* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Constify function scope static struct sched_param usage
sched: Fix strncmp operation
sched: Move sched_autogroup_exit() to free_signal_struct()
sched: Fix struct autogroup memory leak
sched: Mark autogroup_init() __init
sched: Consolidate the name of root_task_group and init_task_group
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
serial: apbuart: Fixup apbuart_console_init()
TTY: Add tty ioctl to figure device node of the system console.
tty: add 'active' sysfs attribute to tty0 and console device
drivers: serial: apbuart: Handle OF failures gracefully
Serial: Avoid unbalanced IRQ wake disable during resume
tty: fix typos/errors in tty_driver.h comments
pch_uart : fix warnings for 64bit compile
8250: fix uninitialized FIFOs
ip2: fix compiler warning on ip2main_pci_tbl
specialix: fix compiler warning on specialix_pci_tbl
rocket: fix compiler warning on rocket_pci_ids
8250: add a UPIO_DWAPB32 for 32 bit accesses
8250: use container_of() instead of casting
serial: omap-serial: Add support for kernel debugger
serial: fix pch_uart kconfig & build
drivers: char: hvc: add arm JTAG DCC console support
RS485 documentation: add 16C950 UART description
serial: ifx6x60: fix memory leak
serial: ifx6x60: free IRQ on error
Serial: EG20T: add PCH_UART driver
...
Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).
Function-scope statics are discouraged because they are
easily overlooked and can cause subtle bugs/races due to
their global (non-SMP safe) nature.
Linus noticed that we did this for sched_param - at minimum
make the const.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: Message-ID: <AANLkTinotRxScOHEb0HgFgSpGPkq_6jKTv5CfvnQM=ee@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
One of the operands, buf, is incorrect, since it is stripped and the
correct address for subsequent string comparing could change if
leading white spaces, if any, are removed from buf.
It is fixed by replacing buf with cmp.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <AANLkTinOPuYsVovrZpbuCCmG5deEyc8WgA_A1RJx_YK7@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Seems I lost a change somewhere, leaking memory.
sched: fix struct autogroup memory leak
Add missing change to actually use autogroup_free().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294222285.8369.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
autogroup_init() is only called at boot time.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294375425-31065-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
root_task_group is the leftover of USER_SCHED, now it's always
same to init_task_group.
But as Mike suggested, root_task_group is maybe the suitable name
to keep for a tree.
So in this patch:
init_task_group --> root_task_group
init_task_group_load --> root_task_group_load
INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD
Suggested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110107071736.GA32635@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Adds perf_event_time() to try and centralize access to event
timing and in particular ctx->time. Prepares for cgroup support.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d22059c.122ae30a.5e0e.ffff8b8b@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Replace all occurrences of:
event->cpu != -1 && event->cpu == smp_processor_id()
by a call to:
event_filter_match(event)
This makes the code more consistent and will make the cgroup
patch smaller.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d220593.2308e30a.48c5.ffff8ae9@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In particular this patch move perf_event_exit_task() before
cgroup_exit() to allow for cgroup support. The cgroup_exit()
function detaches the cgroups attached to a task.
Other movements include hoisting some definitions and inlines
at the top of perf_event.c
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4d22058b.cdace30a.4657.ffff95b1@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
blktrace.c block bio complete callback needs to gain a new argument to reflect
the newly added "error" tracepoint argument. This is needed to match the new
block_bio_complete TRACE_EVENT as of
commit de983a7bfcb7c020901ca6e2314cf55a4207ab5a.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Jeff Moyer <jmoyer@redhat.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).
Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.
This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix cgroupfs so as not to do this.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The saving of the ACPI NVS area during hibernation and suspend and
restoring it during the subsequent resume is entirely specific to
ACPI, so move it to drivers/acpi and drop the CONFIG_SUSPEND_NVS
configuration option which is redundant.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
When ioremap() fails (which might happen for some reason), we nicely
oops in suspend_nvs_save() due to NULL dereference by memcpy() in there.
Fail gracefully instead.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
* 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, suspend: Avoid unnecessary smp alternatives switch during suspend/resume
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64, asm: Use fxsaveq/fxrestorq in more places
* 'x86-hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hwmon: Add core threshold notification to therm_throt.c
* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, paravirt: Use native_halt on a halt, not native_safe_halt
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
locking, lockdep: Convert sprintf_symbol to %pS
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
irq: Better struct irqaction layout
* 'x86-security-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
module: Move RO/NX module protection to after ftrace module update
x86: Resume trampoline must be executable
x86: Add RO/NX protection for loadable kernel modules
x86: Add NX protection for kernel data
x86: Fix improper large page preservation
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
MAINTAINERS: Update timer related entries
timers: Use this_cpu_read
timerqueue: Make timerqueue_getnext() static inline
hrtimer: fix timerqueue conversion flub
hrtimers: Convert hrtimers to use timerlist infrastructure
timers: Fixup allmodconfig build issue
timers: Rename timerlist infrastructure to timerqueue
timers: Introduce timerlist infrastructure.
hrtimer: Remove stale comment on curr_timer
timer: Warn when del_timer_sync() is called in hardirq context
timer: Del_timer_sync() can be used in softirq context
timer: Make try_to_del_timer_sync() the same on SMP and UP
posix-timers: Annotate lock_timer()
timer: Permit statically-declared work with deferrable timers
time: Use ARRAY_SIZE macro in timecompare.c
timer: Initialize the field slack of timer_list
timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS
time: Compensate for rounding on odd-frequency clocksources
Fix up trivial conflict in MAINTAINERS
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
sched: Change wait_for_completion_*_timeout() to return a signed long
sched, autogroup: Fix reference leak
sched, autogroup: Fix potential access to freed memory
sched: Remove redundant CONFIG_CGROUP_SCHED ifdef
sched: Fix interactivity bug by charging unaccounted run-time on entity re-weight
sched: Move periodic share updates to entity_tick()
printk: Use this_cpu_{read|write} api on printk_pending
sched: Make pushable_tasks CONFIG_SMP dependant
sched: Add 'autogroup' scheduling feature: automated per session task groups
sched: Fix unregister_fair_sched_group()
sched: Remove unused argument dest_cpu to migrate_task()
mutexes, sched: Introduce arch_mutex_cpu_relax()
sched: Add some clock info to sched_debug
cpu: Remove incorrect BUG_ON
cpu: Remove unused variable
sched: Fix UP build breakage
sched: Make task dump print all 15 chars of proc comm
sched: Update tg->shares after cpu.shares write
sched: Allow update_cfs_load() to update global load
sched: Implement demand based update_cfs_load()
...
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (146 commits)
tools, perf: Documentation for the power events API
perf: Add calls to suspend trace point
perf script: Make some lists static
perf script: Use the default lost event handler
perf session: Warn about errors when processing pipe events too
perf tools: Fix perf_event.h header usage
perf test: Clarify some error reports in the open syscall test
x86, NMI: Add touch_nmi_watchdog to io_check_error delay
x86: Avoid calling arch_trigger_all_cpu_backtrace() at the same time
x86: Only call smp_processor_id in non-preempt cases
perf timechart: Adjust perf timechart to the new power events
perf: Clean up power events by introducing new, more generic ones
perf: Do not export power_frequency, but power_start event
perf test: Add test for counting open syscalls
perf evsel: Auto allocate resources needed for some methods
perf evsel: Use {cpu,thread}_map to shorten list of parameters
perf tools: Refactor all_tids to hold nr and the map
perf tools: Refactor cpumap to hold nr and the map
perf evsel: Introduce per cpu and per thread open helpers
perf evsel: Steal the counter reading routines from stat
...
* 'core-futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Add futex_q static initializer
futex: Replace fshared and clockrt with combined flags
futex: Cleanup stale fshared flag interfaces
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: remove unused __list_for_each_rcu() macro
rculist: fix borked __list_for_each_rcu() macro
rcu: reduce __call_rcu()-induced contention on rcu_node structures
rcu: limit rcu_node leaf-level fanout
rcu: fine-tune grace-period begin/end checks
rcu: Keep gpnum and completed fields synchronized
rcu: Stop chasing QS if another CPU did it for us
rcu: increase synchronize_sched_expedited() batching
rcu: Make synchronize_srcu_expedited() fast if running readers
rcu: fix race condition in synchronize_sched_expedited()
rcu: update documentation/comments for Lai's adoption patch
rcu,cleanup: simplify the code when cpu is dying
rcu,cleanup: move synchronize_sched_expedited() out of sched.c
rcu: get rid of obsolete "classic" names in TREE_RCU tracing
rcu: Distinguish between boosting and boosted
rcu: document TINY_RCU and TINY_PREEMPT_RCU tracing.
rcu: add tracing for TINY_RCU and TINY_PREEMPT_RCU
rcu: priority boosting for TINY_PREEMPT_RCU
rcu: move TINY_RCU from softirq to kthread
rcu: add priority-inversion testing to rcutorture
Uses the machine_suspend trace point, called from the
generic kernel suspend_devices_and_enter function.
Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
CC: Thomas Renninger <trenn@suse.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-pm@lists.linux-foundation.org
LKML-Reference: <1294253342-29056-2-git-send-email-j-pihet@ti.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
wait_for_completion_*_timeout() can return:
0: if the wait timed out
-ve: if the wait was interrupted
+ve: if the completion was completed.
As they currently return an 'unsigned long', the last two cases
are not easily distinguished which can easily result in buggy
code, as is the case for the recently added
wait_for_completion_interruptible_timeout() call in
net/sunrpc/cache.c
So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT
is LONG_MAX, a large +ve return value should never overflow.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110105125016.64ccab0e@notabene.brown>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The cgroup exit mess also uncovered a struct autogroup reference leak.
copy_process() was simply freeing vs putting the signal_struct,
stranding a reference.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
LKML-Reference: <1293784350.6839.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg pointed out that the /proc interface kref_get() useage may race with
the final put during autogroup_move_group(). A signal->autogroup assignment
may be in flight when the /proc interface dereference, leaving them taking
a reference to an already dead group.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292508592.5940.28.camel@maggy.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add these new power trace events:
power:cpu_idle
power:cpu_frequency
power:machine_suspend
The old C-state/idle accounting events:
power:power_start
power:power_end
Have now a replacement (but we are still keeping the old
tracepoints for compatibility):
power:cpu_idle
and
power:power_frequency
is replaced with:
power:cpu_frequency
power:machine_suspend is newly introduced.
Jean Pihet has a patch integrated into the generic layer
(kernel/power/suspend.c) which will make use of it.
the type= field got removed from both, it was never
used and the type is differed by the event type itself.
perf timechart userspace tool gets adjusted in a separate patch.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-3-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
power_frequency moved to drivers/cpufreq/cpufreq.c which has
to be compiled in, no need to export it.
intel_idle can a be module though...
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Jean Pihet <j-pihet@ti.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-2-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
The error message 'NMI watchdog failed to create perf event...'
does not make it clear that this is a fatal error for the
watchdog. It also currently prints the error value as a
pointer, rather than extracting the error code with PTR_ERR().
Fix that.
Add a note to the description of the 'nowatchdog' kernel
parameter to associate it with this message.
Reported-by: Cesare Leonardi <celeonar@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: 599368@bugs.debian.org
Cc: 608138@bugs.debian.org
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@kernel.org> # .37.x and later
LKML-Reference: <1294009362.3167.126.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When racing on adding into user cache, the new allocated from mm slab
is freed without putting user namespace.
Since the user namespace is already operated by getting, putting has
to be issued.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ring_buffer: Off-by-one and duplicate events in ring_buffer_read_page
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: print out alloc information with KERN_DEBUG instead of KERN_INFO
kthread_work: make lockdep happy
To avoid confusion with the meaning and return value of
pm_check_wakeup_events() replace it with pm_wakeup_pending() that
will work the other way around (ie. return true when system-wide
power transition should be aborted).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
When hibernation failed due to an error in swsusp_write() called by
hibernate(), it skips calling "power_down()" and returns. When
hibernate() is called again (probably after fixing up so that
swsusp_write() wouldn't fail again), before "in_suspend = 1" of
create_image is called, in_suspend should be 0. However, because
hibernate() did not reset "in_suspend" after a failure, it's already 1.
This patch fixes such inconsistency of "in_suspend" value.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Because hibernate calls hibernation_ops->leave() without checking
whether hibernation_ops->leave is NULL or not, hiberantion_set_ops
should WARN_ON if hibernation_ops->leave is NULL.
This patch added one more condition to check hibernation_ops->leave.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
After calling freeze_task(), try_to_freeze_tasks() see whether the
task is stopped or traced and if so, considers it to be frozen;
however, nothing guarantees that either the task being frozen sees
TIF_FREEZE or the freezer sees TASK_STOPPED -> TASK_RUNNING
transition. The task being frozen may wake up and not see TIF_FREEZE
while the freezer fails to notice the transition and believes the task
is still stopped.
This patch fixes the race by making freeze_task() always go through
fake_signal_wake_up() for applicable tasks. The function goes through
the target task's scheduler lock and thus guarantees that either the
target sees TIF_FREEZE or try_to_freeze_task() sees TASK_RUNNING.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Use the ccflags-$ flag instead of EXTRA_CFLAGS because EXTRA_CFLAGS is
deprecated and should now be switched. According to
(documentation/kbuild/makefiles.txt).
Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Fix two related problems in the event-copying loop of
ring_buffer_read_page.
The loop condition for copying events is off-by-one.
"len" is the remaining space in the caller-supplied page.
"size" is the size of the next event (or two events).
If len == size, then there is just enough space for the next event.
size was set to rb_event_ts_length, which may include the size of two
events if the first event is a time-extend, in order to assure time-
extends are kept together with the event after it. However,
rb_advance_reader always advances by one event. This would result in the
event after any time-extend being duplicated. Instead, get the size of
a single event for the memcpy, but use rb_event_ts_length for the loop
condition.
Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1293064704-8101-1-git-send-email-dhsharp@google.com>
LKML-Reference: <AANLkTin7nLrRPc9qGjdjHbeVDDWiJjAiYyb-L=gH85bx@mail.gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The commit:
84e1c6bb38
x86: Add RO/NX protection for loadable kernel modules
Broke the function tracer with this output:
------------[ cut here ]------------
WARNING: at kernel/trace/ftrace.c:1014 ftrace_bug+0x114/0x171()
Hardware name: Precision WorkStation 470
Modules linked in: i2c_core(+)
Pid: 86, comm: modprobe Not tainted 2.6.37-rc2+ #68
Call Trace:
[<ffffffff8104e957>] warn_slowpath_common+0x85/0x9d
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffff8104e989>] warn_slowpath_null+0x1a/0x1c
[<ffffffff810a9dfe>] ftrace_bug+0x114/0x171
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffff810aa0db>] ftrace_process_locs+0x1ae/0x274
[<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core]
[<ffffffff810aa29e>] ftrace_module_notify+0x39/0x44
[<ffffffff814405cf>] notifier_call_chain+0x37/0x63
[<ffffffff8106e054>] __blocking_notifier_call_chain+0x46/0x5b
[<ffffffff8106e07d>] blocking_notifier_call_chain+0x14/0x16
[<ffffffff8107ffde>] sys_init_module+0x73/0x1f3
[<ffffffff8100acf2>] system_call_fastpath+0x16/0x1b
---[ end trace 2aff4f4ca53ec746 ]---
ftrace faulted on writing [<ffffffffa00026db>]
__process_new_adapter+0x7/0x34 [i2c_core]
The cause was that the module text was set to read only before ftrace
could convert the calls to mcount to nops. Thus, the conversions failed
due to not being able to write to the text locations.
The simple fix is to move setting the module to read only after the
module notifiers are called (where ftrace sets the module mcounts to nops).
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The taskstats structure is internally aligned on 8 byte boundaries but the
layout of the aggregrate reply, with two NLA headers and the pid (each 4
bytes), actually force the entire structure to be unaligned. This causes
the kernel to issue unaligned access warnings on some architectures like
ia64. Unfortunately, some software out there doesn't properly unroll the
NLA packet and assumes that the start of the taskstats structure will
always be 20 bytes from the start of the netlink payload. Aligning the
start of the taskstats structure breaks this software, which we don't
want. So, for now the alignment only happens on architectures that
require it and those users will have to update to fixed versions of those
packages. Space is reserved in the packet only when needed. This ifdef
should be removed in several years e.g. 2012 once we can be confident
that fixed versions are installed on most systems. We add the padding
before the aggregate since the aggregate is already a defined type.
Commit 85893120 ("delayacct: align to 8 byte boundary on 64-bit systems")
previously addressed the alignment issues by padding out the pid field.
This was supposed to be a compatible change but the circumstances
described above mean that it wasn't. This patch backs out that change,
since it was a hack, and introduces a new NULL attribute type to provide
the padding. Padding the response with 4 bytes avoids allocating an
aligned taskstats structure and copying it back. Since the structure
weighs in at 328 bytes, it's too big to do it on the stack.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: Brian Rogers <brian@xyzw.org>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Guillaume Chazarain <guichaz@gmail.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Russell King reports:
| On the ARM dev boards, we have a 32-bit counter running at 24MHz. Calling
| clocks_calc_mult_shift(&mult, &shift, 24MHz, NSEC_PER_SEC, 60) gives
| us a multiplier of 2796202666 and a shift of 26.
|
| Over a large counter delta, this produces an error - lets take a count
| from 362976315 to 4280663372:
|
| (4280663372-362976315) * 2796202666 / 2^26 - (4280663372-362976315) * (1000/24)
| => -38.91872422891230269990
|
| Can we do better?
|
| (4280663372-362976315) * 2796202667 / 2^26 - (4280663372-362976315) * (1000/24)
| 19.45936211449532822051
|
| which is about twice as good as the 2796202666 multiplier.
|
| Looking at the equivalent divisions obtained, 2796202666 / 2^26 gives
| 41.66666665673255920410ns per tick, whereas 2796202667 / 2^26 gives
| 41.66666667163372039794ns. The actual value wanted is 1000/24 =
| 41.66666666666666666666ns.
Fix this by ensuring we round to nearest when calculating the
multiplier.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Olof Johansson <olof@lixom.net>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
spinlock in kthread_worker and wait_queue_head in kthread_work both
should be lockdep sensible, so change the interface to make it
suiltable for CONFIG_LOCKDEP.
tj: comment update
Reported-by: Nicolas <nicolas.mailhot@laposte.net>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Tested-by: Andy Walls <awalls@md.metrocast.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, destroy_workqueue() makes the workqueue deny all new
queueing by setting WQ_DYING and flushes the workqueue once before
proceeding with destruction; however, there are cases where work items
queue more related work items. Currently, such users need to
explicitly flush the workqueue multiple times depending on the
possible depth of such chained queueing.
This patch updates the queueing path such that a work item can queue
further work items on the same workqueue even when WQ_DYING is set.
The flush on destruction is automatically retried until the workqueue
is empty. This guarantees that the workqueue is empty on destruction
while allowing chained queueing.
The flush retry logic whines if it takes too many retries to drain the
workqueue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Linus reported that the new warning introduced by commit f26f9aff6a
"Sched: fix skip_clock_update optimization" triggers. The need_resched
flag can be set by other CPUs asynchronously so this debug check is
bogus - remove it.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <AANLkTinJ8hAG1TpyC+CSYPR47p48+1=E7fiC45hMXT_1@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-32: Make sure we can map all of lowmem if we need to
x86, vt-d: Handle previous faults after enabling fault handling
x86: Enable the intr-remap fault handling after local APIC setup
x86, vt-d: Fix the vt-d fault handling irq migration in the x2apic mode
x86, vt-d: Quirk for masking vtd spec errors to platform error handling logic
x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()
bootmem: Add alloc_bootmem_align()
x86, gcc-4.6: Use gcc -m options when building vdso
x86: HPET: Chose a paranoid safe value for the ETIME check
x86: io_apic: Avoid unused variable warning when CONFIG_GENERIC_PENDING_IRQ=n
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Fix off by one in perf_swevent_init()
perf: Fix duplicate events with multiple-pmu vs software events
ftrace: Have recordmcount honor endianness in fn_ELF_R_INFO
scripts/tags.sh: Add magic for trace-events
tracing: Fix panic when lseek() called on "trace" opened for writing
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix the irqtime code for 32bit
sched: Fix the irqtime code to deal with u64 wraps
nohz: Fix get_next_timer_interrupt() vs cpu hotplug
Sched: fix skip_clock_update optimization
sched: Cure more NO_HZ load average woes
Mike Galbraith reported poor interactivity[*] when the new shares distribution
code was combined with autogroups.
The root cause turns out to be a mis-ordering of accounting accrued execution
time and shares updates. Since update_curr() is issued hierarchically,
updating the parent entity weights to reflect child enqueue/dequeue results in
the parent's unaccounted execution time then being accrued (vs vruntime) at the
new weight as opposed to the weight present at accumulation.
While this doesn't have much effect on processes with timeslices that cross a
tick, it is particularly problematic for an interactive process (e.g. Xorg)
which incurs many (tiny) timeslices. In this scenario almost all updates are
at dequeue which can result in significant fairness perturbation (especially if
it is the only thread, resulting in potential {tg->shares, MIN_SHARES}
transitions).
Correct this by ensuring unaccounted time is accumulated prior to manipulating
an entity's weight.
[*] http://xkcd.com/619/ is perversely Nostradamian here.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20101216031038.159704378@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Long running entities that do not block (dequeue) require periodic updates to
maintain accurate share values. (Note: group entities with several threads are
quite likely to be non-blocking in many circumstances).
By virtue of being long-running however, we will see entity ticks (otherwise
the required update occurs in dequeue/put and we are done). Thus we can move
the detection (and associated work) for these updates into the periodic path.
This restores the 'atomicity' of update_curr() with respect to accounting.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101216031038.067028969@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
x86: avoid high BIOS area when allocating address space
x86: avoid E820 regions when allocating address space
x86: avoid low BIOS area when allocating address space
resources: add arch hook for preventing allocation in reserved areas
Revert "resources: support allocating space within a region from the top down"
Revert "PCI: allocate bus resources from the top down"
Revert "x86/PCI: allocate space from the end of a region, not the beginning"
Revert "x86: allocate space within a region top-down"
Revert "PCI: fix pci_bus_alloc_resource() hang, prefer positive decode"
PCI: Update MCP55 quirk to not affect non HyperTransport variants
The irq work queue is a per cpu object and it is sufficient for
synchronization if per cpu atomics are used. Doing so simplifies
the code and reduces the overhead of the code.
Before:
christoph@linux-2.6$ size kernel/irq_work.o
text data bss dec hex filename
451 8 1 460 1cc kernel/irq_work.o
After:
christoph@linux-2.6$ size kernel/irq_work.o
text data bss dec hex filename
438 8 1 447 1bf kernel/irq_work.o
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Christoph Lameter <cl@linux.com>
When the current __call_rcu() function was written, the expedited
APIs did not exist. The __call_rcu() implementation therefore went
to great lengths to detect the end of old grace periods and to start
new ones, all in the name of reducing grace-period latency. Now the
expedited APIs do exist, and the usage of __call_rcu() has increased
considerably. This commit therefore causes __call_rcu() to avoid
worrying about grace periods unless there are a large number of
RCU callbacks stacked up on the current CPU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Some recent benchmarks have indicated possible lock contention on the
leaf-level rcu_node locks. This commit therefore limits the number of
CPUs per leaf-level rcu_node structure to 16, in other words, there
can be at most 16 rcu_data structures fanning into a given rcu_node
structure. Prior to this, the limit was 32 on 32-bit systems and 64 on
64-bit systems.
Note that the fanout of non-leaf rcu_node structures is unchanged. The
organization of accesses to the rcu_node tree is such that references
to non-leaf rcu_node structures are much less frequent than to the
leaf structures.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Use the CPU's bit in rnp->qsmask to determine whether or not the CPU
should try to report a quiescent state. Handle overflow in the check
for rdp->gpnum having fallen behind.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When a CPU that was in an extended quiescent state wakes
up and catches up with grace periods that remote CPUs
completed on its behalf, we update the completed field
but not the gpnum that keeps a stale value of a backward
grace period ID.
Later, note_new_gpnum() will interpret the shift between
the local CPU and the node grace period ID as some new grace
period to handle and will then start to hunt quiescent state.
But if every grace periods have already been completed, this
interpretation becomes broken. And we'll be stuck in clusters
of spurious softirqs because rcu_report_qs_rdp() will make
this broken state run into infinite loop.
The solution, as suggested by Lai Jiangshan, is to ensure that
the gpnum and completed fields are well synchronized when we catch
up with completed grace periods on their behalf by other cpus.
This way we won't start noting spurious new grace periods.
Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
When a CPU is idle and others CPUs handled its extended
quiescent state to complete grace periods on its behalf,
it will catch up with completed grace periods numbers
when it wakes up.
But at this point there might be no more grace period to
complete, but still the woken CPU always keeps its stale
qs_pending value and will then continue to chase quiescent
states even if its not needed anymore.
This results in clusters of spurious softirqs until a new
real grace period is started. Because if we continue to
chase quiescent states but we have completed every grace
periods, rcu_report_qs_rdp() is puzzled and makes that
state run into infinite loops.
As suggested by Lai Jiangshan, just reset qs_pending if
someone completed every grace periods on our behalf.
Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The fix in commit #6a0cc49 requires more than three concurrent instances
of synchronize_sched_expedited() before batching is possible. This
patch uses a ticket-counter-like approach that is also not unrelated to
Lai Jiangshan's Ring RCU to allow sharing of expedited grace periods even
when there are only two concurrent instances of synchronize_sched_expedited().
This commit builds on Tejun's original posting, which may be found at
http://lkml.org/lkml/2010/11/9/204, adding memory barriers, avoiding
overflow of signed integers (other than via atomic_t), and fixing the
detection of batching.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This adds arch_remove_reservations(), which an arch can implement if it
needs to protect part of the address space from allocation.
Sometimes that can be done by just putting a region in the resource tree,
but there are cases where that doesn't work well. For example, x86 BIOS
E820 reservations are not related to devices, so they may overlap part of,
all of, or more than a device resource, so they may not end up at the
correct spot in the resource tree.
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Use this_cpu_inc_return in one place and avoid ugly __raw_get_cpu in
another.
V3->V4:
- Fix off by one.
V4-V4f:
- Use &listener_array
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
__get_cpu_var() can be replaced with this_cpu_read and will then use a
single read instruction with implied address calculation to access the
correct per cpu instance.
However, the address of a per cpu variable passed to __this_cpu_read()
cannot be determined (since it's an implied address conversion through
segment prefixes). Therefore apply this only to uses of __get_cpu_var
where the address of the variable is not used.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hughd@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Use this_cpu ops in various places to optimize per cpu data access.
Cc: Jason Baron <jbaron@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
tty: add 'active' sysfs attribute to tty0 and console device
Userspace can query the actual virtual console, and the configured
console devices behind /dev/tt0 and /dev/console.
The last entry in the list of devices is the active device, analog
to the console= kernel command line option.
The attribute supports poll(), which is raised when the virtual
console is changed or /dev/console is reconfigured.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
index 0000000..b138b66
Commit 3624eb0 (PM / Hibernate: Modify signature used to mark swap)
attempted to modify hibernate signature used to mark swap partitions
containing hibernation images, so that old kernels don't try to
handle compressed images. However, this change broke resume from
hibernation on Fedora 14 that apparently doesn't pass the resume=
argument to the kernel and tries to trigger resume from early user
space. This doesn't work, because the signature is now different,
so the old signature has to be restored to avoid the problem.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22732 .
Reported-by: Dr. David Alan Gilbert <linux@treblig.org>
Reported-by: Zhang Rui <rui.zhang@intel.com>
Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The user-space hibernation sends a wrong notification after the image
restoration because of thinko for the file flag check. RDONLY
corresponds to hibernation and WRONLY to restoration, confusingly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
Simple sysfs emumeration of the PMUs.
Use a "event_source" bus, and add PMU devices using their name.
Each PMU device has a type attribute which contrains the value needed
for perf_event_attr::type to identify this PMU.
This is the minimal stub needed to start using this interface,
we'll consider extending the sysfs usage later.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.316982569@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Extend the perf_pmu_register() interface to allow for named and
dynamic pmu types.
Because we need to support the existing static types we cannot use
dynamic types for everything, hence provide a type argument.
If we want to enumerate the PMUs they need a name, provide one.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.259707703@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently we call perf_event_init() from sched_init(). In order to
make it more obvious move it to the cannnonical location.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.093629821@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since the irqtime accounting is using non-atomic u64 and can be read
from remote cpus (writes are strictly cpu local, reads are not) we
have to deal with observing partial updates.
When we do observe partial updates the clock movement (in particular,
->clock_task movement) will go funny (in either direction), a
subsequent clock update (observing the full update) will make it go
funny in the oposite direction.
Since we rely on these clocks to be strictly monotonic we cannot
suffer backwards motion. One possible solution would be to simply
ignore all backwards deltas, but that will lead to accounting
artefacts, most notable: clock_task + irq_time != clock, this
inaccuracy would end up in user visible stats.
Therefore serialize the reads using a seqcount.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242434.6803.200.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some ARM systems have a short sched_clock() [ which needs to be fixed
too ], but this exposed a bug in the irq_time code as well, it doesn't
deal with wraps at all.
Fix the irq_time code to deal with u64 wraps by re-writing the code to
only use delta increments, which avoids the whole issue.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242433.6803.199.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The perf_swevent_enabled[] array has PERF_COUNT_SW_MAX elements.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101024195041.GT5985@bicker>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: It is likely that WORKER_NOT_RUNNING is true
MAINTAINERS: Add workqueue entry
workqueue: check the allocation of system_unbound_wq
If you try to build a kernel with KCONFIG_CONFIG set (to a value
not equal to .config) and that config sets CONFIG_IKCONFIG then the
build will fail with:
make[1]: *** No rule to make target `.config', needed by \
`kernel/config_data.gz'. Stop.
because the kernel/Makefile contains a direct reference to .config.
This issue has been present since the introduction of KCONFIG_CONFIG
in 14cdd3c402.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Roman Zippel <zippel@linux-m68k.org>
CC: Michal Marek <mmarek@suse.cz>
Reviewed-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Running the annotate branch profiler on three boxes, including my
main box that runs firefox, evolution, xchat, and is part of the distcc farm,
showed this with the likelys in the workqueue code:
correct incorrect % Function File Line
------- --------- - -------- ---- ----
96 996253 99 wq_worker_sleeping workqueue.c 703
96 996247 99 wq_worker_waking_up workqueue.c 677
The likely()s in this case were assuming that WORKER_NOT_RUNNING will
most likely be false. But this is not the case. The reason is
(and shown by adding trace_printks and testing it) that most of the time
WORKER_PREP is set.
In worker_thread() we have:
worker_clr_flags(worker, WORKER_PREP);
[ do work stuff ]
worker_set_flags(worker, WORKER_PREP, false);
(that 'false' means not to wake up an idle worker)
The wq_worker_sleeping() is called from schedule when a worker thread
is putting itself to sleep. Which happens most of the time outside
of that [ do work stuff ].
The wq_worker_waking_up is called by the wakeup worker code, which
is also callod outside that [ do work stuff ].
Thus, the likely and unlikely used by those two functions are actually
backwards.
Remove the annotation and let gcc figure it out.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
During suspend, we disable all the non boot cpus. And during resume we bring
them all back again. So no need to do alternatives_smp_switch() in between.
On my core 2 based laptop, this speeds up the suspend path by 15msec and the
resume path by 5 msec (suspend/resume speed up differences can be attributed
to the different P-states that the cpu is in during suspend/resume).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1290557500.4946.8.camel@sbsiddha-MOBL3.sc.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Eric asked for this.
[tglx: Because it generates faster code according to Erics ]
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-mm@kvack.org
LKML-Reference: <alpine.DEB.2.00.1011301404490.4039@router.home>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In converting the hrtimers to timerqueue, I missed
a spot in hrtimer_run_queues where we loop running
timers. We end up not pulling the new next value out
and instead just use the last next value, causing
boot time hangs in some cases.
The proper fix is to pull timerqueue_getnext each iteration
instead of using a local next value.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Linus Torvalds