47:01 -07:00
Paul E. McKenney 00df35f991 cpu: Defer smpboot kthread unparking until CPU known to scheduler
Currently, smpboot_unpark_threads() is invoked before the incoming CPU
has been added to the scheduler's runqueue structures.  This might
potentially cause the unparked kthread to run on the wrong CPU, since the
correct CPU isn't fully set up yet.

That causes a sporadic, hard to debug boot crash triggering on some
systems, reported by Borislav Petkov, and bisected down to:

  2a442c9c64 ("x86: Use common outgoing-CPU-notification code")

This patch places smpboot_unpark_threads() in a CPU hotplug
notifier with priority set so that these kthreads are unparked just after
the CPU has been added to the runqueues.

Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-13 08:25:16 +02:00