Commit Graph

28399 Commits

Author SHA1 Message Date
Thomas Gleixner 9e90c79852 irqchip updates for 4.19
- GICv3 ITS LPI allocation revamp
 - GICv3 support for hypervisor-enforced LPI range
 - GICv3 ITS conversion to raw spinlock
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Merge tag 'irqchip-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

- GICv3 ITS LPI allocation revamp
- GICv3 support for hypervisor-enforced LPI range
- GICv3 ITS conversion to raw spinlock
2018-08-06 12:45:42 +02:00
Pingfan Liu 55f2503c3b PM / reboot: Eliminate race between reboot and suspend
At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-06 12:35:20 +02:00
Gustavo A. R. Silva 82837ad5bd PM / hibernate: Mark expected switch fall-through
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

This addresses Coverity-ID: 114713 ("Missing break in switch").

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-06 10:32:32 +02:00
Rafael J. Wysocki 6ccbe1dcdd Merge back cpufreq changes for 4.19. 2018-08-06 10:09:52 +02:00
Jens Axboe 05b9ba4b55 Linux 4.18-rc6
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Merge tag 'v4.18-rc6' into for-4.19/block2

Pull in 4.18-rc6 to get the NVMe core AEN change to avoid a
merge conflict down the line.

Signed-of-by: Jens Axboe <axboe@kernel.dk>
2018-08-05 19:32:09 -06:00
David S. Miller c1c8626fce Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
Lots of overlapping changes, mostly trivial in nature.

The mlxsw conflict was resolving using the example
resolution at:

https://github.com/jpirko/linux_mlxsw/blob/combined_queue/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05 13:04:31 -07:00
Prasad Sodagudi cfd355145c stop_machine: Atomically queue and wake stopper threads
When cpu_stop_queue_work() releases the lock for the stopper
thread that was queued into its wake queue, preemption is
enabled, which leads to the following deadlock:

CPU0                              CPU1
sched_setaffinity(0, ...)
__set_cpus_allowed_ptr()
stop_one_cpu(0, ...)              stop_two_cpus(0, 1, ...)
cpu_stop_queue_work(0, ...)       cpu_stop_queue_two_works(0, ..., 1, ...)

-grabs lock for migration/0-
                                  -spins with preemption disabled,
                                   waiting for migration/0's lock to be
                                   released-

-adds work items for migration/0
and queues migration/0 to its
wake_q-

-releases lock for migration/0
 and preemption is enabled-

-current thread is preempted,
and __set_cpus_allowed_ptr
has changed the thread's
cpu allowed mask to CPU1 only-

                                  -acquires migration/0 and migration/1's
                                   locks-

                                  -adds work for migration/0 but does not
                                   add migration/0 to wake_q, since it is
                                   already in a wake_q-

                                  -adds work for migration/1 and adds
                                   migration/1 to its wake_q-

                                  -releases migration/0 and migration/1's
                                   locks, wakes migration/1, and enables
                                   preemption-

                                  -since migration/1 is requested to run,
                                   migration/1 begins to run and waits on
                                   migration/0, but migration/0 will never
                                   be able to run, since the thread that
                                   can wake it is affine to CPU1-

Disable preemption in cpu_stop_queue_work() before queueing works for
stopper threads, and queueing the stopper thread in the wake queue, to
ensure that the operation of queueing the works and waking the stopper
threads is atomic.

Fixes: 0b26351b91 ("stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock")
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: matt@codeblueprint.co.uk
Cc: bigeasy@linutronix.de
Cc: gregkh@linuxfoundation.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1533329766-4856-1-git-send-email-isaacm@codeaurora.org

Co-Developed-by: Isaac J. Manjarres <isaacm@codeaurora.org>
2018-08-05 21:58:31 +02:00
Linus Torvalds 2f3672cbf9 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "Two oneliners addressing NOHZ failures:

   - Use a bitmask to check for the pending timer softirq and not the
     bit number. The existing code using the bit number checked for
     the wrong bit, which caused timers to either expire late or stop
     completely.

   - Make the nohz evaluation on interrupt exit more robust. The
     existing code did not re-arm the hardware when interrupting a
     running softirq in task context (ksoftirqd or tail of
     local_bh_enable()), which caused timers to either expire late
     or stop completely"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz: Fix missing tick reprogram when interrupting an inline softirq
  nohz: Fix local_timer_softirq_pending()
2018-08-05 09:25:29 -07:00
Thomas Gleixner f2701b77bb Merge 4.18-rc7 into master to pick up the KVM dependcy
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-08-05 16:39:29 +02:00
Eric W. Biederman 924de3b8c9 fork: Have new threads join on-going signal group stops
There are only two signals that are delivered to every member of a
signal group: SIGSTOP and SIGKILL.  Signal delivery requires every
signal appear to be delivered either before or after a clone syscall.
SIGKILL terminates the clone so does not need to be considered.  Which
leaves only SIGSTOP that needs to be considered when creating new
threads.

Today in the event of a group stop TIF_SIGPENDING will get set and the
fork will restart ensuring the fork syscall participates in the group
stop.

A fork (especially of a process with a lot of memory) is one of the
most expensive system so we really only want to restart a fork when
necessary.

It is easy so check to see if a SIGSTOP is ongoing and have the new
thread join it immediate after the clone completes.  Making it appear
the clone completed happened just before the SIGSTOP.

The calculate_sigpending function will see the bits set in jobctl and
set TIF_SIGPENDING to ensure the new task takes the slow path to userspace.

V2: The call to task_join_group_stop was moved before the new task is
    added to the thread group list.  This should not matter as
    sighand->siglock is held over both the addition of the threads,
    the call to task_join_group_stop and do_signal_stop.  But the change
    is trivial and it is one less thing to worry about when reading
    the code.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-08-03 20:20:14 -05:00
Eric W. Biederman 088fe47ce9 signal: Add calculate_sigpending()
Add a function calculate_sigpending to test to see if any signals are
pending for a new task immediately following fork.  Signals have to
happen either before or after fork.  Today our practice is to push
all of the signals to before the fork, but that has the downside that
frequent or periodic signals can make fork take much much longer than
normal or prevent fork from completing entirely.

So we need move signals that we can after the fork to prevent that.

This updates the code to set TIF_SIGPENDING on a new task if there
are signals or other activities that have moved so that they appear
to happen after the fork.

As the code today restarts if it sees any such activity this won't
immediately have an effect, as there will be no reason for it
to set TIF_SIGPENDING immediately after the fork.

Adding calculate_sigpending means the code in fork can safely be
changed to not always restart if a signal is pending.

The new calculate_sigpending function sets sigpending if there
are pending bits in jobctl, pending signals, the freezer needs
to freeze the new task or the live kernel patching framework
need the new thread to take the slow path to userspace.

I have verified that setting TIF_SIGPENDING does make a new process
take the slow path to userspace before it executes it's first userspace
instruction.

I have looked at the callers of signal_wake_up and the code paths
setting TIF_SIGPENDING and I don't see anything else that needs to be
handled.  The code probably doesn't need to set TIF_SIGPENDING for the
kernel live patching as it uses a separate thread flag as well.  But
at this point it seems safer reuse the recalc_sigpending logic and get
the kernel live patching folks to sort out their story later.

V2: I have moved the test into schedule_tail where siglock can
    be grabbed and recalc_sigpending can be reused directly.
    Further as the last action of setting up a new task this
    guarantees that TIF_SIGPENDING will be properly set in the
    new process.

    The helper calculate_sigpending takes the siglock and
    uncontitionally sets TIF_SIGPENDING and let's recalc_sigpending
    clear TIF_SIGPENDING if it is unnecessary.  This allows reusing
    the existing code and keeps maintenance of the conditions simple.

    Oleg Nesterov <oleg@redhat.com>  suggested the movement
    and pointed out the need to take siglock if this code
    was going to be called while the new task is discoverable.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-08-03 20:10:31 -05:00
Frederic Weisbecker 0a0e0829f9 nohz: Fix missing tick reprogram when interrupting an inline softirq
The full nohz tick is reprogrammed in irq_exit() only if the exit is not in
a nesting interrupt. This stands as an optimization: whether a hardirq or a
softirq is interrupted, the tick is going to be reprogrammed when necessary
at the end of the inner interrupt, with even potential new updates on the
timer queue.

When soft interrupts are interrupted, it's assumed that they are executing
on the tail of an interrupt return. In that case tick_nohz_irq_exit() is
called after softirq processing to take care of the tick reprogramming.

But the assumption is wrong: softirqs can be processed inline as well, ie:
outside of an interrupt, like in a call to local_bh_enable() or from
ksoftirqd.

Inline softirqs don't reprogram the tick once they are done, as opposed to
interrupt tail softirq processing. So if a tick interrupts an inline
softirq processing, the next timer will neither be reprogrammed from the
interrupting tick's irq_exit() nor after the interrupted softirq
processing. This situation may leave the tick unprogrammed while timers are
armed.

To fix this, simply keep reprogramming the tick even if a softirq has been
interrupted. That can be optimized further, but for now correctness is more
important.

Note that new timers enqueued in nohz_full mode after a softirq gets
interrupted will still be handled just fine through self-IPIs triggered by
the timer code.

Reported-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org # 4.14+
Link: https://lkml.kernel.org/r/1533303094-15855-1-git-send-email-frederic@kernel.org
2018-08-03 15:52:10 +02:00
Joel Fernandes (Google) da25a672cf trace: Use rcu_dereference_raw for hooks from trace-event subsystem
Since we switched to using SRCU for tracepoints used in the idle path,
we can no longer use rcu_dereference_sched for dereferencing points in
trace-event hooks.

Since tracepoints can now use either SRCU or sched-RCU, just use
rcu_dereference_raw for traceevents just like we're doing when
dereferencing the tracepoint table.

This prevents an RCU warning reported by Masami:

[  282.060593] WARNING: can't dereference registers at 00000000f3c7f62b
[  282.063200] =============================
[  282.064082] WARNING: suspicious RCU usage
[  282.064963] 4.18.0-rc6+ #15 Tainted: G        W
[  282.066048] -----------------------------
[  282.066923] /home/mhiramat/ksrc/linux/kernel/trace/trace_events.c:242
				suspicious rcu_dereference_check() usage!
[  282.068974]
[  282.068974] other info that might help us debug this:
[  282.068974]
[  282.070770]
[  282.070770] RCU used illegally from idle CPU!
[  282.070770] rcu_scheduler_active = 2, debug_locks = 1
[  282.072938] RCU used illegally from extended quiescent state!
[  282.074183] no locks held by swapper/0/0.
[  282.075071]
[  282.075071] stack backtrace:
[  282.076121] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W
[  282.077782] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
[  282.079604] Call Trace:
[  282.080212]  <IRQ>
[  282.080755]  dump_stack+0x85/0xcb
[  282.081523]  trace_event_ignore_this_pid+0x66/0x70
[  282.082541]  trace_event_raw_event_preemptirq_template+0xa2/0xb0
[  282.083774]  ? interrupt_entry+0xc4/0xe0
[  282.084665]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[  282.085669]  trace_hardirqs_off_caller+0x90/0xd0
[  282.086597]  trace_hardirqs_off_thunk+0x1a/0x1c
[  282.087433]  ? call_function_interrupt+0xa/0x20
[  282.088201]  interrupt_entry+0xc4/0xe0
[  282.088848]  ? call_function_interrupt+0xa/0x20
[  282.089579]  </IRQ>
[  282.090029]  ? native_safe_halt+0x2/0x10
[  282.090695]  ? default_idle+0x1f/0x160
[  282.091330]  ? default_idle_call+0x24/0x40
[  282.091997]  ? do_idle+0x210/0x250
[  282.092658]  ? cpu_startup_entry+0x6f/0x80
[  282.093338]  ? start_kernel+0x49d/0x4bd
[  282.093987]  ? secondary_startup_64+0xa5/0xb0

Link: http://lkml.kernel.org/r/20180803023407.225852-1-joel@joelfernandes.org

Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: e6753f23d9 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-03 09:38:39 -04:00
Thomas Gleixner d1f0301b33 genirq: Make force irq threading setup more robust
The support of force threading interrupts which are set up with both a
primary and a threaded handler wreckaged the setup of regular requested
threaded interrupts (primary handler == NULL).

The reason is that it does not check whether the primary handler is set to
the default handler which wakes the handler thread. Instead it replaces the
thread handler with the primary handler as it would do with force threaded
interrupts which have been requested via request_irq(). So both the primary
and the thread handler become the same which then triggers the warnon that
the thread handler tries to wakeup a not configured secondary thread.

Fortunately this only happens when the driver omits the IRQF_ONESHOT flag
when requesting the threaded interrupt, which is normaly caught by the
sanity checks when force irq threading is disabled.

Fix it by skipping the force threading setup when a regular threaded
interrupt is requested. As a consequence the interrupt request which lacks
the IRQ_ONESHOT flag is rejected correctly instead of silently wreckaging
it.

Fixes: 2a1d3ab898 ("genirq: Handle force threading of irqs with primary and thread handler")
Reported-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Cc: stable@vger.kernel.org
2018-08-03 15:19:01 +02:00
Sinan Kaya 1b6266ebe3 watchdog: Reduce message verbosity
Code is emitting the following error message during boot on systems
without PMU hardware support while probing NMI capability.

 NMI watchdog: Perf event create on CPU 0 failed with -2

This error is emitted as the perf subsystem returns -ENOENT due to lack of
PMUs in the system.

It is followed by the warning that NMI watchdog is disabled:

  NMI watchdog: Perf NMI watchdog permanently disabled

While NMI disabled information is useful for ordinary users, seeing a PERF
event create failed with error code -2 is not.

Reduce the message severity to debug so that if debugging is still possible
in case the error code returned by perf is required for analysis.

Signed-off-by: Sinan Kaya <okaya@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=599368
Link: https://lkml.kernel.org/r/20180803060943.2643-1-okaya@kernel.org
2018-08-03 12:19:08 +02:00
Palmer Dabbelt 4f7799d96e genirq/irqchip: Remove MULTI_IRQ_HANDLER as it's now obselete
Now that every user of MULTI_IRQ_HANDLER has been convereted over to use
GENERIC_IRQ_MULTI_HANDLER remove the references to MULTI_IRQ_HANDLER.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux@armlinux.org.uk
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: jonas@southpole.se
Cc: stefan.kristiansson@saunalahti.fi
Cc: shorne@gmail.com
Cc: jason@lakedaemon.net
Cc: marc.zyngier@arm.com
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: nicolas.pitre@linaro.org
Cc: vladimir.murzin@arm.com
Cc: keescook@chromium.org
Cc: jinb.park7@gmail.com
Cc: yamada.masahiro@socionext.com
Cc: alexandre.belloni@bootlin.com
Cc: pombredanne@nexb.com
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: kstewart@linuxfoundation.org
Cc: jhogan@kernel.org
Cc: mark.rutland@arm.com
Cc: ard.biesheuvel@linaro.org
Cc: james.morse@arm.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: openrisc@lists.librecores.org
Link: https://lkml.kernel.org/r/20180622170126.6308-6-palmer@sifive.com
2018-08-03 12:14:10 +02:00
Roman Gushchin cd33943176 bpf: introduce the bpf_get_local_storage() helper function
The bpf_get_local_storage() helper function is used
to get a pointer to the bpf local storage from a bpf program.

It takes a pointer to a storage map and flags as arguments.
Right now it accepts only cgroup storage maps, and flags
argument has to be 0. Further it can be extended to support
other types of local storage: e.g. thread local storage etc.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin 7b5dd2bde7 bpf: don't allow create maps of cgroup local storages
As there is one-to-one relation between a bpf program
and cgroup local storage map, there is no sense in
creating a map of cgroup local storage maps.

Forbid it explicitly to avoid possible side effects.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin 3e6a4b3e02 bpf/verifier: introduce BPF_PTR_TO_MAP_VALUE
BPF_MAP_TYPE_CGROUP_STORAGE maps are special in a way
that the access from the bpf program side is lookup-free.
That means the result is guaranteed to be a valid
pointer to the cgroup storage; no NULL-check is required.

This patch introduces BPF_PTR_TO_MAP_VALUE return type,
which is required to cause the verifier accept programs,
which are not checking the map value pointer for being NULL.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin 394e40a297 bpf: extend bpf_prog_array to store pointers to the cgroup storage
This patch converts bpf_prog_array from an array of prog pointers
to the array of struct bpf_prog_array_item elements.

This allows to save a cgroup storage pointer for each bpf program
efficiently attached to a cgroup.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin d7bf2c10af bpf: allocate cgroup storage entries on attaching bpf programs
If a bpf program is using cgroup local storage, allocate
a bpf_cgroup_storage structure automatically on attaching the program
to a cgroup and save the pointer into the corresponding bpf_prog_list
entry.
Analogically, release the cgroup local storage on detaching
of the bpf program.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin aa0ad5b039 bpf: pass a pointer to a cgroup storage using pcpu variable
This commit introduces the bpf_cgroup_storage_set() helper,
which will be used to pass a pointer to a cgroup storage
to the bpf helper.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin de9cbbaadb bpf: introduce cgroup storage maps
This commit introduces BPF_MAP_TYPE_CGROUP_STORAGE maps:
a special type of maps which are implementing the cgroup storage.

>From the userspace point of view it's almost a generic
hash map with the (cgroup inode id, attachment type) pair
used as a key.

The only difference is that some operations are restricted:
  1) a user can't create new entries,
  2) a user can't remove existing entries.

The lookup from userspace is o(log(n)).

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:32 +02:00
Roman Gushchin 0a4c58f570 bpf: add ability to charge bpf maps memory dynamically
This commits extends existing bpf maps memory charging API
to support dynamic charging/uncharging.

This is required to account memory used by maps,
if all entries are created dynamically after
the map initialization.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-03 00:47:31 +02:00
David S. Miller 89b1698c93 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
The BTF conflicts were simple overlapping changes.

The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 10:55:32 -07:00
Masami Hiramatsu 6bc6c77cfc tracing/kprobes: Fix within_notrace_func() to check only notrace functions
Fix within_notrace_func() to check only notrace functions and to ignore the
kprobe-event which can not solve symbol addresses.

within_notrace_func() returns true if the given kprobe events probe point
seems to be out-of-range. But that is not the correct place to check for it,
it should be done in kprobes afterwards.

kprobe-events allow users to define a probe point on "currently unloaded
module" so that it can trace the event during module load. In this case, the
user will put a probe on a symbol which is not in kallsyms yet and it hits
the within_notrace_func().  As a result, kprobe-events always refuses if
user defines a probe on a "currenly unloaded module".

Fixes: commit 45408c4f92 ("tracing: kprobes: Prohibit probing on notrace function")
Link: http://lkml.kernel.org/r/153319624799.29007.13604430345640129926.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-02 12:34:41 -04:00
zhong jiang 9be936f4b3 kernel/module: Use kmemdup to replace kmalloc+memcpy
we prefer to the kmemdup rather than kmalloc+memcpy. so just
replace them.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-08-02 18:03:17 +02:00
Peter Zijlstra b80a2bfce8 stop_machine: Reflow cpu_stop_queue_two_works()
The code flow in cpu_stop_queue_two_works() is a little arcane; fix this by
lifting the preempt_disable() to the top to create more natural nesting wrt
the spinlocks and make the wake_up_q() and preempt_enable() unconditional
at the end.

Furthermore, enable preemption in the -EDEADLK case, such that we spin-wait
with preemption enabled.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: isaacm@codeaurora.org
Cc: matt@codeblueprint.co.uk
Cc: psodagud@codeaurora.org
Cc: gregkh@linuxfoundation.org
Cc: pkondeti@codeaurora.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180730112140.GH2494@hirez.programming.kicks-ass.net
2018-08-02 15:25:20 +02:00
Sudeep Holla fbfa926008 clockevents: Warn if cpu_all_mask is used as cpumask
Using cpu_all_mask in clockevents cpumask may result in issues while
comparing multiple clockevent devices to choose the preferred one.

On one of the platforms with 2 system (i.e. non per-CPU) timers with
different ratings, having cpu_all_mask for one of the device resulted in a
boot hang due to a endless loop in clockevents_notify_released() as both
were clocksources were selected as preferred.

In order to prevent such issues in the future, warn if any clockevent
driver sets cpu_all_mask as it's cpumask and just override it to use
cpu_possible_mask. All the existing occurrences of cpu_all_mask are already
replaced with cpu_possible_mask.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/1531308264-24220-3-git-send-email-sudeep.holla@arm.com
2018-08-02 14:55:53 +02:00
Sudeep Holla 234b3840d7 tick/broadcast-hrtimer: Use cpu_possible_mask for ce_broadcast_hrtimer
This is the last instance of cpu_all_mask usage in the core framework.

Replace it with cpu_possible_mask like all other instances in the
clockevent drivers. This makes it possible to add a warning in the core
clockevents_register_device on usage of cpu_all_mask from any clockevent
drivers in the future.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/1531308264-24220-2-git-send-email-sudeep.holla@arm.com
2018-08-02 14:55:52 +02:00
Gaurav Kohli 363e934d88 timers: Clear timer_base::must_forward_clk with timer_base::lock held
timer_base::must_forward_clock is indicating that the base clock might be
stale due to a long idle sleep.

The forwarding of the base clock takes place in the timer softirq or when a
timer is enqueued to a base which is idle. If the enqueue of timer to an
idle base happens from a remote CPU, then the following race can happen:

  CPU0					CPU1
  run_timer_softirq			mod_timer

					base = lock_timer_base(timer);
  base->must_forward_clk = false
					if (base->must_forward_clk)
				       	    forward(base); -> skipped

					enqueue_timer(base, timer, idx);
					-> idx is calculated high due to
					   stale base
					unlock_timer_base(timer);
  base = lock_timer_base(timer);
  forward(base);

The root cause is that timer_base::must_forward_clk is cleared outside the
timer_base::lock held region, so the remote queuing CPU observes it as
cleared, but the base clock is still stale. This can cause large
granularity values for timers, i.e. the accuracy of the expiry time
suffers.

Prevent this by clearing the flag with timer_base::lock held, so that the
forwarding takes place before the cleared flag is observable by a remote
CPU.

Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: linux-arm-msm@vger.kernel.org
Link: https://lkml.kernel.org/r/1533199863-22748-1-git-send-email-gkohli@codeaurora.org
2018-08-02 12:52:38 +02:00
Ingo Molnar 16e0e6a83b Merge branch 'perf/urgent' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-08-02 09:59:20 +02:00
Gustavo A. R. Silva 44ec3ec01f ftrace: Use true and false for boolean values in ops_references_rec()
Return statements in functions returning bool should use true or false
instead of an integer value.

This code was detected with the help of Coccinelle.

Link: http://lkml.kernel.org/r/20180802010056.GA31012@embeddedor.com

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 21:15:31 -04:00
Steven Rostedt (VMware) d7224c0e12 ring-buffer: Make ring_buffer_record_is_set_on() return bool
The value of ring_buffer_record_is_set_on() is either true or false, so have
its return value be bool.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 21:09:50 -04:00
Steven Rostedt (VMware) 3ebea280d7 ring-buffer: Make ring_buffer_record_is_on() return bool
The value of ring_buffer_record_is_on() is either true or false, so have its
return value be bool.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 21:08:30 -04:00
Christoph Hellwig 87a4c37599 kconfig: include kernel/Kconfig.preempt from init/Kconfig
Almost all architectures include it.  Add a ARCH_NO_PREEMPT symbol to
disable preempt support for alpha, hexagon, non-coldfire m68k and
user mode Linux.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-02 08:06:54 +09:00
Steven Rostedt (VMware) ec57350883 tracing: Make tracer_tracing_is_on() return bool
There's code that expects tracer_tracing_is_on() to be either true or false,
not some random number. Currently, it should only return one or zero, but
just in case, change its return value to bool, to enforce it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 16:08:57 -04:00
Steven Rostedt (VMware) 978defee11 tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists
The start function of the hwlat tracer should never be called when the hwlat
thread already exists. If it is called, do a WARN_ON().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 16:06:02 -04:00
Erica Bugden 82fbc8c48a ftrace: Add missing check for existing hwlat thread
The hwlat tracer uses a kernel thread to measure latencies. The function
that creates this kernel thread, start_kthread(), can be called when the
tracer is initialized and when the tracer is explicitly enabled.
start_kthread() does not check if there is an existing hwlat kernel
thread and will create a new one each time it is called.

This causes the reference to the previous thread to be lost. Without the
thread reference, the old kernel thread becomes unstoppable and
continues to use CPU time even after the hwlat tracer has been disabled.
This problem can be observed when a system is booted with tracing
enabled and the hwlat tracer is configured like this:

	echo hwlat > current_tracer; echo 1 > tracing_on

Add the missing check for an existing kernel thread in start_kthread()
to prevent this problem. This function and the rest of the hwlat kernel
thread setup and teardown are already serialized because they are called
through the tracer core code with trace_type_lock held.

[
 Note, this only fixes the symptom. The real fix was not to call
 this function when tracing_on was already one. But this still makes
 the code more robust, so we'll add it.
]

Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de

Signed-off-by: Erica Bugden <erica.bugden@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 16:04:24 -04:00
Steven Rostedt (VMware) f143641bfe tracing: Do not call start/stop() functions when tracing_on does not change
Currently, when one echo's in 1 into tracing_on, the current tracer's
"start()" function is executed, even if tracing_on was already one. This can
lead to strange side effects. One being that if the hwlat tracer is enabled,
and someone does "echo 1 > tracing_on" into tracing_on, the hwlat tracer's
start() function is called again which will recreate another kernel thread,
and make it unable to remove the old one.

Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de

Cc: stable@vger.kernel.org
Fixes: 2df8f8a6a8 ("tracing: Fix regression with irqsoff tracer and tracing_on file")
Reported-by: Erica Bugden <erica.bugden@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-01 16:01:02 -04:00
Josef Bacik 2c323017e3 blk-cgroup: clear the throttle queue on fork
We were hitting a panic in production where we put too many times on the
request queue.  This is because we'd get the throttle_queue of the
parent if we fork()'ed while we needed to be throttled, but we didn't
have a reference on it.  Instead just clear these flags on fork so the
child doesn't pay for the sins of its father.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-01 09:16:04 -06:00
Linus Torvalds 37b71411b7 audit/stable-4.18 PR 20180731
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Merge tag 'audit-pr-20180731' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit fix from Paul Moore:
 "A single small audit fix to guard against memory allocation failures
  when logging information about a kernel module load.

  It's small, easy to understand, and self-contained; while nothing is
  zero risk, this should be pretty low"

* tag 'audit-pr-20180731' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: fix potential null dereference 'context->module.name'
2018-07-31 13:17:46 -07:00
Arthur Fabre fbeb1603bf bpf: verifier: MOV64 don't mark dst reg unbounded
When check_alu_op() handles a BPF_MOV64 between two registers,
it calls check_reg_arg(DST_OP) on the dst register, marking it
as unbounded. If the src and dst register are the same, this
marks the src as unbounded, which can lead to unexpected errors
for further checks that rely on bounds info. For example:

	BPF_MOV64_IMM(BPF_REG_2, 0),
	BPF_MOV64_REG(BPF_REG_2, BPF_REG_2),
	BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2),
	BPF_MOV64_IMM(BPF_REG_0, 0),
	BPF_EXIT_INSN(),

Results in:

	"math between ctx pointer and register with unbounded
	min value is not allowed"

check_alu_op() now uses check_reg_arg(DST_OP_NO_MARK), and MOVs
that need to mark the dst register (MOVIMM, MOV32) do so.

Added a test case for MOV64 dst == src, and dst != src.

Signed-off-by: Arthur Fabre <afabre@cloudflare.com>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-31 22:09:33 +02:00
Anna-Maria Gleixner 80d20d35af nohz: Fix local_timer_softirq_pending()
local_timer_softirq_pending() checks whether the timer softirq is
pending with: local_softirq_pending() & TIMER_SOFTIRQ.

This is wrong because TIMER_SOFTIRQ is the softirq number and not a
bitmask. So the test checks for the wrong bit.

Use BIT(TIMER_SOFTIRQ) instead.

Fixes: 5d62c183f9 ("nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()")
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Cc: bigeasy@linutronix.de
Cc: peterz@infradead.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180731161358.29472-1-anna-maria@linutronix.de
2018-07-31 22:08:44 +02:00
Joel Fernandes (Google) c3bc8fd637 tracing: Centralize preemptirq tracepoints and unify their usage
This patch detaches the preemptirq tracepoints from the tracers and
keeps it separate.

Advantages:
* Lockdep and irqsoff event can now run in parallel since they no longer
have their own calls.

* This unifies the usecase of adding hooks to an irqsoff and irqson
event, and a preemptoff and preempton event.
  3 users of the events exist:
  - Lockdep
  - irqsoff and preemptoff tracers
  - irqs and preempt trace events

The unification cleans up several ifdefs and makes the code in preempt
tracer and irqsoff tracers simpler. It gets rid of all the horrific
ifdeferry around PROVE_LOCKING and makes configuration of the different
users of the tracepoints more easy and understandable. It also gets rid
of the time_* function calls from the lockdep hooks used to call into
the preemptirq tracer which is not needed anymore. The negative delta in
lines of code in this patch is quite large too.

In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS
as a single point for registering probes onto the tracepoints. With
this,
the web of config options for preempt/irq toggle tracepoints and its
users becomes:

 PREEMPT_TRACER   PREEMPTIRQ_EVENTS  IRQSOFF_TRACER PROVE_LOCKING
       |                 |     \         |           |
       \    (selects)    /      \        \ (selects) /
      TRACE_PREEMPT_TOGGLE       ----> TRACE_IRQFLAGS
                      \                  /
                       \ (depends on)   /
                     PREEMPTIRQ_TRACEPOINTS

Other than the performance tests mentioned in the previous patch, I also
ran the locking API test suite. I verified that all tests cases are
passing.

I also injected issues by not registering lockdep probes onto the
tracepoints and I see failures to confirm that the probes are indeed
working.

This series + lockdep probes not registered (just to inject errors):
[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |

With this series + lockdep probes registered, all locking tests pass:

[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |

Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.org

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-31 11:32:27 -04:00
Thomas Zimmermann 56e6c104e4 console: Replace #if 0 with atomic var 'ignore_console_lock_warning'
The macro WARN_CONSOLE_UNLOCKED prints a warning when a thread enters
the console's critical section without having acquired the console
lock. The console lock can be ignored when debugging the console using
printk, but this makes WARN_CONSOLE_UNLOCKED generate unnecessary
warnings.

The variable ignore_console_lock_warning temporarily disables
WARN_CONSOLE_UNLOCKED. Developers interested in debugging the console's
critical sections should increment it before entering the CS and
decrement it after leaving the CS. Setting ignore_console_lock_warning
is only for debugging. Regular operation should not manipulate it.

Acknoledgements: This patch is based on an earlier version by Steven
Rostedt. The use of atomic increment/decrement was suggested by Petr
Mladek.

Link: http://lkml.kernel.org/r/717e6337-e7a6-7a92-1c1b-8929a25696b5@suse.de
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
[b.zolnierkie: use <linux/atomic.h>]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2018-07-31 13:06:57 +02:00
Michael O'Farrell 9d2dcc8fc6 arm64: perf: Add cap_user_time aarch64
It is useful to get the running time of a thread.  Doing so in an
efficient manner can be important for performance of user applications.
Avoiding system calls in `clock_gettime` when handling
CLOCK_THREAD_CPUTIME_ID is important.  Other clocks are handled in the
VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call.

CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have
costs associated with maintaining updated user space accessible time
offsets.  These offsets have to be updated everytime the a thread is
scheduled/descheduled.  However, for programs regularly checking the
running time of a thread, this is a performance improvement.

This patch takes a middle ground, and adds support for cap_user_time an
optional feature of the perf_event API.  This way costs are only
incurred when the perf_event api is enabled.  This is done the same way
as it is in x86.

Ultimately this allows calculating the thread running time in userspace
on aarch64 as follows (adapted from perf_event_open manpage):

u32 seq, time_mult, time_shift;
u64 running, count, time_offset, quot, rem, delta;
struct perf_event_mmap_page *pc;
pc = buf;  // buf is the perf event mmaped page as documented in the API.

if (pc->cap_usr_time) {
    do {
        seq = pc->lock;
        barrier();
        running = pc->time_running;

        count = readCNTVCT_EL0();  // Read ARM hardware clock.
        time_offset = pc->time_offset;
        time_mult   = pc->time_mult;
        time_shift  = pc->time_shift;

        barrier();
    } while (pc->lock != seq);

    quot = (count >> time_shift);
    rem = count & (((u64)1 << time_shift) - 1);
    delta = time_offset + quot * time_mult +
            ((rem * time_mult) >> time_shift);

    running += delta;
    // running now has the current nanosecond level thread time.
}

Summary of changes in the patch:

For aarch64 systems, make arch_perf_update_userpage update the timing
information stored in the perf_event page.  Requiring the following
calculations:
  - Calculate the appropriate time_mult, and time_shift factors to convert
    ticks to nano seconds for the current clock frequency.
  - Adjust the mult and shift factors to avoid shift factors of 32 bits.
    (possibly unnecessary)
  - The time_offset userspace should apply when doing calculations:
    negative the current sched time (now), because time_running and
    time_enabled fields of the perf_event page have just been updated.
Toggle bits to appropriate values:
  - Enable cap_user_time

Signed-off-by: Michael O'Farrell <micpof@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-31 10:14:00 +01:00
Linus Torvalds f67077deb4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Several smallish fixes, I don't think any of this requires another -rc
  but I'll leave that up to you:

   1) Don't leak uninitialzed bytes to userspace in xfrm_user, from Eric
      Dumazet.

   2) Route leak in xfrm_lookup_route(), from Tommi Rantala.

   3) Premature poll() returns in AF_XDP, from Björn Töpel.

   4) devlink leak in netdevsim, from Jakub Kicinski.

   5) Don't BUG_ON in fib_compute_spec_dst, the condition can
      legitimately happen. From Lorenzo Bianconi.

   6) Fix some spectre v1 gadgets in generic socket code, from Jeremy
      Cline.

   7) Don't allow user to bind to out of range multicast groups, from
      Dmitry Safonov with a follow-up by Dmitry Safonov.

   8) Fix metrics leak in fib6_drop_pcpu_from(), from Sabrina Dubroca"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (41 commits)
  netlink: Don't shift with UB on nlk->ngroups
  net/ipv6: fix metrics leak
  xen-netfront: wait xenbus state change when load module manually
  can: ems_usb: Fix memory leak on ems_usb_disconnect()
  openvswitch: meter: Fix setting meter id for new entries
  netlink: Do not subscribe to non-existent groups
  NET: stmmac: align DMA stuff to largest cache line length
  tcp_bbr: fix bw probing to raise in-flight data for very small BDPs
  net: socket: Fix potential spectre v1 gadget in sock_is_registered
  net: socket: fix potential spectre v1 gadget in socketcall
  net: mdio-mux: bcm-iproc: fix wrong getter and setter pair
  ipv4: remove BUG_ON() from fib_compute_spec_dst
  enic: handle mtu change for vf properly
  net: lan78xx: fix rx handling before first packet is send
  nfp: flower: fix port metadata conversion bug
  bpf: use GFP_ATOMIC instead of GFP_KERNEL in bpf_parse_prog()
  bpf: fix bpf_skb_load_bytes_relative pkt length check
  perf build: Build error in libbpf missing initialization
  net: ena: Fix use of uninitialized DMA address bits field
  bpf: btf: Use exact btf value_size match in map_check_btf()
  ...
2018-07-30 21:40:37 -07:00
Joel Fernandes (Google) e6753f23d9 tracepoint: Make rcuidle tracepoint callers use SRCU
In recent tests with IRQ on/off tracepoints, a large performance
overhead ~10% is noticed when running hackbench. This is root caused to
calls to rcu_irq_enter_irqson and rcu_irq_exit_irqson from the
tracepoint code. Following a long discussion on the list [1] about this,
we concluded that srcu is a better alternative for use during rcu idle.
Although it does involve extra barriers, its lighter than the sched-rcu
version which has to do additional RCU calls to notify RCU idle about
entry into RCU sections.

In this patch, we change the underlying implementation of the
trace_*_rcuidle API to use SRCU. This has shown to improve performance
alot for the high frequency irq enable/disable tracepoints.

Test: Tested idle and preempt/irq tracepoints.

Here are some performance numbers:

With a run of the following 30 times on a single core x86 Qemu instance
with 1GB memory:
hackbench -g 4 -f 2 -l 3000

Completion times in seconds. CONFIG_PROVE_LOCKING=y.

No patches (without this series)
Mean: 3.048
Median: 3.025
Std Dev: 0.064

With Lockdep using irq tracepoints with RCU implementation:
Mean: 3.451   (-11.66 %)
Median: 3.447 (-12.22%)
Std Dev: 0.049

With Lockdep using irq tracepoints with SRCU implementation (this series):
Mean: 3.020   (I would consider the improvement against the "without
	       this series" case as just noise).
Median: 3.013
Std Dev: 0.033

[1] https://patchwork.kernel.org/patch/10344297/

[remove rcu_read_lock_sched_notrace as its the equivalent of
preempt_disable_notrace and is unnecessary to call in tracepoint code]
Link: http://lkml.kernel.org/r/20180730222423.196630-3-joel@joelfernandes.org

Cleaned-up-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ Simplified WARN_ON_ONCE() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-30 19:13:03 -04:00
Joel Fernandes (Google) 01f38497c6 lockdep: Use this_cpu_ptr instead of get_cpu_var stats
get_cpu_var disables preemption which has the potential to call into the
preemption disable trace points causing some complications. There's also
no need to disable preemption in uses of get_lock_stats anyway since
preempt is already disabled. So lets simplify the code.

Link: http://lkml.kernel.org/r/20180730222423.196630-2-joel@joelfernandes.org

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-30 19:06:54 -04:00
Francis Deslauriers d899926f55 selftest/ftrace: Move kprobe selftest function to separate compile unit
Move selftest function to its own compile unit so it can be compiled
with the ftrace cflags (CC_FLAGS_FTRACE) allowing it to be probed
during the ftrace startup tests.

Link: http://lkml.kernel.org/r/153294604271.32740.16490677128630177030.stgit@devbox

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-30 18:41:04 -04:00
Masami Hiramatsu 45408c4f92 tracing: kprobes: Prohibit probing on notrace function
Prohibit kprobe-events probing on notrace functions.  Since probing on a
notrace function can cause a recursive event call. In most cases those are just
skipped, but in some cases it falls into an infinite recursive call.

This protection can be disabled by the kconfig
CONFIG_KPROBE_EVENTS_ON_NOTRACE=y, but it is highly recommended to keep it
"n" for normal kernel builds.  Note that this is only available if "kprobes on
ftrace" has been implemented on the target arch and CONFIG_KPROBES_ON_FTRACE=y.

Link: http://lkml.kernel.org/r/153294601436.32740.10557881188933661239.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Francis Deslauriers <francis.deslauriers@efficios.com>
[ Slight grammar and spelling fixes ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-30 18:28:52 -04:00
Yi Wang b305f7ed0f audit: fix potential null dereference 'context->module.name'
The variable 'context->module.name' may be null pointer when
kmalloc return null, so it's better to check it before using
to avoid null dereference.
Another one more thing this patch does is using kstrdup instead
of (kmalloc + strcpy), and signal a lost record via audit_log_lost.

Cc: stable@vger.kernel.org # 4.11
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-07-30 18:09:37 -04:00
Mukesh Ojha d018031f56 cpu/hotplug: Clarify CPU hotplug step name for timers
After commit 249d4a9b3246 ("timers: Reinitialize per cpu bases on hotplug")
i.e. the introduction of state CPUHP_TIMERS_PREPARE instead of
CPUHP_TIMERS_DEAD the step name "timers:dead" is not longer accurate.

Rename it to "timers:prepare".

[ tglx: Massaged changelog ]

Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gkohli@codeaurora.org
Cc: neeraju@codeaurora.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Brendan Jackman <brendan.jackman@arm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Link: https://lkml.kernel.org/r/1532443668-26810-1-git-send-email-mojha@codeaurora.org
2018-07-30 21:30:52 +02:00
Linus Torvalds ae3e10aba5 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Misc fixes:

   - a deadline scheduler related bug fix which triggered a kernel
     warning

   - an RT_RUNTIME_SHARE fix

   - a stop_machine preemption fix

   - a potential NULL dereference fix in sched_domain_debug_one()"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt: Restore rt_runtime after disabling RT_RUNTIME_SHARE
  sched/deadline: Update rq_clock of later_rq when pushing a task
  stop_machine: Disable preemption after queueing stopper threads
  sched/topology: Check variable group before dereferencing it
2018-07-30 12:13:56 -07:00
Linus Torvalds 0634922a78 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Misc fixes:

   - AMD IBS data corruptor fix (uncovered by UBSAN)

   - an Intel PEBS entry unwind error fix

   - a HW-tracing crash fix

   - a MAINTAINERS update"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix crash when using HW tracing kernel filters
  perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)
  MAINTAINERS: Add Naveen N. Rao as kprobes co-maintainer
  perf/x86/amd/ibs: Don't access non-started event
2018-07-30 11:45:30 -07:00
Linus Torvalds fb20c03d37 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "A paravirt UP-patching fix, and an I2C MUX driver lockdep warning fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/pvqspinlock/x86: Use LOCK_PREFIX in __pv_queued_spin_unlock() assembly code
  i2c/mux, locking/core: Annotate the nested rt_mutex usage
  locking/rtmutex: Allow specifying a subclass for nested locking
2018-07-30 11:37:16 -07:00
Pavel Tatashin bd9f943e5d sched/clock: Disable interrupts when calling generic_sched_clock_init()
sched_clock_init() used be called early during boot when interrupts were
still disabled. After the recent changes to utilize sched clock early the
sched_clock_init() call happens when interrupts are already enabled, which
triggers the following warning:

WARNING: CPU: 0 PID: 0 at kernel/time/sched_clock.c:180 sched_clock_register+0x44/0x278
[<c001a13c>] (warn_slowpath_null) from [<c052367c>] (sched_clock_register+0x44/0x278)
[<c052367c>] (sched_clock_register) from [<c05238d8>] (generic_sched_clock_init+0x28/0x88)
[<c05238d8>] (generic_sched_clock_init) from [<c0521a00>] (sched_clock_init+0x54/0x74)
[<c0521a00>] (sched_clock_init) from [<c0519c18>] (start_kernel+0x310/0x3e4)
[<c0519c18>] (start_kernel) from [<00000000>] (  (null))

Disable IRQs for the duration of generic_sched_clock_init().

Fixes: 857baa87b6 ("sched/clock: Enable sched clock early")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Link: https://lkml.kernel.org/r/20180730135252.24599-1-pasha.tatashin@oracle.com
2018-07-30 19:33:35 +02:00
Pavel Tatashin 684ad537ab timekeeping: Prevent false warning when persistent clock is not available
On arches with no persistent clock a message like this is printed during
boot:

[    0.000000] Persistent clock returned invalid value

The value is not invalid: Zero means that no persistent clock is available
and the absence of persistent clock should be quietly accepted.

Fixes: 3eca993740 ("timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: sboyd@kernel.org
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/20180725200018.23722-1-pasha.tatashin@oracle.com
2018-07-30 19:32:29 +02:00
Rafael J. Wysocki 5a4c996764 Merge back cpufreq material for 4.19. 2018-07-30 11:27:01 +02:00
Dave Airlie 3fce461827 BackMerge v4.18-rc7 into drm-next
rmk requested this for armada and I think we've had a few
conflicts build up.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2018-07-30 10:39:22 +10:00
David S. Miller 958b4cd8fa Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2018-07-28

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) API fixes for libbpf's BTF mapping of map key/value types in order
   to make them compatible with iproute2's BPF_ANNOTATE_KV_PAIR()
   markings, from Martin.

2) Fix AF_XDP to not report POLLIN prematurely by using the non-cached
   consumer pointer of the RX queue, from Björn.

3) Fix __xdp_return() to check for NULL pointer after the rhashtable
   lookup that retrieves the allocator object, from Taehee.

4) Fix x86-32 JIT to adjust ebp register in prologue and epilogue
   by 4 bytes which got removed from overall stack usage, from Wang.

5) Fix bpf_skb_load_bytes_relative() length check to use actual
   packet length, from Daniel.

6) Fix uninitialized return code in libbpf bpf_perf_event_read_simple()
   handler, from Thomas.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-28 21:02:21 -07:00
kbuild test robot 518eeca05c tracing: preemptirq_delay_run() can be static
Automatically found by kbuild test robot.

Fixes: ffdc73a3b2ad ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Signed-off-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-27 17:58:34 -04:00
Linus Torvalds 864af0d40c Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kvm, mm: account shadow page tables to kmemcg
  zswap: re-check zswap_is_full() after do zswap_shrink()
  include/linux/eventfd.h: include linux/errno.h
  mm: fix vma_is_anonymous() false-positives
  mm: use vma_init() to initialize VMAs on stack and data segments
  mm: introduce vma_init()
  mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL
  ipc/sem.c: prevent queue.status tearing in semop
  mm: disallow mappings that conflict for devm_memremap_pages()
  kasan: only select SLUB_DEBUG with SYSFS=y
  delayacct: fix crash in delayacct_blkio_end() after delayacct init failure
2018-07-27 10:30:47 -07:00
Robin Murphy f07d141fe9 dma-mapping: Generalise dma_32bit_limit flag
Whilst the notion of an upstream DMA restriction is most commonly seen
in PCI host bridges saddled with a 32-bit native interface, a more
general version of the same issue can exist on complex SoCs where a bus
or point-to-point interconnect link from a device's DMA master interface
to another component along the path to memory (often an IOMMU) may carry
fewer address bits than the interfaces at both ends nominally support.
In order to properly deal with this, the first step is to expand the
dma_32bit_limit flag into an arbitrary mask.

To minimise the impact on existing code, we'll make sure to only
consider this new mask valid if set. That makes sense anyway, since a
mask of zero would represent DMA not being wired up at all, and that
would be better handled by not providing valid ops in the first place.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-07-27 19:01:04 +02:00
Linus Torvalds 3ebb6fb03d Various fixes to the tracing infrastructure:
- Fix double free when the reg() call fails in event_trigger_callback()
 
  - Fix anomoly of snapshot causing tracing_on flag to change
 
  - Add selftest to test snapshot and tracing_on affecting each other
 
  - Fix setting of tracepoint flag on error that prevents probes from
    being deleted.
 
  - Fix another possible double free that is similar to event_trigger_callback()
 
  - Quiet a gcc warning of a false positive unused variable
 
  - Fix crash of partial exposed task->comm to trace events
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Merge tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various fixes to the tracing infrastructure:

   - Fix double free when the reg() call fails in
     event_trigger_callback()

   - Fix anomoly of snapshot causing tracing_on flag to change

   - Add selftest to test snapshot and tracing_on affecting each other

   - Fix setting of tracepoint flag on error that prevents probes from
     being deleted.

   - Fix another possible double free that is similar to
     event_trigger_callback()

   - Quiet a gcc warning of a false positive unused variable

   - Fix crash of partial exposed task->comm to trace events"

* tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kthread, tracing: Don't expose half-written comm when creating kthreads
  tracing: Quiet gcc warning about maybe unused link variable
  tracing: Fix possible double free in event_enable_trigger_func()
  tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
  selftests/ftrace: Add snapshot and tracing_on test case
  ring_buffer: tracing: Inherit the tracing setting to next ring buffer
  tracing: Fix double free of event_trigger_data
2018-07-27 09:50:33 -07:00
Steven Rostedt (VMware) 87107a25a2 tracing/kprobes: Simplify the logic of enable_trace_kprobe()
The function enable_trace_kprobe() performs slightly differently if the file
parameter is passed in as NULL on non-NULL. Instead of checking file twice,
move the code between the two tests into a static inline helper function to
make the code easier to follow.

Link: http://lkml.kernel.org/r/20180725224728.7b1d5db2@vmware.local.home
Link: http://lkml.kernel.org/r/20180726121152.4dd54330@gandalf.local.home

Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-27 09:36:20 -04:00
Kirill A. Shutemov 027232da7c mm: introduce vma_init()
Not all VMAs allocated with vm_area_alloc().  Some of them allocated on
stack or in data segment.

The new helper can be use to initialize VMA properly regardless where it
was allocated.

Link: http://lkml.kernel.org/r/20180724121139.62570-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Dan Williams 31c5bda3a6 mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL
Commit e763848843 ("mm: introduce MEMORY_DEVICE_FS_DAX and
CONFIG_DEV_PAGEMAP_OPS") added two EXPORT_SYMBOL_GPL() symbols, but
these symbols are required by the inlined put_page(), thus accidentally
making put_page() a GPL export only.  This breaks OpenAFS (at least).

Mark them EXPORT_SYMBOL() instead.

Link: http://lkml.kernel.org/r/153128611970.2928.11310692420711601254.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: e763848843 ("mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Joe Gorse <jhgorse@gmail.com>
Reported-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Joe Gorse <jhgorse@gmail.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Mark Vitale <mvitale@sinenomine.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Dave Jiang 15d36fecd0 mm: disallow mappings that conflict for devm_memremap_pages()
When pmem namespaces created are smaller than section size, this can
cause an issue during removal and gpf was observed:

  general protection fault: 0000 1 SMP PTI
  CPU: 36 PID: 3941 Comm: ndctl Tainted: G W 4.14.28-1.el7uek.x86_64 #2
  task: ffff88acda150000 task.stack: ffffc900233a4000
  RIP: 0010:__put_page+0x56/0x79
  Call Trace:
    devm_memremap_pages_release+0x155/0x23a
    release_nodes+0x21e/0x260
    devres_release_all+0x3c/0x48
    device_release_driver_internal+0x15c/0x207
    device_release_driver+0x12/0x14
    unbind_store+0xba/0xd8
    drv_attr_store+0x27/0x31
    sysfs_kf_write+0x3f/0x46
    kernfs_fop_write+0x10f/0x18b
    __vfs_write+0x3a/0x16d
    vfs_write+0xb2/0x1a1
    SyS_write+0x55/0xb9
    do_syscall_64+0x79/0x1ae
    entry_SYSCALL_64_after_hwframe+0x3d/0x0

Add code to check whether we have a mapping already in the same section
and prevent additional mappings from being created if that is the case.

Link: http://lkml.kernel.org/r/152909478401.50143.312364396244072931.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Martin KaFai Lau 5f300e8004 bpf: btf: Use exact btf value_size match in map_check_btf()
The current map_check_btf() in BPF_MAP_TYPE_ARRAY rejects
'> map->value_size' to ensure map_seq_show_elem() will not
access things beyond an array element.

Yonghong suggested that using '!=' is a more correct
check.  The 8 bytes round_up on value_size is stored
in array->elem_size.  Hence, using '!=' on map->value_size
is a proper check.

This patch also adds new tests to check the btf array
key type and value type.  Two of these new tests verify
the btf's value_size (the change in this patch).

It also fixes two existing tests that wrongly encoded
a btf's type size (pprint_test) and the value_type_id (in one
of the raw_tests[]).  However, that do not affect these two
BTF verification tests before or after this test changes.
These two tests mainly failed at array creation time after
this patch.

Fixes: a26ca7c982 ("bpf: btf: Add pretty print support to the basic arraymap")
Suggested-by: Yonghong Song <yhs@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 03:45:49 +02:00
Masami Hiramatsu 1fee4f7752 doc: tracing: Fix a typo of trace_stat
The name of the directory for per-cpu function statistics
is trace_stat, not trace_stats.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-26 15:48:10 -06:00
Masami Hiramatsu 72809cbf67 tracing: Remove orphaned function ftrace_nr_registered_ops()
Remove ftrace_nr_registered_ops() because it is no longer used.

ftrace_nr_registered_ops() has been introduced by commit ea701f11da
("ftrace: Add selftest to test function trace recursion protection"), but
its caller has been removed by commit 05cbbf643b ("tracing: Fix selftest
function recursion accounting"). So it is not called anymore.

Link: http://lkml.kernel.org/r/153260907227.12474.5234899025934963683.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 10:58:43 -04:00
Masami Hiramatsu 7b144b6c79 tracing: Remove orphaned function using_ftrace_ops_list_func().
Remove using_ftrace_ops_list_func() since it is no longer used.

Using ftrace_ops_list_func() has been introduced by commit 7eea4fce02
("tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_func")
as a helper function, but its caller has been removed by commit 72ac426a5b
("tracing: Clean up stack tracing and fix fentry updates").  So it is not
called anymore.

Link: http://lkml.kernel.org/r/153260904427.12474.9952096317439329851.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 10:53:05 -04:00
Steven Rostedt (VMware) f6b7425cfb tracing: Make unregister_trigger() static
Nothing uses unregister_trigger() outside of trace_events_trigger.c file,
thus it should be static. Not sure why this was ever converted, because
its counter part, register_trigger(), was always static.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 10:50:18 -04:00
Joel Fernandes (Google) f96e8577da lib: Add module for testing preemptoff/irqsoff latency tracers
Here we introduce a test module for introducing a long preempt or irq
disable delay in the kernel which the preemptoff or irqsoff tracers can
detect. This module is to be used only for test purposes and is default
disabled.

Following is the expected output (only briefly shown) that can be parsed
to verify that the tracers are working correctly. We will use this from
the kselftests in future patches.

For the preemptoff tracer:

echo preemptoff > /d/tracing/current_tracer
sleep 1
insmod ./preemptirq_delay_test.ko test_mode=preempt delay=500000
sleep 1
bash-4.3# cat /d/tracing/trace
preempt -1066    2...2    0us@: preemptirq_delay_run <-preemptirq_delay_run
preempt -1066    2...2 500002us : preemptirq_delay_run <-preemptirq_delay_run
preempt -1066    2...2 500004us : tracer_preempt_on <-preemptirq_delay_run
preempt -1066    2...2 500012us : <stack trace>
 => kthread
 => ret_from_fork

For the irqsoff tracer:

echo irqsoff > /d/tracing/current_tracer
sleep 1
insmod ./preemptirq_delay_test.ko test_mode=irq delay=500000
sleep 1
bash-4.3# cat /d/tracing/trace
irq dis -1069    1d..1    0us@: preemptirq_delay_run
irq dis -1069    1d..1 500001us : preemptirq_delay_run
irq dis -1069    1d..1 500002us : tracer_hardirqs_on <-preemptirq_delay_run
irq dis -1069    1d..1 500005us : <stack trace>
 => ret_from_fork

Link: http://lkml.kernel.org/r/20180712213611.GA8743@joelaf.mtv.corp.google.com

Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Julia Cartwright <julia@ni.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Glexiner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[ Erick is a co-developer of this commit ]
Signed-off-by: Erick Reyes <erickreyes@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 10:50:17 -04:00
Joel Fernandes (Google) 2b27ece6c5 tracing/irqsoff: Split reset into separate functions
Split reset functions into seperate functions in preparation
of future patches that need to do tracer specific reset.

Link: http://lkml.kernel.org/r/20180628182149.226164-4-joel@joelfernandes.org

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 10:50:17 -04:00
Snild Dolkow 3e536e222f kthread, tracing: Don't expose half-written comm when creating kthreads
There is a window for racing when printing directly to task->comm,
allowing other threads to see a non-terminated string. The vsnprintf
function fills the buffer, counts the truncated chars, then finally
writes the \0 at the end.

	creator                     other
	vsnprintf:
	  fill (not terminated)
	  count the rest            trace_sched_waking(p):
	  ...                         memcpy(comm, p->comm, TASK_COMM_LEN)
	  write \0

The consequences depend on how 'other' uses the string. In our case,
it was copied into the tracing system's saved cmdlines, a buffer of
adjacent TASK_COMM_LEN-byte buffers (note the 'n' where 0 should be):

	crash-arm64> x/1024s savedcmd->saved_cmdlines | grep 'evenk'
	0xffffffd5b3818640:     "irq/497-pwr_evenkworker/u16:12"

...and a strcpy out of there would cause stack corruption:

	[224761.522292] Kernel panic - not syncing: stack-protector:
	    Kernel stack is corrupted in: ffffff9bf9783c78

	crash-arm64> kbt | grep 'comm\|trace_print_context'
	#6  0xffffff9bf9783c78 in trace_print_context+0x18c(+396)
	      comm (char [16]) =  "irq/497-pwr_even"

	crash-arm64> rd 0xffffffd4d0e17d14 8
	ffffffd4d0e17d14:  2f71726900000000 5f7277702d373934   ....irq/497-pwr_
	ffffffd4d0e17d24:  726f776b6e657665 3a3631752f72656b   evenkworker/u16:
	ffffffd4d0e17d34:  f9780248ff003231 cede60e0ffffff9b   12..H.x......`..
	ffffffd4d0e17d44:  cede60c8ffffffd4 00000fffffffffd4   .....`..........

The workaround in e09e28671 (use strlcpy in __trace_find_cmdline) was
likely needed because of this same bug.

Solved by vsnprintf:ing to a local buffer, then using set_task_comm().
This way, there won't be a window where comm is not terminated.

Link: http://lkml.kernel.org/r/20180726071539.188015-1-snild@sony.com

Cc: stable@vger.kernel.org
Fixes: bc0c38d139 ("ftrace: latency tracer infrastructure")
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Snild Dolkow <snild@sony.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-26 09:59:33 -04:00
Waiman Long 6f4ceee930 cpu/hotplug: Add a cpus_read_trylock() function
There are use cases where it can be useful to have a cpus_read_trylock()
function to work around circular lock dependency problem involving
the cpu_hotplug_lock.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-07-26 10:37:36 +02:00
Steven Rostedt (VMware) 2519c1bbe3 tracing: Quiet gcc warning about maybe unused link variable
Commit 57ea2a34ad ("tracing/kprobes: Fix trace_probe flags on
enable_trace_kprobe() failure") added an if statement that depends on another
if statement that gcc doesn't see will initialize the "link" variable and
gives the warning:

 "warning: 'link' may be used uninitialized in this function"

It is really a false positive, but to quiet the warning, and also to make
sure that it never actually is used uninitialized, initialize the "link"
variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler
thinks it could be used uninitialized.

Cc: stable@vger.kernel.org
Fixes: 57ea2a34ad ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 22:33:50 -04:00
Steven Rostedt (VMware) 15cc78644d tracing: Fix possible double free in event_enable_trigger_func()
There was a case that triggered a double free in event_trigger_callback()
due to the called reg() function freeing the trigger_data and then it
getting freed again by the error return by the caller. The solution there
was to up the trigger_data ref count.

Code inspection found that event_enable_trigger_func() has the same issue,
but is not as easy to trigger (requires harder to trigger failures). It
needs to be solved slightly different as it needs more to clean up when the
reg() function fails.

Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 7862ad1846 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands")
Reivewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 21:25:16 -04:00
Artem Savkov 57ea2a34ad tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
it returns an error, but does not unset the tp flags it set previously.
This results in a probe being considered enabled and failures like being
unable to remove the probe through kprobe_events file since probes_open()
expects every probe to be disabled.

Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com
Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 41a7dd420c ("tracing/kprobes: Support ftrace_event_file base multibuffer")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 11:41:08 -04:00
Masami Hiramatsu 73c8d89455 ring_buffer: tracing: Inherit the tracing setting to next ring buffer
Maintain the tracing on/off setting of the ring_buffer when switching
to the trace buffer snapshot.

Taking a snapshot is done by swapping the backup ring buffer
(max_tr_buffer). But since the tracing on/off setting is defined
by the ring buffer, when swapping it, the tracing on/off setting
can also be changed. This causes a strange result like below:

  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 0 > tracing_on
  /sys/kernel/debug/tracing # cat tracing_on
  0
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  0

We don't touch tracing_on, but snapshot changes tracing_on
setting each time. This is an anomaly, because user doesn't know
that each "ring_buffer" stores its own tracing-enable state and
the snapshot is done by swapping ring buffers.

Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp>
Cc: stable@vger.kernel.org
Fixes: debdd57f51 ("tracing: Make a snapshot feature available from userspace")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Updated commit log and comment in the code ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 10:29:41 -04:00
Steven Rostedt (VMware) 1863c38725 tracing: Fix double free of event_trigger_data
Running the following:

 # cd /sys/kernel/debug/tracing
 # echo 500000 > buffer_size_kb
[ Or some other number that takes up most of memory ]
 # echo snapshot > events/sched/sched_switch/trigger

Triggers the following bug:

 ------------[ cut here ]------------
 kernel BUG at mm/slub.c:296!
 invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:kfree+0x16c/0x180
 Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f
 RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246
 RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80
 RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500
 RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be
 R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be
 R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00
 FS:  00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0
 Call Trace:
  event_trigger_callback+0xee/0x1d0
  event_trigger_write+0xfc/0x1a0
  __vfs_write+0x33/0x190
  ? handle_mm_fault+0x115/0x230
  ? _cond_resched+0x16/0x40
  vfs_write+0xb0/0x190
  ksys_write+0x52/0xc0
  do_syscall_64+0x5a/0x160
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7f363e16ab50
 Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24
 RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50
 RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001
 RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009
 R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0
 Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper
86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e
 ---[ end trace d301afa879ddfa25 ]---

The cause is because the register_snapshot_trigger() call failed to
allocate the snapshot buffer, and then called unregister_trigger()
which freed the data that was passed to it. Then on return to the
function that called register_snapshot_trigger(), as it sees it
failed to register, it frees the trigger_data again and causes
a double free.

By calling event_trigger_init() on the trigger_data (which only ups
the reference counter for it), and then event_trigger_free() afterward,
the trigger_data would not get freed by the registering trigger function
as it would only up and lower the ref count for it. If the register
trigger function fails, then the event_trigger_free() called after it
will free the trigger data normally.

Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home

Cc: stable@vger.kerne.org
Fixes: 93e31ffbf4 ("tracing: Add 'snapshot' event trigger command")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-25 10:29:24 -04:00
Kees Cook 7d63fb3af8 swiotlb: clean up reporting
This removes needless use of '%p', and refactors the printk calls to
use pr_*() helpers instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-07-25 13:33:05 +02:00
Ingo Molnar 93081caaae Merge branch 'perf/urgent' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:47:02 +02:00
Mathieu Poirier 7f635ff187 perf/core: Fix crash when using HW tracing kernel filters
In function perf_event_parse_addr_filter(), the path::dentry of each struct
perf_addr_filter is left unassigned (as it should be) when the pattern
being parsed is related to kernel space.  But in function
perf_addr_filter_match() the same dentries are given to d_inode() where
the value is not expected to be NULL, resulting in the following splat:

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
  pc : perf_event_mmap+0x2fc/0x5a0
  lr : perf_event_mmap+0x2c8/0x5a0
  Process uname (pid: 2860, stack limit = 0x000000001cbcca37)
  Call trace:
   perf_event_mmap+0x2fc/0x5a0
   mmap_region+0x124/0x570
   do_mmap+0x344/0x4f8
   vm_mmap_pgoff+0xe4/0x110
   vm_mmap+0x2c/0x40
   elf_map+0x60/0x108
   load_elf_binary+0x450/0x12c4
   search_binary_handler+0x90/0x290
   __do_execve_file.isra.13+0x6e4/0x858
   sys_execve+0x3c/0x50
   el0_svc_naked+0x30/0x34

This patch is fixing the problem by introducing a new check in function
perf_addr_filter_match() to see if the filter's dentry is NULL.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.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>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: miklos@szeredi.hu
Cc: namhyung@kernel.org
Cc: songliubraving@fb.com
Fixes: 9511bce9fe ("perf/core: Fix bad use of igrab()")
Link: http://lkml.kernel.org/r/1531782831-1186-1-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:46:22 +02:00
Peter Zijlstra 6cbc304f2f perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)
Vince reported the perf_fuzzer giving various unwinder warnings and
Josh reported:

> Deja vu.  Most of these are related to perf PEBS, similar to the
> following issue:
>
>   b8000586c9 ("perf/x86/intel: Cure bogus unwind from PEBS entries")
>
> This is basically the ORC version of that.  setup_pebs_sample_data() is
> assembling a franken-pt_regs which ORC isn't happy about.  RIP is
> inconsistent with some of the other registers (like RSP and RBP).

And where the previous unwinder only needed BP,SP ORC also requires
IP. But we cannot spoof IP because then the sample will get displaced,
entirely negating the point of PEBS.

So cure the whole thing differently by doing the unwind early; this
does however require a means to communicate we did the unwind early.
We (ab)use an unused sample_type bit for this, which we set on events
that fill out the data->callchain before the normal
perf_prepare_sample().

Debugged-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.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>
2018-07-25 11:46:21 +02:00
Srikar Dronamraju b6a60cf36d sched/numa: Move task_numa_placement() closer to numa_migrate_preferred()
numa_migrate_preferred() is called periodically or when task preferred
node changes. Preferred node evaluations happen once per scan sequence.

If the scan completion happens just after the periodic NUMA migration,
then we try to migrate to the preferred node and the preferred node might
change, needing another node migration.

Avoid this by checking for scan sequence completion only when checking
for periodic migration.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25862.6     26158.1     1.14258
1     74357       72725       -2.19482

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
8     117019      113992      -2.58
1     179095      174947      -2.31

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      449.46      770.77      615.22      101.70
numa01.sh       Sys:      132.72      208.17      170.46       24.96
numa01.sh      User:    39185.26    60290.89    50066.76     6807.84
numa02.sh      Real:       60.85       61.79       61.28        0.37
numa02.sh       Sys:       15.34       24.71       21.08        3.61
numa02.sh      User:     5204.41     5249.85     5231.21       17.60
numa03.sh      Real:      785.50      916.97      840.77       44.98
numa03.sh       Sys:      108.08      133.60      119.43        8.82
numa03.sh      User:    61422.86    70919.75    64720.87     3310.61
numa04.sh      Real:      429.57      587.37      480.80       57.40
numa04.sh       Sys:      240.61      321.97      290.84       33.58
numa04.sh      User:    34597.65    40498.99    37079.48     2060.72
numa05.sh      Real:      392.09      431.25      414.65       13.82
numa05.sh       Sys:      229.41      372.48      297.54       53.14
numa05.sh      User:    33390.86    34697.49    34222.43      556.42

Testcase       Time:         Min         Max         Avg      StdDev 	%Change
numa01.sh      Real:      424.63      566.18      498.12       59.26 	 23.50%
numa01.sh       Sys:      160.19      256.53      208.98       37.02 	 -18.4%
numa01.sh      User:    37320.00    46225.58    42001.57     3482.45 	 19.20%
numa02.sh      Real:       60.17       62.47       60.91        0.85 	 0.607%
numa02.sh       Sys:       15.30       22.82       17.04        2.90 	 23.70%
numa02.sh      User:     5202.13     5255.51     5219.08       20.14 	 0.232%
numa03.sh      Real:      823.91      844.89      833.86        8.46 	 0.828%
numa03.sh       Sys:      130.69      148.29      140.47        6.21 	 -14.9%
numa03.sh      User:    62519.15    64262.20    63613.38      620.05 	 1.740%
numa04.sh      Real:      515.30      603.74      548.56       30.93 	 -12.3%
numa04.sh       Sys:      459.73      525.48      489.18       21.63 	 -40.5%
numa04.sh      User:    40561.96    44919.18    42047.87     1526.85 	 -11.8%
numa05.sh      Real:      396.58      454.37      421.13       19.71 	 -1.53%
numa05.sh       Sys:      208.72      422.02      348.90       73.60 	 -14.7%
numa05.sh      User:    33124.08    36109.35    34846.47     1089.74 	 -1.79%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-20-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:08 +02:00
Srikar Dronamraju f35678b6a1 sched/numa: Use group_weights to identify if migration degrades locality
On NUMA_BACKPLANE and NUMA_GLUELESS_MESH systems, tasks/memory should be
consolidated to the closest group of nodes. In such a case, relying on
group_fault metric may not always help to consolidate. There can always
be a case where a node closer to the preferred node may have lesser
faults than a node further away from the preferred node. In such a case,
moving to node with more faults might avoid numa consolidation.

Using group_weight would help to consolidate task/memory around the
preferred_node.

While here, to be on the conservative side, don't override migrate thread
degrades locality logic for CPU_NEWLY_IDLE load balancing.

Note: Similar problems exist with should_numa_migrate_memory and will be
dealt separately.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25645.4     25960       1.22
1     72142       73550       1.95

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
8     110199      120071      8.958
1     176303      176249      -0.03

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      490.04      774.86      596.26       96.46
numa01.sh       Sys:      151.52      242.88      184.82       31.71
numa01.sh      User:    41418.41    60844.59    48776.09     6564.27
numa02.sh      Real:       60.14       62.94       60.98        1.00
numa02.sh       Sys:       16.11       30.77       21.20        5.28
numa02.sh      User:     5184.33     5311.09     5228.50       44.24
numa03.sh      Real:      790.95      856.35      826.41       24.11
numa03.sh       Sys:      114.93      118.85      117.05        1.63
numa03.sh      User:    60990.99    64959.28    63470.43     1415.44
numa04.sh      Real:      434.37      597.92      504.87       59.70
numa04.sh       Sys:      237.63      397.40      289.74       55.98
numa04.sh      User:    34854.87    41121.83    38572.52     2615.84
numa05.sh      Real:      386.77      448.90      417.22       22.79
numa05.sh       Sys:      149.23      379.95      303.04       79.55
numa05.sh      User:    32951.76    35959.58    34562.18     1034.05

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      493.19      672.88      597.51       59.38 	 -0.20%
numa01.sh       Sys:      150.09      245.48      207.76       34.26 	 -11.0%
numa01.sh      User:    41928.51    53779.17    48747.06     3901.39 	 0.059%
numa02.sh      Real:       60.63       62.87       61.22        0.83 	 -0.39%
numa02.sh       Sys:       16.64       27.97       20.25        4.06 	 4.691%
numa02.sh      User:     5222.92     5309.60     5254.03       29.98 	 -0.48%
numa03.sh      Real:      821.52      902.15      863.60       32.41 	 -4.30%
numa03.sh       Sys:      112.04      130.66      118.35        7.08 	 -1.09%
numa03.sh      User:    62245.16    69165.14    66443.04     2450.32 	 -4.47%
numa04.sh      Real:      414.53      519.57      476.25       37.00 	 6.009%
numa04.sh       Sys:      181.84      335.67      280.41       54.07 	 3.327%
numa04.sh      User:    33924.50    39115.39    37343.78     1934.26 	 3.290%
numa05.sh      Real:      408.30      441.45      417.90       12.05 	 -0.16%
numa05.sh       Sys:      233.41      381.60      295.58       57.37 	 2.523%
numa05.sh      User:    33301.31    35972.50    34335.19      938.94 	 0.661%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-16-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:08 +02:00
Srikar Dronamraju 30619c89b1 sched/numa: Update the scan period without holding the numa_group lock
The metrics for updating scan periods are local or task specific.
Currently this update happens under the numa_group lock, which seems
unnecessary. Hence move this update outside the lock.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25355.9     25645.4     1.141
1     72812       72142       -0.92

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
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/1529514181-9842-15-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:08 +02:00
Srikar Dronamraju 2d4056fafa sched/numa: Remove numa_has_capacity()
task_numa_find_cpu() helps to find the CPU to swap/move the task to.
It's guarded by numa_has_capacity(). However node not having capacity
shouldn't deter a task swapping if it helps NUMA placement.

Further load_too_imbalanced(), which evaluates possibilities of move/swap,
provides similar checks as numa_has_capacity.

Hence remove numa_has_capacity() to enhance possibilities of task
swapping even if load is imbalanced.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25657.9     25804.1     0.569
1     74435       73413       -1.37

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-13-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:08 +02:00
Srikar Dronamraju 0ad4e3dfe6 sched/numa: Modify migrate_swap() to accept additional parameters
There are checks in migrate_swap_stop() that check if the task/CPU
combination is as per migrate_swap_arg before migrating.

However atleast one of the two tasks to be swapped by migrate_swap() could
have migrated to a completely different CPU before updating the
migrate_swap_arg. The new CPU where the task is currently running could
be a different node too. If the task has migrated, numa balancer might
end up placing a task in a wrong node.  Instead of achieving node
consolidation, it may end up spreading the load across nodes.

To avoid that pass the CPUs as additional parameters.

While here, place migrate_swap under CONFIG_NUMA_BALANCING.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25377.3     25226.6     -0.59
1     72287       73326       1.437

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
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/1529514181-9842-10-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:07 +02:00
Srikar Dronamraju 10864a9e22 sched/numa: Remove unused task_capacity from 'struct numa_stats'
The task_capacity field in 'struct numa_stats' is redundant.
Also move nr_running for better packing within the struct.

No functional changes.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25308.6     25377.3     0.271
1     72964       72287       -0.92

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Rik van Riel <riel@surriel.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/1529514181-9842-9-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:07 +02:00
Srikar Dronamraju 0ee7e74dc0 sched/numa: Skip nodes that are at 'hoplimit'
When comparing two nodes at a distance of 'hoplimit', we should consider
nodes only up to 'hoplimit'. Currently we also consider nodes at 'oplimit'
distance too. Hence two nodes at a distance of 'hoplimit' will have same
groupweight. Fix this by skipping nodes at hoplimit.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25375.3     25308.6     -0.26
1     72617       72964       0.477

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
8     113372      108750      -4.07684
1     177403      183115      3.21979

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      478.45      565.90      515.11       30.87
numa01.sh       Sys:      207.79      271.04      232.94       21.33
numa01.sh      User:    39763.93    47303.12    43210.73     2644.86
numa02.sh      Real:       60.00       61.46       60.78        0.49
numa02.sh       Sys:       15.71       25.31       20.69        3.42
numa02.sh      User:     5175.92     5265.86     5235.97       32.82
numa03.sh      Real:      776.42      834.85      806.01       23.22
numa03.sh       Sys:      114.43      128.75      121.65        5.49
numa03.sh      User:    60773.93    64855.25    62616.91     1576.39
numa04.sh      Real:      456.93      511.95      482.91       20.88
numa04.sh       Sys:      178.09      460.89      356.86       94.58
numa04.sh      User:    36312.09    42553.24    39623.21     2247.96
numa05.sh      Real:      393.98      493.48      436.61       35.59
numa05.sh       Sys:      164.49      329.15      265.87       61.78
numa05.sh      User:    33182.65    36654.53    35074.51     1187.71

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      414.64      819.20      556.08      147.70 	 -7.36%
numa01.sh       Sys:       77.52      205.04      139.40       52.05 	 67.10%
numa01.sh      User:    37043.24    61757.88    45517.48     9290.38 	 -5.06%
numa02.sh      Real:       60.80       63.32       61.63        0.88 	 -1.37%
numa02.sh       Sys:       17.35       39.37       25.71        7.33 	 -19.5%
numa02.sh      User:     5213.79     5374.73     5268.90       55.09 	 -0.62%
numa03.sh      Real:      780.09      948.64      831.43       63.02 	 -3.05%
numa03.sh       Sys:      104.96      136.92      116.31       11.34 	 4.591%
numa03.sh      User:    60465.42    73339.78    64368.03     4700.14 	 -2.72%
numa04.sh      Real:      412.60      681.92      521.29       96.64 	 -7.36%
numa04.sh       Sys:      210.32      314.10      251.77       37.71 	 41.74%
numa04.sh      User:    34026.38    45581.20    38534.49     4198.53 	 2.825%
numa05.sh      Real:      394.79      439.63      411.35       16.87 	 6.140%
numa05.sh       Sys:      238.32      330.09      292.31       38.32 	 -9.04%
numa05.sh      User:    33456.45    34876.07    34138.62      609.45 	 2.741%

While there is a regression with this change, this change is needed from a
correctness perspective. Also it helps consolidation as seen from perf bench
output.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
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/1529514181-9842-8-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:07 +02:00
Srikar Dronamraju 67d9f6c256 sched/debug: Reverse the order of printing faults
Fix the order in which the private and shared numa faults are getting
printed.

No functional changes.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25215.7     25375.3     0.63
1     72107       72617       0.70

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
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/1529514181-9842-7-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:07 +02:00
Srikar Dronamraju f03bb6760b sched/numa: Use task faults only if numa_group is not yet set up
When numa_group faults are available, task_numa_placement only uses
numa_group faults to evaluate preferred node. However it still accounts
task faults and even evaluates the preferred node just based on task
faults just to discard it in favour of preferred node chosen on the
basis of numa_group.

Instead use task faults only if numa_group is not set.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25549.6     25215.7     -1.30
1     73190       72107       -1.47

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
8     113437      113372      -0.05
1     196130      177403      -9.54

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      506.35      794.46      599.06      104.26
numa01.sh       Sys:      150.37      223.56      195.99       24.94
numa01.sh      User:    43450.69    61752.04    49281.50     6635.33
numa02.sh      Real:       60.33       62.40       61.31        0.90
numa02.sh       Sys:       18.12       31.66       24.28        5.89
numa02.sh      User:     5203.91     5325.32     5260.29       49.98
numa03.sh      Real:      696.47      853.62      745.80       57.28
numa03.sh       Sys:       85.68      123.71       97.89       13.48
numa03.sh      User:    55978.45    66418.63    59254.94     3737.97
numa04.sh      Real:      444.05      514.83      497.06       26.85
numa04.sh       Sys:      230.39      375.79      316.23       48.58
numa04.sh      User:    35403.12    41004.10    39720.80     2163.08
numa05.sh      Real:      423.09      460.41      439.57       13.92
numa05.sh       Sys:      287.38      480.15      369.37       68.52
numa05.sh      User:    34732.12    38016.80    36255.85     1070.51

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      478.45      565.90      515.11       30.87 	 16.29%
numa01.sh       Sys:      207.79      271.04      232.94       21.33 	 -15.8%
numa01.sh      User:    39763.93    47303.12    43210.73     2644.86 	 14.04%
numa02.sh      Real:       60.00       61.46       60.78        0.49 	 0.871%
numa02.sh       Sys:       15.71       25.31       20.69        3.42 	 17.35%
numa02.sh      User:     5175.92     5265.86     5235.97       32.82 	 0.464%
numa03.sh      Real:      776.42      834.85      806.01       23.22 	 -7.47%
numa03.sh       Sys:      114.43      128.75      121.65        5.49 	 -19.5%
numa03.sh      User:    60773.93    64855.25    62616.91     1576.39 	 -5.36%
numa04.sh      Real:      456.93      511.95      482.91       20.88 	 2.930%
numa04.sh       Sys:      178.09      460.89      356.86       94.58 	 -11.3%
numa04.sh      User:    36312.09    42553.24    39623.21     2247.96 	 0.246%
numa05.sh      Real:      393.98      493.48      436.61       35.59 	 0.677%
numa05.sh       Sys:      164.49      329.15      265.87       61.78 	 38.92%
numa05.sh      User:    33182.65    36654.53    35074.51     1187.71 	 3.368%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-6-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:06 +02:00
Srikar Dronamraju 8cd45eee43 sched/numa: Set preferred_node based on best_cpu
Currently preferred node is set to dst_nid which is the last node in the
iteration whose group weight or task weight is greater than the current
node. However it doesn't guarantee that dst_nid has the numa capacity
to move. It also doesn't guarantee that dst_nid has the best_cpu which
is the CPU/node ideal for node migration.

Lets consider faults on a 4 node system with group weight numbers
in different nodes being in 0 < 1 < 2 < 3 proportion. Consider the task
is running on 3 and 0 is its preferred node but its capacity is full.
Consider nodes 1, 2 and 3 have capacity. Then the task should be
migrated to node 1. Currently the task gets moved to node 2. env.dst_nid
points to the last node whose faults were greater than current node.

Modify to set the preferred node based of best_cpu. Earlier setting
preferred node was skipped if nr_active_nodes is 1. This could result in
the task being moved out of the preferred node to a random node during
regular load balancing.

Also while modifying task_numa_migrate(), use sched_setnuma to set
preferred node. This ensures out numa accounting is correct.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25122.9     25549.6     1.698
1     73850       73190       -0.89

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
8     105930      113437      7.08676
1     178624      196130      9.80047

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      435.78      653.81      534.58       83.20
numa01.sh       Sys:      121.93      187.18      145.90       23.47
numa01.sh      User:    37082.81    51402.80    43647.60     5409.75
numa02.sh      Real:       60.64       61.63       61.19        0.40
numa02.sh       Sys:       14.72       25.68       19.06        4.03
numa02.sh      User:     5210.95     5266.69     5233.30       20.82
numa03.sh      Real:      746.51      808.24      780.36       23.88
numa03.sh       Sys:       97.26      108.48      105.07        4.28
numa03.sh      User:    58956.30    61397.05    60162.95     1050.82
numa04.sh      Real:      465.97      519.27      484.81       19.62
numa04.sh       Sys:      304.43      359.08      334.68       20.64
numa04.sh      User:    37544.16    41186.15    39262.44     1314.91
numa05.sh      Real:      411.57      457.20      433.29       16.58
numa05.sh       Sys:      230.05      435.48      339.95       67.58
numa05.sh      User:    33325.54    36896.31    35637.84     1222.64

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      506.35      794.46      599.06      104.26 	 -10.76%
numa01.sh       Sys:      150.37      223.56      195.99       24.94 	 -25.55%
numa01.sh      User:    43450.69    61752.04    49281.50     6635.33 	 -11.43%
numa02.sh      Real:       60.33       62.40       61.31        0.90 	 -0.195%
numa02.sh       Sys:       18.12       31.66       24.28        5.89 	 -21.49%
numa02.sh      User:     5203.91     5325.32     5260.29       49.98 	 -0.513%
numa03.sh      Real:      696.47      853.62      745.80       57.28 	 4.6339%
numa03.sh       Sys:       85.68      123.71       97.89       13.48 	 7.3347%
numa03.sh      User:    55978.45    66418.63    59254.94     3737.97 	 1.5323%
numa04.sh      Real:      444.05      514.83      497.06       26.85 	 -2.464%
numa04.sh       Sys:      230.39      375.79      316.23       48.58 	 5.8343%
numa04.sh      User:    35403.12    41004.10    39720.80     2163.08 	 -1.153%
numa05.sh      Real:      423.09      460.41      439.57       13.92 	 -1.428%
numa05.sh       Sys:      287.38      480.15      369.37       68.52 	 -7.964%
numa05.sh      User:    34732.12    38016.80    36255.85     1070.51 	 -1.704%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-5-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:06 +02:00
Srikar Dronamraju 5f95ba7a43 sched/numa: Simplify load_too_imbalanced()
Currently load_too_imbalance() cares about the slope of imbalance.
It doesn't care of the direction of the imbalance.

However this may not work if nodes that are being compared have
dissimilar capacities. Few nodes might have more cores than other nodes
in the system. Also unlike traditional load balance at a NUMA sched
domain, multiple requests to migrate from the same source node to same
destination node may run in parallel. This can cause huge load
imbalance. This is specially true on a larger machines with either large
cores per node or more number of nodes in the system. Hence allow
move/swap only if the imbalance is going to reduce.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25058.2     25122.9     0.25
1     72950       73850       1.23

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      516.14      892.41      739.84      151.32
numa01.sh       Sys:      153.16      192.99      177.70       14.58
numa01.sh      User:    39821.04    69528.92    57193.87    10989.48
numa02.sh      Real:       60.91       62.35       61.58        0.63
numa02.sh       Sys:       16.47       26.16       21.20        3.85
numa02.sh      User:     5227.58     5309.61     5265.17       31.04
numa03.sh      Real:      739.07      917.73      795.75       64.45
numa03.sh       Sys:       94.46      136.08      109.48       14.58
numa03.sh      User:    57478.56    72014.09    61764.48     5343.69
numa04.sh      Real:      442.61      715.43      530.31       96.12
numa04.sh       Sys:      224.90      348.63      285.61       48.83
numa04.sh      User:    35836.84    47522.47    40235.41     3985.26
numa05.sh      Real:      386.13      489.17      434.94       43.59
numa05.sh       Sys:      144.29      438.56      278.80      105.78
numa05.sh      User:    33255.86    36890.82    34879.31     1641.98

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      435.78      653.81      534.58       83.20 	 38.39%
numa01.sh       Sys:      121.93      187.18      145.90       23.47 	 21.79%
numa01.sh      User:    37082.81    51402.80    43647.60     5409.75 	 31.03%
numa02.sh      Real:       60.64       61.63       61.19        0.40 	 0.637%
numa02.sh       Sys:       14.72       25.68       19.06        4.03 	 11.22%
numa02.sh      User:     5210.95     5266.69     5233.30       20.82 	 0.608%
numa03.sh      Real:      746.51      808.24      780.36       23.88 	 1.972%
numa03.sh       Sys:       97.26      108.48      105.07        4.28 	 4.197%
numa03.sh      User:    58956.30    61397.05    60162.95     1050.82 	 2.661%
numa04.sh      Real:      465.97      519.27      484.81       19.62 	 9.385%
numa04.sh       Sys:      304.43      359.08      334.68       20.64 	 -14.6%
numa04.sh      User:    37544.16    41186.15    39262.44     1314.91 	 2.478%
numa05.sh      Real:      411.57      457.20      433.29       16.58 	 0.380%
numa05.sh       Sys:      230.05      435.48      339.95       67.58 	 -17.9%
numa05.sh      User:    33325.54    36896.31    35637.84     1222.64 	 -2.12%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
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/1529514181-9842-4-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:06 +02:00
Srikar Dronamraju 305c1fac32 sched/numa: Evaluate move once per node
task_numa_compare() helps choose the best CPU to move or swap the
selected task. To achieve this task_numa_compare() is called for every
CPU in the node. Currently it evaluates if the task can be moved/swapped
for each of the CPUs. However the move evaluation is mostly independent
of the CPU. Evaluating the move logic once per node, provides scope for
simplifying task_numa_compare().

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25705.2     25058.2     -2.51
1     74433       72950       -1.99

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
8     96589.6     105930      9.670
1     181830      178624      -1.76

(numbers from v1 based on v4.17-rc5)
Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      440.65      941.32      758.98      189.17
numa01.sh       Sys:      183.48      320.07      258.42       50.09
numa01.sh      User:    37384.65    71818.14    60302.51    13798.96
numa02.sh      Real:       61.24       65.35       62.49        1.49
numa02.sh       Sys:       16.83       24.18       21.40        2.60
numa02.sh      User:     5219.59     5356.34     5264.03       49.07
numa03.sh      Real:      822.04      912.40      873.55       37.35
numa03.sh       Sys:      118.80      140.94      132.90        7.60
numa03.sh      User:    62485.19    70025.01    67208.33     2967.10
numa04.sh      Real:      690.66      872.12      778.49       65.44
numa04.sh       Sys:      459.26      563.03      494.03       42.39
numa04.sh      User:    51116.44    70527.20    58849.44     8461.28
numa05.sh      Real:      418.37      562.28      525.77       54.27
numa05.sh       Sys:      299.45      481.00      392.49       64.27
numa05.sh      User:    34115.09    41324.02    39105.30     2627.68

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      516.14      892.41      739.84      151.32 	 2.587%
numa01.sh       Sys:      153.16      192.99      177.70       14.58 	 45.42%
numa01.sh      User:    39821.04    69528.92    57193.87    10989.48 	 5.435%
numa02.sh      Real:       60.91       62.35       61.58        0.63 	 1.477%
numa02.sh       Sys:       16.47       26.16       21.20        3.85 	 0.943%
numa02.sh      User:     5227.58     5309.61     5265.17       31.04 	 -0.02%
numa03.sh      Real:      739.07      917.73      795.75       64.45 	 9.776%
numa03.sh       Sys:       94.46      136.08      109.48       14.58 	 21.39%
numa03.sh      User:    57478.56    72014.09    61764.48     5343.69 	 8.813%
numa04.sh      Real:      442.61      715.43      530.31       96.12 	 46.79%
numa04.sh       Sys:      224.90      348.63      285.61       48.83 	 72.97%
numa04.sh      User:    35836.84    47522.47    40235.41     3985.26 	 46.26%
numa05.sh      Real:      386.13      489.17      434.94       43.59 	 20.88%
numa05.sh       Sys:      144.29      438.56      278.80      105.78 	 40.77%
numa05.sh      User:    33255.86    36890.82    34879.31     1641.98 	 12.11%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-3-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:06 +02:00
Yun Wang 3d6c50c27b sched/debug: Show the sum wait time of a task group
Although we can rely on cpuacct to present the CPU usage of task
groups, it is hard to tell how intense the competition is between
these groups on CPU resources.

Monitoring the wait time or sched_debug of each process could be
very expensive, and there is no good way to accurately represent the
conflict with these info, we need the wait time on group dimension.

Thus we introduce group's wait_sum to represent the resource conflict
between task groups, which is simply the sum of the wait time of
the group's cfs_rq.

The 'cpu.stat' is modified to show the statistic, like:

   nr_periods 0
   nr_throttled 0
   throttled_time 0
   wait_sum 2035098795584

Now we can monitor the changes of wait_sum to tell how much a
a task group is suffering in the fight of CPU resources.

For example:

   (wait_sum - last_wait_sum) * 100 / (nr_cpu * period_ns) == X%

means the task group paid X percentage of period on waiting
for the CPU.

Signed-off-by: Michael Wang <yun.wang@linux.alibaba.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>
Link: http://lkml.kernel.org/r/ff7dae3b-e5f9-7157-1caa-ff02c6b23dc1@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:05 +02:00
Vincent Guittot 2e62c4743a sched/fair: Remove #ifdefs from scale_rt_capacity()
Reuse cpu_util_irq() that has been defined for schedutil and set irq util
to 0 when !CONFIG_IRQ_TIME_ACCOUNTING.

But the compiler is not able to optimize the sequence (at least with
aarch64 GCC 7.2.1):

	free *= (max - irq);
	free /= max;

when irq is fixed to 0

Add a new inline function scale_irq_capacity() that will scale utilization
when irq is accounted. Reuse this funciton in schedutil which applies
similar formula.

Suggested-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/1532001606-6689-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:05 +02:00
Ingo Molnar 4765096f4f Merge branch 'sched/urgent' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:29:58 +02:00
Hailong Liu f3d133ee0a sched/rt: Restore rt_runtime after disabling RT_RUNTIME_SHARE
NO_RT_RUNTIME_SHARE feature is used to prevent a CPU borrow enough
runtime with a spin-rt-task.

However, if RT_RUNTIME_SHARE feature is enabled and rt_rq has borrowd
enough rt_runtime at the beginning, rt_runtime can't be restored to
its initial bandwidth rt_runtime after we disable RT_RUNTIME_SHARE.

E.g. on my PC with 4 cores, procedure to reproduce:
1) Make sure  RT_RUNTIME_SHARE is enabled
 cat /sys/kernel/debug/sched_features
  GENTLE_FAIR_SLEEPERS START_DEBIT NO_NEXT_BUDDY LAST_BUDDY
  CACHE_HOT_BUDDY WAKEUP_PREEMPTION NO_HRTICK NO_DOUBLE_TICK
  LB_BIAS NONTASK_CAPACITY TTWU_QUEUE NO_SIS_AVG_CPU SIS_PROP
  NO_WARN_DOUBLE_CLOCK RT_PUSH_IPI RT_RUNTIME_SHARE NO_LB_MIN
  ATTACH_AGE_LOAD WA_IDLE WA_WEIGHT WA_BIAS
2) Start a spin-rt-task
 ./loop_rr &
3) set affinity to the last cpu
 taskset -p 8 $pid_of_loop_rr
4) Observe that last cpu have borrowed enough runtime.
 cat /proc/sched_debug | grep rt_runtime
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 900.000000
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 1000.000000
5) Disable RT_RUNTIME_SHARE
 echo NO_RT_RUNTIME_SHARE > /sys/kernel/debug/sched_features
6) Observe that rt_runtime can not been restored
 cat /proc/sched_debug | grep rt_runtime
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 900.000000
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 1000.000000

This patch help to restore rt_runtime after we disable
RT_RUNTIME_SHARE.

Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
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: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1531874815-39357-1-git-send-email-liu.hailong6@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:29:08 +02:00
Daniel Bristot de Oliveira 840d719604 sched/deadline: Update rq_clock of later_rq when pushing a task
Daniel Casini got this warn while running a DL task here at RetisLab:

  [  461.137582] ------------[ cut here ]------------
  [  461.137583] rq->clock_update_flags < RQCF_ACT_SKIP
  [  461.137599] WARNING: CPU: 4 PID: 2354 at kernel/sched/sched.h:967 assert_clock_updated.isra.32.part.33+0x17/0x20
      [a ton of modules]
  [  461.137646] CPU: 4 PID: 2354 Comm: label_image Not tainted 4.18.0-rc4+ #3
  [  461.137647] Hardware name: ASUS All Series/Z87-K, BIOS 0801 09/02/2013
  [  461.137649] RIP: 0010:assert_clock_updated.isra.32.part.33+0x17/0x20
  [  461.137649] Code: ff 48 89 83 08 09 00 00 eb c6 66 0f 1f 84 00 00 00 00 00 55 48 c7 c7 98 7a 6c a5 c6 05 bc 0d 54 01 01 48 89 e5 e8 a9 84 fb ff <0f> 0b 5d c3 0f 1f 44 00 00 0f 1f 44 00 00 83 7e 60 01 74 0a 48 3b
  [  461.137673] RSP: 0018:ffffa77e08cafc68 EFLAGS: 00010082
  [  461.137674] RAX: 0000000000000000 RBX: ffff8b3fc1702d80 RCX: 0000000000000006
  [  461.137674] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8b3fded164b0
  [  461.137675] RBP: ffffa77e08cafc68 R08: 0000000000000026 R09: 0000000000000339
  [  461.137676] R10: ffff8b3fd060d410 R11: 0000000000000026 R12: ffffffffa4e14e20
  [  461.137677] R13: ffff8b3fdec22940 R14: ffff8b3fc1702da0 R15: ffff8b3fdec22940
  [  461.137678] FS:  00007efe43ee5700(0000) GS:ffff8b3fded00000(0000) knlGS:0000000000000000
  [  461.137679] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [  461.137680] CR2: 00007efe30000010 CR3: 0000000301744003 CR4: 00000000001606e0
  [  461.137680] Call Trace:
  [  461.137684]  push_dl_task.part.46+0x3bc/0x460
  [  461.137686]  task_woken_dl+0x60/0x80
  [  461.137689]  ttwu_do_wakeup+0x4f/0x150
  [  461.137690]  ttwu_do_activate+0x77/0x80
  [  461.137692]  try_to_wake_up+0x1d6/0x4c0
  [  461.137693]  wake_up_q+0x32/0x70
  [  461.137696]  do_futex+0x7e7/0xb50
  [  461.137698]  __x64_sys_futex+0x8b/0x180
  [  461.137701]  do_syscall_64+0x5a/0x110
  [  461.137703]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [  461.137705] RIP: 0033:0x7efe4918ca26
  [  461.137705] Code: 00 00 00 74 17 49 8b 48 20 44 8b 59 10 41 83 e3 30 41 83 fb 20 74 1e be 85 00 00 00 41 ba 01 00 00 00 41 b9 01 00 00 04 0f 05 <48> 3d 01 f0 ff ff 73 1f 31 c0 c3 be 8c 00 00 00 49 89 c8 4d 31 d2
  [  461.137738] RSP: 002b:00007efe43ee4928 EFLAGS: 00000283 ORIG_RAX: 00000000000000ca
  [  461.137739] RAX: ffffffffffffffda RBX: 0000000005094df0 RCX: 00007efe4918ca26
  [  461.137740] RDX: 0000000000000001 RSI: 0000000000000085 RDI: 0000000005094e24
  [  461.137741] RBP: 00007efe43ee49c0 R08: 0000000005094e20 R09: 0000000004000001
  [  461.137741] R10: 0000000000000001 R11: 0000000000000283 R12: 0000000000000000
  [  461.137742] R13: 0000000005094df8 R14: 0000000000000001 R15: 0000000000448a10
  [  461.137743] ---[ end trace 187df4cad2bf7649 ]---

This warning happened in the push_dl_task(), because
__add_running_bw()->cpufreq_update_util() is getting the rq_clock of
the later_rq before its update, which takes place at activate_task().
The fix then is to update the rq_clock before calling add_running_bw().

To avoid double rq_clock_update() call, we set ENQUEUE_NOCLOCK flag to
activate_task().

Reported-by: Daniel Casini <daniel.casini@santannapisa.it>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@santannapisa.it>
Fixes: e0367b1267 sched/deadline: Move CPU frequency selection triggering points
Link: http://lkml.kernel.org/r/ca31d073a4788acf0684a8b255f14fea775ccf20.1532077269.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:29:08 +02:00
Isaac J. Manjarres 2610e88946 stop_machine: Disable preemption after queueing stopper threads
This commit:

  9fb8d5dc4b ("stop_machine, Disable preemption when waking two stopper threads")

does not fully address the race condition that can occur
as follows:

On one CPU, call it CPU 3, thread 1 invokes
cpu_stop_queue_two_works(2, 3,...), and the execution is such
that thread 1 queues the works for migration/2 and migration/3,
and is preempted after releasing the locks for migration/2 and
migration/3, but before waking the threads.

Then, On CPU 2, a kworker, call it thread 2, is running,
and it invokes cpu_stop_queue_two_works(1, 2,...), such that
thread 2 queues the works for migration/1 and migration/2.
Meanwhile, on CPU 3, thread 1 resumes execution, and wakes
migration/2 and migration/3. This means that when CPU 2
releases the locks for migration/1 and migration/2, but before
it wakes those threads, it can be preempted by migration/2.

If thread 2 is preempted by migration/2, then migration/2 will
execute the first work item successfully, since migration/3
was woken up by CPU 3, but when it goes to execute the second
work item, it disables preemption, calls multi_cpu_stop(),
and thus, CPU 2 will wait forever for migration/1, which should
have been woken up by thread 2. However migration/1 cannot be
woken up by thread 2, since it is a kworker, so it is affine to
CPU 2, but CPU 2 is running migration/2 with preemption
disabled, so thread 2 will never run.

Disable preemption after queueing works for stopper threads
to ensure that the operation of queueing the works and waking
the stopper threads is atomic.

Co-Developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Co-Developed-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
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: bigeasy@linutronix.de
Cc: gregkh@linuxfoundation.org
Cc: matt@codeblueprint.co.uk
Fixes: 9fb8d5dc4b ("stop_machine, Disable preemption when waking two stopper threads")
Link: http://lkml.kernel.org/r/1531856129-9871-1-git-send-email-isaacm@codeaurora.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:25:08 +02:00
Yi Wang 6cd0c583b0 sched/topology: Check variable group before dereferencing it
The 'group' variable in sched_domain_debug_one() is not checked
when firstly used in cpumask_test_cpu(cpu, sched_group_span(group)),
but it might be NULL (it is checked later in the following while loop)
and may cause NULL pointer dereference.

We need to check it before using to avoid NULL dereference.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1532319547-33335-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:25:07 +02:00
Peter Rosin 62cedf3e60 locking/rtmutex: Allow specifying a subclass for nested locking
Needed for annotating rt_mutex locks.

Tested-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Deepa Dinamani <deepadinamani@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Chang <dpf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Link: http://lkml.kernel.org/r/20180720083914.1950-2-peda@axentia.se
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:22:19 +02:00
David S. Miller 19725496da Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-24 19:21:58 -07:00
Linus Torvalds 0723090656 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Handle stations tied to AP_VLANs properly during mac80211 hw
    reconfig. From Manikanta Pubbisetty.

 2) Fix jump stack depth validation in nf_tables, from Taehee Yoo.

 3) Fix quota handling in aRFS flow expiration of mlx5 driver, from Eran
    Ben Elisha.

 4) Exit path handling fix in powerpc64 BPF JIT, from Daniel Borkmann.

 5) Use ptr_ring_consume_bh() in page pool code, from Tariq Toukan.

 6) Fix cached netdev name leak in nf_tables, from Florian Westphal.

 7) Fix memory leaks on chain rename, also from Florian Westphal.

 8) Several fixes to DCTCP congestion control ACK handling, from Yuchunk
    Cheng.

 9) Missing rcu_read_unlock() in CAIF protocol code, from Yue Haibing.

10) Fix link local address handling with VRF, from David Ahern.

11) Don't clobber 'err' on a successful call to __skb_linearize() in
    skb_segment(). From Eric Dumazet.

12) Fix vxlan fdb notification races, from Roopa Prabhu.

13) Hash UDP fragments consistently, from Paolo Abeni.

14) If TCP receives lots of out of order tiny packets, we do really
    silly stuff. Make the out-of-order queue ending more robust to this
    kind of behavior, from Eric Dumazet.

15) Don't leak netlink dump state in nf_tables, from Florian Westphal.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
  net: axienet: Fix double deregister of mdio
  qmi_wwan: fix interface number for DW5821e production firmware
  ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull
  bnx2x: Fix invalid memory access in rss hash config path.
  net/mlx4_core: Save the qpn from the input modifier in RST2INIT wrapper
  r8169: restore previous behavior to accept BIOS WoL settings
  cfg80211: never ignore user regulatory hint
  sock: fix sg page frag coalescing in sk_alloc_sg
  netfilter: nf_tables: move dumper state allocation into ->start
  tcp: add tcp_ooo_try_coalesce() helper
  tcp: call tcp_drop() from tcp_data_queue_ofo()
  tcp: detect malicious patterns in tcp_collapse_ofo_queue()
  tcp: avoid collapses in tcp_prune_queue() if possible
  tcp: free batches of packets in tcp_prune_ofo_queue()
  ip: hash fragments consistently
  ipv6: use fib6_info_hold_safe() when necessary
  can: xilinx_can: fix power management handling
  can: xilinx_can: fix incorrect clear of non-processed interrupts
  can: xilinx_can: fix RX overflow interrupt not being enabled
  can: xilinx_can: keep only 1-2 frames in TX FIFO to fix TX accounting
  ...
2018-07-24 17:31:47 -07:00
Josh Poimboeuf 73d5e2b472 cpu/hotplug: detect SMT disabled by BIOS
If SMT is disabled in BIOS, the CPU code doesn't properly detect it.
The /sys/devices/system/cpu/smt/control file shows 'on', and the 'l1tf'
vulnerabilities file shows SMT as vulnerable.

Fix it by forcing 'cpu_smt_control' to CPU_SMT_NOT_SUPPORTED in such a
case.  Unfortunately the detection can only be done after bringing all
the CPUs online, so we have to overwrite any previous writes to the
variable.

Reported-by: Joe Mario <jmario@redhat.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Fixes: f048c399e0 ("x86/topology: Provide topology_smt_supported()")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2018-07-24 18:17:40 +02:00
Martin KaFai Lau 6283fa38dc bpf: btf: Ensure the member->offset is in the right order
This patch ensures the member->offset of a struct
is in the correct order (i.e the later member's offset cannot
go backward).

The current "pahole -J" BTF encoder does not generate something
like this.  However, checking this can ensure future encoder
will not violate this.

Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-24 01:20:44 +02:00
Dan Williams 2fa147bdbf mm, dev_pagemap: Do not clear ->mapping on final put
MEMORY_DEVICE_FS_DAX relies on typical page semantics whereby ->mapping
is only ever cleared by truncation, not final put.

Without this fix dax pages may forget their mapping association at the
end of every page pin event.

Move this atypical behavior that HMM wants into the HMM ->page_free()
callback.

Cc: <stable@vger.kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Fixes: d2c997c0f1 ("fs, dax: use page->mapping...")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-23 10:37:39 -07:00
Eric W. Biederman 7673bf553b fork: Unconditionally exit if a fatal signal is pending
In practice this does not change anything as testing for fatal_signal_pending
and exiting for with an error code duplicates the work of the next clause
which recalculates pending signals and then exits fork if any are pending.
In both cases the pending signal will trigger the slow path when existing
to userspace, and the fatal signal will cause do_exit to be called.

The advantage of making this a separate test is that it makes it clear
processing the fatal signal will terminate the fork, and it allows the
rest of the signal logic to be updated without fear that this important
case will be lost.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-23 08:01:10 -05:00
Eric W. Biederman 4ca1d3ee46 fork: Move and describe why the code examines PIDNS_ADDING
Normally this would be something that would be handled by handling
signals that are sent to a group of processes but in this case the
forking process is not a member of the group being signaled.  Thus
special code is needed to prevent a race with pid namespaces exiting,
and fork adding new processes within them.

Move this test up before the signal restart just in case signals are
also pending.  Fatal conditions should take presedence over restarts.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-23 07:57:12 -05:00
Kamalesh Babulal 6e9df95b76 livepatch: Validate module/old func name length
livepatch module author can pass module name/old function name with more
than the defined character limit. With obj->name length greater than
MODULE_NAME_LEN, the livepatch module gets loaded but waits forever on
the module specified by obj->name to be loaded. It also populates a /sys
directory with an untruncated object name.

In the case of funcs->old_name length greater then KSYM_NAME_LEN, it
would not match against any of the symbol table entries. Instead loop
through the symbol table comparing them against a nonexisting function,
which can be avoided.

The same issues apply, to misspelled/incorrect names. At least gatekeep
the modules with over the limit string length, by checking for their
length during livepatch module registration.

Cc: stable@vger.kernel.org
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-07-23 12:12:00 +02:00
Linus Torvalds 48b1db7c7a 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 stop-machine preemption fix and a SCHED_DEADLINE fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix switched_from_dl() warning
  stop_machine: Disable preemption when waking two stopper threads
2018-07-21 17:21:34 -07:00
Linus Torvalds 490fc05386 mm: make vm_area_alloc() initialize core fields
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 15:24:03 -07:00
Linus Torvalds 95faf6992d mm: make vm_area_dup() actually copy the old vma data
.. and re-initialize th eanon_vma_chain head.

This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 14:48:45 -07:00
Linus Torvalds 3928d4f5ee mm: use helper functions for allocating and freeing vm_area structs
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 13:48:51 -07:00
Eric W. Biederman 0729614992 signal: Push pid type down into complete_signal.
This is the bottom and by pushing this down it simplifies the callers
and otherwise leaves things as is.  This is in preparation for allowing
fork to implement better handling of signals set to groups of processes.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 12:57:35 -05:00
Eric W. Biederman 5a883cee74 signal: Push pid type down into __send_signal
This information is already available in the callers and by pushing it
down it makes the code a little clearer, and allows implementing
better handling of signales set to a group of processes in fork.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 12:57:35 -05:00
Eric W. Biederman b213984bd3 signal: Push pid type down into send_signal
This information is already available in the callers and by pushing it
down it makes the code a little clearer, and allows better group
signal behavior in fork.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 12:57:35 -05:00
Eric W. Biederman 40b3b02535 signal: Pass pid type into do_send_sig_info
This passes the information we already have at the call sight into
do_send_sig_info.  Ultimately allowing for better handling of signals
sent to a group of processes during fork.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 12:57:35 -05:00
Eric W. Biederman 0102498083 signal: Pass pid type into group_send_sig_info
This passes the information we already have at the call sight
into group_send_sig_info.  Ultimatelly allowing for to better handle
signals sent to a group of processes.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 12:57:35 -05:00
Eric W. Biederman 24122c7f49 signal: Pass pid and pid type into send_sigqueue
Make the code more maintainable by performing more of the signal
related work in send_sigqueue.

A quick inspection of do_timer_create will show that this code path
does not lookup a thread group by a thread's pid.  Making it safe
to find the task pointed to by it_pid with "pid_task(it_pid, type)";

This supports the changes needed in fork to tell if a signal was sent
to a single process or a group of processes.

Having the pid to task transition in signal.c will also make it easier
to sort out races with de_thread and and the thread group leader
exiting when it comes time to address that.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman 2118e1f53f posix-timers: Noralize good_sigevent
In good_sigevent directly compute the default return value as
"task_tgid(current)".  This is exactly the same as
"task_pid(current->group_leader)" but written more clearly.

In the thread case first compute the thread's pid.  Then veify that
attached to that pid is a thread of the current thread group.

This has the net effect of making the code a little clearer, and
making it obvious that posix timers never look up a process by a the
pid of a thread.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman 6883f81aac pid: Implement PIDTYPE_TGID
Everywhere except in the pid array we distinguish between a tasks pid and
a tasks tgid (thread group id).  Even in the enumeration we want that
distinction sometimes so we have added __PIDTYPE_TGID.  With leader_pid
we almost have an implementation of PIDTYPE_TGID in struct signal_struct.

Add PIDTYPE_TGID as a first class member of the pid_type enumeration and
into the pids array.  Then remove the __PIDTYPE_TGID special case and the
leader_pid in signal_struct.

The net size increase is just an extra pointer added to struct pid and
an extra pair of pointers of an hlist_node added to task_struct.

The effect on code maintenance is the removal of a number of special
cases today and the potential to remove many more special cases as
PIDTYPE_TGID gets used to it's fullest.  The long term potential
is allowing zombie thread group leaders to exit, which will remove
a lot more special cases in the code.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman 2c4704756c pids: Move the pgrp and session pid pointers from task_struct to signal_struct
To access these fields the code always has to go to group leader so
going to signal struct is no loss and is actually a fundamental simplification.

This saves a little bit of memory by only allocating the pid pointer array
once instead of once for every thread, and even better this removes a
few potential races caused by the fact that group_leader can be changed
by de_thread, while signal_struct can not.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman 7a36094d61 pids: Compute task_tgid using signal->leader_pid
The cost is the the same and this removes the need
to worry about complications that come from de_thread
and group_leader changing.

__task_pid_nr_ns has been updated to take advantage of this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman 1fb53567a3 pids: Move task_pid_type into sched/signal.h
The function is general and inline so there is no need
to hide it inside of exit.c

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
David S. Miller eae249b27f Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-07-20

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add sharing of BPF objects within one ASIC: this allows for reuse of
   the same program on multiple ports of a device, and therefore gains
   better code store utilization. On top of that, this now also enables
   sharing of maps between programs attached to different ports of a
   device, from Jakub.

2) Cleanup in libbpf and bpftool's Makefile to reduce unneeded feature
   detections and unused variable exports, also from Jakub.

3) First batch of RCU annotation fixes in prog array handling, i.e.
   there are several __rcu markers which are not correct as well as
   some of the RCU handling, from Roman.

4) Two fixes in BPF sample files related to checking of the prog_cnt
   upper limit from sample loader, from Dan.

5) Minor cleanup in sockmap to remove a set but not used variable,
   from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20 23:58:30 -07:00
Dmitry Torokhov 488dee96bb kernfs: allow creating kernfs objects with arbitrary uid/gid
This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.

When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.

Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20 23:44:35 -07:00
Peter Zijlstra 9407f5a7ee sched/clock: Close a hole in sched_clock_init()
All data required for the 'unstable' sched_clock must be set-up _before_
enabling it -- setting sched_clock_running. This includes the
__gtod_offset but also a recent scd stamp.

Make the gtod-offset update also set the csd stamp -- it requires the
same two clock reads _anyway_. This doesn't hurt in the
sched_clock_tick_stable() case and ensures sched_clock_init() gets
everything set-up before use.

Also switch to unconditional IRQ-disable/enable because the static key
stuff already requires this is not ran with IRQs disabled.

Fixes: 857baa87b6 ("sched/clock: Enable sched clock early")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180720080911.GM2494@hirez.programming.kicks-ass.net
2018-07-20 11:58:00 +02:00
Martin KaFai Lau 36fc3c8c28 bpf: btf: Clean up BTF_INT_BITS() in uapi btf.h
This patch shrinks the BTF_INT_BITS() mask.  The current
btf_int_check_meta() ensures the nr_bits of an integer
cannot exceed 64.  Hence, it is mostly an uapi cleanup.

The actual btf usage (i.e. seq_show()) is also modified
to use u8 instead of u16.  The verification (e.g. btf_int_check_meta())
path stays as is to deal with invalid BTF situation.

Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-20 10:25:48 +02:00
Thomas Gleixner e5af5ff34c Merge tag 'fortglx/4.19/time-part2' of https://git.linaro.org/people/john.stultz/linux into timers/core
Pull the second set of timekeeping things for 4.19 from John Stultz

  * NTP argument clenaups and constification from Ondrej Mosnacek
  * Fix to avoid RTC injecting sleeptime when suspend fails from
    Mukesh Ojha
  * Broading suspsend-timing to include non-stop clocksources that
    aren't currently used for timekeeping from Baolin Wang
2018-07-20 06:43:05 +02:00
Baolin Wang 39232ed5a1 time: Introduce one suspend clocksource to compensate the suspend time
On some hardware with multiple clocksources, we have coarse grained
clocksources that support the CLOCK_SOURCE_SUSPEND_NONSTOP flag, but
which are less than ideal for timekeeping whereas other clocksources
can be better candidates but halt on suspend.

Currently, the timekeeping core only supports timing suspend using
CLOCK_SOURCE_SUSPEND_NONSTOP clocksources if that clocksource is the
current clocksource for timekeeping.

As a result, some architectures try to implement read_persistent_clock64()
using those non-stop clocksources, but isn't really ideal, which will
introduce more duplicate code. To fix this, provide logic to allow a
registered SUSPEND_NONSTOP clocksource, which isn't the current
clocksource, to be used to calculate the suspend time.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
[jstultz: minor tweaks to merge with previous resume changes]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2018-07-19 17:08:52 -07:00
Mukesh Ojha f473e5f467 time: Fix extra sleeptime injection when suspend fails
Currently, there exists a corner case assuming when there is
only one clocksource e.g RTC, and system failed to go to
suspend mode. While resume rtc_resume() injects the sleeptime
as timekeeping_rtc_skipresume() returned 'false' (default value
of sleeptime_injected) due to which we can see mismatch in
timestamps.

This issue can also come in a system where more than one
clocksource are present and very first suspend fails.

Success case:
------------
                                        {sleeptime_injected=false}
rtc_suspend() => timekeeping_suspend() => timekeeping_resume() =>

(sleeptime injected)
 rtc_resume()

Failure case:
------------
         {failure in sleep path} {sleeptime_injected=false}
rtc_suspend()     =>          rtc_resume()

{sleeptime injected again which was not required as the suspend failed}

Fix this by handling the boolean logic properly.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2018-07-19 17:08:51 -07:00
Ondrej Mosnacek 985e695074 timekeeping/ntp: Constify some function arguments
Add 'const' to some function arguments and variables to make it easier
to read the code.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[jstultz: Also fixup pre-existing checkpatch warnings for
 prototype arguments with no variable name]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2018-07-19 17:08:05 -07:00
Pavel Tatashin 46457ea464 sched/clock: Use static key for sched_clock_running
sched_clock_running may be read every time sched_clock_cpu() is called.
Yet, this variable is updated only twice during boot, and never changes
again, therefore it is better to make it a static key.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-25-pasha.tatashin@oracle.com
2018-07-20 00:02:43 +02:00
Pavel Tatashin 857baa87b6 sched/clock: Enable sched clock early
Allow sched_clock() to be used before schec_clock_init() is called.  This
provides a way to get early boot timestamps on machines with unstable
clocks.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-24-pasha.tatashin@oracle.com
2018-07-20 00:02:43 +02:00
Pavel Tatashin 5d2a4e91a5 sched/clock: Move sched clock initialization and merge with generic clock
sched_clock_postinit() initializes a generic clock on systems where no
other clock is provided. This function may be called only after
timekeeping_init().

Rename sched_clock_postinit to generic_clock_inti() and call it from
sched_clock_init(). Move the call for sched_clock_init() until after
time_init().

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-23-pasha.tatashin@oracle.com
2018-07-20 00:02:43 +02:00
Pavel Tatashin 4b1b7f8054 timekeeping: Default boot time offset to local_clock()
read_persistent_wall_and_boot_offset() is called during boot to read
both the persistent clock and also return the offset between the boot time
and the value of persistent clock.

Change the default boot_offset from zero to local_clock() so architectures,
that do not have a dedicated boot_clock but have early sched_clock(), such
as SPARCv9, x86, and possibly more will benefit from this change by getting
a better and more consistent estimate of the boot time without need for an
arch specific implementation.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-17-pasha.tatashin@oracle.com
2018-07-20 00:02:41 +02:00
Pavel Tatashin 3eca993740 timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()
If architecture does not support exact boot time, it is challenging to
estimate boot time without having a reference to the current persistent
clock value. Yet, it cannot read the persistent clock time again, because
this may lead to math discrepancies with the caller of read_boot_clock64()
who have read the persistent clock at a different time.

This is why it is better to provide two values simultaneously: the
persistent clock value, and the boot time.

Replace read_boot_clock64() with:
read_persistent_wall_and_boot_offset(wall_time, boot_offset)

Where wall_time is returned by read_persistent_clock() And boot_offset is
wall_time - boot time, which defaults to 0.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-16-pasha.tatashin@oracle.com
2018-07-20 00:02:40 +02:00
Ondrej Mosnacek 86b2dcd4f0 ntp: Use kstrtos64 for s64 variable
...instead of kstrtol with a dirty cast.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2018-07-19 14:58:37 -07:00
Ondrej Mosnacek 0f9987b63d ntp: Remove redundant arguments
The 'ts' argument of process_adj_status() and process_adjtimex_modes()
is unused and can be safely removed.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2018-07-19 14:58:29 -07:00
Yi Wang 3058758925 timer: Fix coding style
The call to wake_up_nohz_cpu() is incorrectly indented. Remove the surplus TAB.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: zhong.weidong@zte.com.cn
CC: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: https://lkml.kernel.org/r/1531721337-30284-1-git-send-email-wang.yi59@zte.com.cn
2018-07-19 16:52:40 +02:00
Linus Torvalds 024ddc0ce1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Lots of fixes, here goes:

   1) NULL deref in qtnfmac, from Gustavo A. R. Silva.

   2) Kernel oops when fw download fails in rtlwifi, from Ping-Ke Shih.

   3) Lost completion messages in AF_XDP, from Magnus Karlsson.

   4) Correct bogus self-assignment in rhashtable, from Rishabh
      Bhatnagar.

   5) Fix regression in ipv6 route append handling, from David Ahern.

   6) Fix masking in __set_phy_supported(), from Heiner Kallweit.

   7) Missing module owner set in x_tables icmp, from Florian Westphal.

   8) liquidio's timeouts are HZ dependent, fix from Nicholas Mc Guire.

   9) Link setting fixes for sh_eth and ravb, from Vladimir Zapolskiy.

  10) Fix NULL deref when using chains in act_csum, from Davide Caratti.

  11) XDP_REDIRECT needs to check if the interface is up and whether the
      MTU is sufficient. From Toshiaki Makita.

  12) Net diag can do a double free when killing TCP_NEW_SYN_RECV
      connections, from Lorenzo Colitti.

  13) nf_defrag in ipv6 can unnecessarily hold onto dst entries for a
      full minute, delaying device unregister. From Eric Dumazet.

  14) Update MAC entries in the correct order in ixgbe, from Alexander
      Duyck.

  15) Don't leave partial mangles bpf program in jit_subprogs, from
      Daniel Borkmann.

  16) Fix pfmemalloc SKB state propagation, from Stefano Brivio.

  17) Fix ACK handling in DCTCP congestion control, from Yuchung Cheng.

  18) Use after free in tun XDP_TX, from Toshiaki Makita.

  19) Stale ipv6 header pointer in ipv6 gre code, from Prashant Bhole.

  20) Don't reuse remainder of RX page when XDP is set in mlx4, from
      Saeed Mahameed.

  21) Fix window probe handling of TCP rapair sockets, from Stefan
      Baranoff.

  22) Missing socket locking in smc_ioctl(), from Ursula Braun.

  23) IPV6_ILA needs DST_CACHE, from Arnd Bergmann.

  24) Spectre v1 fix in cxgb3, from Gustavo A. R. Silva.

  25) Two spots in ipv6 do a rol32() on a hash value but ignore the
      result. Fixes from Colin Ian King"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (176 commits)
  tcp: identify cryptic messages as TCP seq # bugs
  ptp: fix missing break in switch
  hv_netvsc: Fix napi reschedule while receive completion is busy
  MAINTAINERS: Drop inactive Vitaly Bordug's email
  net: cavium: Add fine-granular dependencies on PCI
  net: qca_spi: Fix log level if probe fails
  net: qca_spi: Make sure the QCA7000 reset is triggered
  net: qca_spi: Avoid packet drop during initial sync
  ipv6: fix useless rol32 call on hash
  ipv6: sr: fix useless rol32 call on hash
  net: sched: Using NULL instead of plain integer
  net: usb: asix: replace mii_nway_restart in resume path
  net: cxgb3_main: fix potential Spectre v1
  lib/rhashtable: consider param->min_size when setting initial table size
  net/smc: reset recv timeout after clc handshake
  net/smc: add error handling for get_user()
  net/smc: optimize consumer cursor updates
  net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
  ipv6: ila: select CONFIG_DST_CACHE
  net: usb: rtl8150: demote allmulti message to dev_dbg()
  ...
2018-07-18 19:32:54 -07:00
Ronny Chevalier baa2a4fdd5 audit: fix use-after-free in audit_add_watch
audit_add_watch stores locally krule->watch without taking a reference
on watch. Then, it calls audit_add_to_parent, and uses the watch stored
locally.

Unfortunately, it is possible that audit_add_to_parent updates
krule->watch.
When it happens, it also drops a reference of watch which
could free the watch.

How to reproduce (with KASAN enabled):

    auditctl -w /etc/passwd -F success=0 -k test_passwd
    auditctl -w /etc/passwd -F success=1 -k test_passwd2

The second call to auditctl triggers the use-after-free, because
audit_to_parent updates krule->watch to use a previous existing watch
and drops the reference to the newly created watch.

To fix the issue, we grab a reference of watch and we release it at the
end of the function.

Signed-off-by: Ronny Chevalier <ronny.chevalier@hp.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-07-18 11:43:36 -04:00
Jakub Kicinski fd4f227dea bpf: offload: allow program and map sharing per-ASIC
Allow programs and maps to be re-used across different netdevs,
as long as they belong to the same struct bpf_offload_dev.
Update the bpf_offload_prog_map_match() helper for the verifier
and export a new helper for the drivers to use when checking
programs at attachment time.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:10:34 +02:00
Jakub Kicinski 602144c224 bpf: offload: keep the offload state per-ASIC
Create a higher-level entity to represent a device/ASIC to allow
programs and maps to be shared between device ports.  The extra
work is required to make sure we don't destroy BPF objects as
soon as the netdev for which they were loaded gets destroyed,
as other ports may still be using them.  When netdev goes away
all of its BPF objects will be moved to other netdevs of the
device, and only destroyed when last netdev is unregistered.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:10:34 +02:00
Jakub Kicinski 9fd7c55591 bpf: offload: aggregate offloads per-device
Currently we have two lists of offloaded objects - programs and maps.
Netdevice unregister notifier scans those lists to orphan objects
associated with device being unregistered.  This puts unnecessary
(even if negligible) burden on all netdev unregister calls in BPF-
-enabled kernel.  The lists of objects may potentially get long
making the linear scan even more problematic.  There haven't been
complaints about this mechanisms so far, but it is suboptimal.

Instead of relying on notifiers, make the few BPF-capable drivers
register explicitly for BPF offloads.  The programs and maps will
now be collected per-device not on a global list, and only scanned
for removal when driver unregisters from BPF offloads.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:10:34 +02:00
Jakub Kicinski 09728266b6 bpf: offload: rename bpf_offload_dev_match() to bpf_offload_prog_map_match()
A set of new API functions exported for the drivers will soon use
'bpf_offload_dev_' as a prefix.  Rename the bpf_offload_dev_match()
which is internal to the core (used by the verifier) to avoid any
confusion.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:10:34 +02:00
Colin Ian King c23e014a4b bpf: sockmap: remove redundant pointer sg
Pointer sg is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'sg' set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:06:24 +02:00
Roman Gushchin 3960f4fd65 bpf: fix rcu annotations in compute_effective_progs()
The progs local variable in compute_effective_progs() is marked
as __rcu, which is not correct. This is a local pointer, which
is initialized by bpf_prog_array_alloc(), which also now
returns a generic non-rcu pointer.

The real rcu-protected pointer is *array (array is a pointer
to an RCU-protected pointer), so the assignment should be performed
using rcu_assign_pointer().

Fixes: 324bda9e6c ("bpf: multi program support for cgroup+bpf")
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:01:54 +02:00
Roman Gushchin d29ab6e1fa bpf: bpf_prog_array_alloc() should return a generic non-rcu pointer
Currently the return type of the bpf_prog_array_alloc() is
struct bpf_prog_array __rcu *, which is not quite correct.
Obviously, the returned pointer is a generic pointer, which
is valid for an indefinite amount of time and it's not shared
with anyone else, so there is no sense in marking it as __rcu.

This change eliminate the following sparse warnings:
kernel/bpf/core.c:1544:31: warning: incorrect type in return expression (different address spaces)
kernel/bpf/core.c:1544:31:    expected struct bpf_prog_array [noderef] <asn:4>*
kernel/bpf/core.c:1544:31:    got void *
kernel/bpf/core.c:1548:17: warning: incorrect type in return expression (different address spaces)
kernel/bpf/core.c:1548:17:    expected struct bpf_prog_array [noderef] <asn:4>*
kernel/bpf/core.c:1548:17:    got struct bpf_prog_array *<noident>
kernel/bpf/core.c:1681:15: warning: incorrect type in assignment (different address spaces)
kernel/bpf/core.c:1681:15:    expected struct bpf_prog_array *array
kernel/bpf/core.c:1681:15:    got struct bpf_prog_array [noderef] <asn:4>*

Fixes: 324bda9e6c ("bpf: multi program support for cgroup+bpf")
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-18 15:01:20 +02:00
Paul Moore 290e44b7dd audit: use ktime_get_coarse_real_ts64() for timestamps
Commit c72051d577 ("audit: use ktime_get_coarse_ts64() for time
access") converted audit's use of current_kernel_time64() to the
new ktime_get_coarse_ts64() function.  Unfortunately this resulted
in incorrect timestamps, e.g. events stamped with the year 1969
despite it being 2018.  This patch corrects this by using
ktime_get_coarse_real_ts64() just like the current_kernel_time64()
wrapper.

Fixes: c72051d577 ("audit: use ktime_get_coarse_ts64() for time access")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-07-17 14:45:08 -04:00
Linus Torvalds 3c53776e29 Mark HI and TASKLET softirq synchronous
Way back in 4.9, we committed 4cd13c21b2 ("softirq: Let ksoftirqd do
its job"), and ever since we've had small nagging issues with it.  For
example, we've had:

  1ff688209e ("watchdog: core: make sure the watchdog_worker is not deferred")
  8d5755b3f7 ("watchdog: softdog: fire watchdog even if softirqs do not get to run")
  217f697436 ("net: busy-poll: allow preemption in sk_busy_loop()")

all of which worked around some of the effects of that commit.

The DVB people have also complained that the commit causes excessive USB
URB latencies, which seems to be due to the USB code using tasklets to
schedule USB traffic.  This seems to be an issue mainly when already
living on the edge, but waiting for ksoftirqd to handle it really does
seem to cause excessive latencies.

Now Hanna Hawa reports that this issue isn't just limited to USB URB and
DVB, but also causes timeout problems for the Marvell SoC team:

 "I'm facing kernel panic issue while running raid 5 on sata disks
  connected to Macchiatobin (Marvell community board with Armada-8040
  SoC with 4 ARMv8 cores of CA72) Raid 5 built with Marvell DMA engine
  and async_tx mechanism (ASYNC_TX_DMA [=y]); the DMA driver (mv_xor_v2)
  uses a tasklet to clean the done descriptors from the queue"

The latency problem causes a panic:

  mv_xor_v2 f0400000.xor: dma_sync_wait: timeout!
  Kernel panic - not syncing: async_tx_quiesce: DMA error waiting for transaction

We've discussed simply just reverting the original commit entirely, and
also much more involved solutions (with per-softirq threads etc).  This
patch is intentionally stupid and fairly limited, because the issue
still remains, and the other solutions either got sidetracked or had
other issues.

We should probably also consider the timer softirqs to be synchronous
and not be delayed to ksoftirqd (since they were the issue with the
earlier watchdog problems), but that should be done as a separate patch.
This does only the tasklet cases.

Reported-and-tested-by: Hanna Hawa <hannah@marvell.com>
Reported-and-tested-by: Josef Griebichler <griebichler.josef@gmx.at>
Reported-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-17 11:12:43 -07:00
Masahiro Yamada c417fbce98 kbuild: move bin2c back to scripts/ from scripts/basic/
Commit 8370edea81 ("bin2c: move bin2c in scripts/basic") moved bin2c
to the scripts/basic/ directory, incorrectly stating "Kexec wants to
use bin2c and it wants to use it really early in the build process.
See arch/x86/purgatory/ code in later patches."

Commit bdab125c93 ("Revert "kexec/purgatory: Add clean-up for
purgatory directory"") and commit d6605b6bbe ("x86/build: Remove
unnecessary preparation for purgatory") removed the redundant
purgatory build magic entirely.

That means that the move of bin2c was unnecessary in the first place.

fixdep is the only host program that deserves to sit in the
scripts/basic/ directory.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-18 01:18:05 +09:00
RAGHU Halharvi d91cfeb0aa genirq: Remove redundant NULL pointer check in __free_irq()
The NULL pointer check in __free_irq() triggers a 'dereference before NULL
pointer check' warning in static code analysis. It turns out that the check
is redundant because all callers have a NULL pointer check already.

Remove it.

Signed-off-by: RAGHU Halharvi <raghuhack78@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20180717102009.7708-1-raghuhack78@gmail.com
2018-07-17 13:35:44 +02:00
Rik van Riel c1a2f7f0c0 mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.

This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.

The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.

For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.

Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.

Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:35:30 +02:00
Andrea Parri 7696f9910a sched/Documentation: Update wake_up() & co. memory-barrier guarantees
Both the implementation and the users' expectation [1] for the various
wakeup primitives have evolved over time, but the documentation has not
kept up with these changes: brings it into 2018.

[1] http://lkml.kernel.org/r/20180424091510.GB4064@hirez.programming.kicks-ass.net

Also applied feedback from Alan Stern.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Akira Yokosawa <akiyks@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Daniel Lustig <dlustig@nvidia.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jade Alglave <j.alglave@ucl.ac.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luc Maranget <luc.maranget@inria.fr>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: parri.andrea@gmail.com
Link: http://lkml.kernel.org/r/20180716180605.16115-12-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:30:34 +02:00
Andrea Parri 3d85b27037 locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock()
There are 11 interpretations of the requirements described in the header
comment for smp_mb__after_spinlock(): one for each LKMM maintainer, and
one currently encoded in the Cat file. Stick to the latter (until a more
satisfactory solution is available).

This also reworks some snippets related to the barrier to illustrate the
requirements and to link them to the idioms which are relied upon at its
call sites.

Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: akiyks@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: stern@rowland.harvard.edu
Link: http://lkml.kernel.org/r/20180716180605.16115-11-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:30:33 +02:00
Andrea Parri 76e079fefc sched/core: Use smp_mb() in wake_woken_function()
wake_woken_function() synchronizes with wait_woken() as follows:

  [wait_woken]                       [wake_woken_function]

  entry->flags &= ~wq_flag_woken;    condition = true;
  smp_mb();                          smp_wmb();
  if (condition)                     wq_entry->flags |= wq_flag_woken;
     break;

This commit replaces the above smp_wmb() with an smp_mb() in order to
guarantee that either wait_woken() sees the wait condition being true
or the store to wq_entry->flags in woken_wake_function() follows the
store in wait_woken() in the coherence order (so that the former can
eventually be observed by wait_woken()).

The commit also fixes a comment associated to set_current_state() in
wait_woken(): the comment pairs the barrier in set_current_state() to
the above smp_wmb(), while the actual pairing involves the barrier in
set_current_state() and the barrier executed by the try_to_wake_up()
in wake_woken_function().

Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-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: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: stern@rowland.harvard.edu
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/20180716180605.16115-10-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:30:33 +02:00
Ingo Molnar 52b544bd38 Linux 4.18-rc5
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Merge tag 'v4.18-rc5' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:27:43 +02:00
Ingo Molnar ea73a5c692 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

- An optimization and a fix for RCU expedited grace periods, with
  the fix being from Boqun Feng.

- Miscellaneous fixes, including a lockdep-annotation fix from
  Boqun Feng.

- SRCU updates.

- Updates to rcutorture and associated scripting.

- Introduce grace-period sequence numbers to the RCU-bh, RCU-preempt,
  and RCU-sched flavors, replacing the old ->gpnum and ->completed
  pair of fields.  This change allows lockless code to obtain the
  complete grace-period state with a single READ_ONCE(), which is
  needed to maintain tolerable lock contention during the upcoming
  consolidation of the three RCU flavors.  Note that grace-period
  sequence numbers are already used by rcu_barrier(), expedited
  RCU grace periods, and SRCU, and are thus already heavily used
  and well-tested.  Joel Fernandes contributed a number of excellent
  fixes and improvements.

- Clean up some grace-period-reporting loose ends, including
  improving the handling of quiescent states from offline CPUs
  and fixing some false-positive WARN_ON_ONCE() invocations.
  (Strictly speaking, the WARN_ON_ONCE() invocations were quite
  correct, but their invariants were (harmlessly) violated by the
  earlier sloppy handling of quiescent states from offline CPUs.)
  In addition, improve grace-period forward-progress guarantees so
  as to allow removal of fail-safe checks that required otherwise
  needless lock acquisitions.  Finally, add more diagnostics to
  help debug the upcoming consolidation of the RCU-bh, RCU-preempt,
  and RCU-sched flavors.

- Additional miscellaneous fixes, including those contributed by
  Byungchul Park, Mauro Carvalho Chehab, Joe Perches, Joel Fernandes,
  Steven Rostedt, Andrea Parri, and Neil Brown.

- Additional torture-test changes, including several contributed by
  Arnd Bergmann and Joel Fernandes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:16:02 +02:00
Mimi Zohar c77b8cdf74 module: replace the existing LSM hook in init_module
Both the init_module and finit_module syscalls call either directly
or indirectly the security_kernel_read_file LSM hook.  This patch
replaces the direct call in init_module with a call to the new
security_kernel_load_data hook and makes the corresponding changes
in SELinux, LoadPin, and IMA.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Mimi Zohar a210fd32a4 kexec: add call to LSM hook in original kexec_load syscall
In order for LSMs and IMA-appraisal to differentiate between kexec_load
and kexec_file_load syscalls, both the original and new syscalls must
call an LSM hook.  This patch adds a call to security_kernel_load_data()
in the original kexec_load syscall.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Kamalesh Babulal 1d98a69e5c livepatch: Remove reliable stacktrace check in klp_try_switch_task()
Support for immediate flag was removed by commit d0807da78e
("livepatch: Remove immediate feature").  We bail out during
patch registration for architectures, those don't support
reliable stack trace. Remove the check in klp_try_switch_task(),
as its not required.

Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-07-16 17:50:33 +02:00
Tobias Tefke 788faab70d perf, tools: Use correct articles in comments
Some of the comments in the perf events code use articles incorrectly,
using 'a' for words beginning with a vowel sound, where 'an' should be
used.

Signed-off-by: Tobias Tefke <tobias.tefke@tutanota.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: jolsa@redhat.com
Cc: namhyung@kernel.org
Link: http://lkml.kernel.org/r/20180709105715.22938-1-tobias.tefke@tutanota.com
[ Fix a few more perf related 'a event' typo fixes from all around the kernel and tooling tree. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16 00:21:03 +02:00
Sebastian Andrzej Siewior af0fffd930 sched/core: Remove get_cpu() from sched_fork()
get_cpu() disables preemption for the entire sched_fork() function.
This get_cpu() was introduced in commit:

  dd41f596cd ("sched: cfs core code")

... which also invoked sched_balance_self() and this function
required preemption do be off.

Today, sched_balance_self() seems to be moved to ->task_fork callback
which is invoked while the ->pi_lock is held.

set_load_weight() could invoke reweight_task() which then via $callchain
might end up in smp_processor_id() but since `update_load' is false
this won't happen.

I didn't find any this_cpu*() or similar usage during the initialisation
of the task_struct.

The `cpu' value (from get_cpu()) is only used later in __set_task_cpu()
while the ->pi_lock lock is held.

Based on this it is possible to remove get_cpu() and use
smp_processor_id() for the `cpu' variable without breaking anything.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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>
Link: http://lkml.kernel.org/r/20180706130615.g2ex2kmfu5kcvlq6@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16 00:16:29 +02:00
Peter Zijlstra 45f5519ec5 sched/cpufreq: Clarify sugov_get_util()
Add a few comments to (hopefully) clarifying some of the magic in
sugov_get_util().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/20180705123617.GM2458@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16 00:16:29 +02:00
Vincent Guittot 5fd778915a sched/sysctl: Remove unused sched_time_avg_ms sysctl
/proc/sys/kernel/sched_time_avg_ms entry is not used anywhere,
remove it.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-12-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16 00:16:29 +02:00
Vincent Guittot bbb62c0b02 sched/core: Remove the rt_avg code
rt_avg is not used anywhere anymore, so we can remove all related code.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-11-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16 00:16:29 +02:00
Vincent Guittot 523e979d31 sched/core: Use PELT for scale_rt_capacity()
The utilization of the CPU by RT, DL and IRQs are now tracked with
PELT so we can use these metrics instead of rt_avg to evaluate the remaining
capacity available for CFS class.

scale_rt_capacity() behavior has been changed and now returns the remaining
capacity available for CFS instead of a scaling factor because RT, DL and
IRQ provide now absolute utilization value.

The same formula as schedutil is used:

  IRQ util_avg + (1 - IRQ util_avg / max capacity ) * /Sum rq util_avg

but the implementation is different because it doesn't return the same value
and doesn't benefit of the same optimization.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-10-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16 00:16:25 +02:00
Vincent Guittot dfa444dc2f sched/cpufreq: Remove sugov_aggregate_util()
There is no reason why sugov_get_util() and sugov_aggregate_util()
were in fact separate functions.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ Rebased after adding irq tracking and fixed some compilation errors. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1530200714-4504-9-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:21 +02:00
Vincent Guittot 9033ea1188 cpufreq/schedutil: Take time spent in interrupts into account
The time spent executing IRQ handlers can be significant but it is not reflected
in the utilization of CPU when deciding to choose an OPP. Now that we have
access to this metric, schedutil can take it into account when selecting
the OPP for a CPU.

RQS utilization don't see the time spend under interrupt context and report
their value in the normal context time window. We need to compensate this when
adding interrupt utilization

The CPU utilization is:

  IRQ util_avg + (1 - IRQ util_avg / max capacity ) * /Sum rq util_avg

A test with iperf on hikey (octo arm64) gives the following speedup:

 iperf -c server_address -r -t 5

 w/o patch		w/ patch
 Tx 276 Mbits/sec	304 Mbits/sec +10%
 Rx 299 Mbits/sec	328 Mbits/sec  +9%

 8 iterations
 stdev is lower than 1%

Only WFI idle state is enabled (shallowest idle state).

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1530200714-4504-8-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:21 +02:00
Vincent Guittot 91c27493e7 sched/irq: Add IRQ utilization tracking
interrupt and steal time are the only remaining activities tracked by
rt_avg. Like for sched classes, we can use PELT to track their average
utilization of the CPU. But unlike sched class, we don't track when
entering/leaving interrupt; Instead, we take into account the time spent
under interrupt context when we update rqs' clock (rq_clock_task).
This also means that we have to decay the normal context time and account
for interrupt time during the update.

That's also important to note that because:

  rq_clock == rq_clock_task + interrupt time

and rq_clock_task is used by a sched class to compute its utilization, the
util_avg of a sched class only reflects the utilization of the time spent
in normal context and not of the whole time of the CPU. The utilization of
interrupt gives an more accurate level of utilization of CPU.

The CPU utilization is:

  avg_irq + (1 - avg_irq / max capacity) * /Sum avg_rq

Most of the time, avg_irq is small and neglictible so the use of the
approximation CPU utilization = /Sum avg_rq was enough.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-7-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:21 +02:00
Vincent Guittot 8cc90515a4 cpufreq/schedutil: Use DL utilization tracking
Now that we have both the DL class bandwidth requirement and the DL class
utilization, we can detect when CPU is fully used so we should run at max.
Otherwise, we keep using the DL bandwidth requirement to define the
utilization of the CPU.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1530200714-4504-6-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:21 +02:00
Vincent Guittot 3727e0e163 sched/dl: Add dl_rq utilization tracking
Similarly to what happens with RT tasks, CFS tasks can be preempted by DL
tasks and the CFS's utilization might no longer describes the real
utilization level.

Current DL bandwidth reflects the requirements to meet deadline when tasks are
enqueued but not the current utilization of the DL sched class. We track
DL class utilization to estimate the system utilization.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-5-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:20 +02:00
Vincent Guittot 3ae117c6cd cpufreq/schedutil: Use RT utilization tracking
Add both CFS and RT utilization when selecting an OPP for CFS tasks as RT
can preempt and steal CFS's running time.

RT util_avg is used to take into account the utilization of RT tasks
on the CPU when selecting OPP. If a RT task migrate, the RT utilization
will not migrate but will decay over time. On an overloaded CPU, CFS
utilization reflects the remaining utilization avialable on CPU. When RT
task migrates, the CFS utilization will increase when tasks will start to
use the newly available capacity. At the same pace, RT utilization will
decay and both variations will compensate each other to keep unchanged
overall utilization and will prevent any OPP drop.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1530200714-4504-4-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:20 +02:00
Vincent Guittot 371bf42732 sched/rt: Add rt_rq utilization tracking
schedutil governor relies on cfs_rq's util_avg to choose the OPP when CFS
tasks are running. When the CPU is overloaded by CFS and RT tasks, CFS tasks
are preempted by RT tasks and in this case util_avg reflects the remaining
capacity but not what CFS want to use. In such case, schedutil can select a
lower OPP whereas the CPU is overloaded. In order to have a more accurate
view of the utilization of the CPU, we track the utilization of RT tasks.
Only util_avg is correctly tracked but not load_avg and runnable_load_avg
which are useless for rt_rq.

rt_rq uses rq_clock_task and cfs_rq uses cfs_rq_clock_task but they are
the same at the root group level, so the PELT windows of the util_sum are
aligned.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-3-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:20 +02:00
Vincent Guittot c079629862 sched/pelt: Move PELT related code in a dedicated file
We want to track rt_rq's utilization as a part of the estimation of the
whole rq's utilization. This is necessary because rt tasks can steal
utilization to cfs tasks and make them lighter than they are.
As we want to use the same load tracking mecanism for both and prevent
useless dependency between cfs and rt code, PELT code is moved in a
dedicated file.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: daniel.lezcano@linaro.org
Cc: dietmar.eggemann@arm.com
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: patrick.bellasi@arm.com
Cc: quentin.perret@arm.com
Cc: rjw@rjwysocki.net
Cc: valentin.schneider@arm.com
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1530200714-4504-2-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:20 +02:00
Quentin Perret 8fe5c5a937 sched/fair: Fix util_avg of new tasks for asymmetric systems
When a new task wakes-up for the first time, its initial utilization
is set to half of the spare capacity of its CPU. The current
implementation of post_init_entity_util_avg() uses SCHED_CAPACITY_SCALE
directly as a capacity reference. As a result, on a big.LITTLE system, a
new task waking up on an idle little CPU will be given ~512 of util_avg,
even if the CPU's capacity is significantly less than that.

Fix this by computing the spare capacity with arch_scale_cpu_capacity().

Signed-off-by: Quentin Perret <quentin.perret@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: morten.rasmussen@arm.com
Cc: patrick.bellasi@arm.com
Link: http://lkml.kernel.org/r/20180612112215.25448-1-quentin.perret@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:20 +02:00
Peter Zijlstra be45bf5395 watchdog/softlockup: Fix cpu_stop_queue_work() double-queue bug
When scheduling is delayed for longer than the softlockup interrupt
period it is possible to double-queue the cpu_stop_work, causing list
corruption.

Cure this by adding a completion to track the cpu_stop_work's
progress.

Reported-by: kernel test robot <lkp@intel.com>
Tested-by: Rong Chen <rong.a.chen@intel.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>
Fixes: 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u" threads with cpu_stop_work")
Link: http://lkml.kernel.org/r/20180713104208.GW2494@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:51:19 +02:00
Juri Lelli e117cb52bd sched/deadline: Fix switched_from_dl() warning
Mark noticed that syzkaller is able to reliably trigger the following warning:

  dl_rq->running_bw > dl_rq->this_bw
  WARNING: CPU: 1 PID: 153 at kernel/sched/deadline.c:124 switched_from_dl+0x454/0x608
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 1 PID: 153 Comm: syz-executor253 Not tainted 4.18.0-rc3+ #29
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   dump_backtrace+0x0/0x458
   show_stack+0x20/0x30
   dump_stack+0x180/0x250
   panic+0x2dc/0x4ec
   __warn_printk+0x0/0x150
   report_bug+0x228/0x2d8
   bug_handler+0xa0/0x1a0
   brk_handler+0x2f0/0x568
   do_debug_exception+0x1bc/0x5d0
   el1_dbg+0x18/0x78
   switched_from_dl+0x454/0x608
   __sched_setscheduler+0x8cc/0x2018
   sys_sched_setattr+0x340/0x758
   el0_svc_naked+0x30/0x34

syzkaller reproducer runs a bunch of threads that constantly switch
between DEADLINE and NORMAL classes while interacting through futexes.

The splat above is caused by the fact that if a DEADLINE task is setattr
back to NORMAL while in non_contending state (blocked on a futex -
inactive timer armed), its contribution to running_bw is not removed
before sub_rq_bw() gets called (!task_on_rq_queued() branch) and the
latter sees running_bw > this_bw.

Fix it by removing a task contribution from running_bw if the task is
not queued and in non_contending state while switched to a different
class.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Reviewed-by: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20180711072948.27061-1-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:47:33 +02:00
Ingo Molnar fdf2ceb7f5 Linux 4.18-rc5
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Merge tag 'v4.18-rc5' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15 23:33:26 +02:00
Isaac J. Manjarres 9fb8d5dc4b stop_machine: Disable preemption when waking two stopper threads
When cpu_stop_queue_two_works() begins to wake the stopper threads, it does
so without preemption disabled, which leads to the following race
condition:

The source CPU calls cpu_stop_queue_two_works(), with cpu1 as the source
CPU, and cpu2 as the destination CPU. When adding the stopper threads to
the wake queue used in this function, the source CPU stopper thread is
added first, and the destination CPU stopper thread is added last.

When wake_up_q() is invoked to wake the stopper threads, the threads are
woken up in the order that they are queued in, so the source CPU's stopper
thread is woken up first, and it preempts the thread running on the source
CPU.

The stopper thread will then execute on the source CPU, disable preemption,
and begin executing multi_cpu_stop(), and wait for an ack from the
destination CPU's stopper thread, with preemption still disabled. Since the
worker thread that woke up the stopper thread on the source CPU is affine
to the source CPU, and preemption is disabled on the source CPU, that
thread will never run to dequeue the destination CPU's stopper thread from
the wake queue, and thus, the destination CPU's stopper thread will never
run, causing the source CPU's stopper thread to wait forever, and stall.

Disable preemption when waking the stopper threads in
cpu_stop_queue_two_works().

Fixes: 0b26351b91 ("stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock")
Co-Developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Co-Developed-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: matt@codeblueprint.co.uk
Cc: bigeasy@linutronix.de
Cc: gregkh@linuxfoundation.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1530655334-4601-1-git-send-email-isaacm@codeaurora.org
2018-07-15 12:12:45 +02:00
Linus Torvalds 3951dbf232 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
 "A clocksource driver fix and a revert"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: arm_arch_timer: Set arch_mem_timer cpumask to cpu_possible_mask
  Revert "tick: Prefer a lower rating device only if it's CPU local device"
2018-07-13 13:36:36 -07:00
Linus Torvalds ae4ea3975d Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rseq fixes from Ingo Molnar:
 "Various rseq ABI fixes and cleanups: use get_user()/put_user(),
  validate parameters and use proper uapi types, etc"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq/selftests: cleanup: Update comment above rseq_prepare_unload
  rseq: Remove unused types_32_64.h uapi header
  rseq: uapi: Declare rseq_cs field as union, update includes
  rseq: uapi: Update uapi comments
  rseq: Use get_user/put_user rather than __get_user/__put_user
  rseq: Use __u64 for rseq_cs fields, validate user inputs
2018-07-13 12:50:42 -07:00
Linus Torvalds 35a84f34cf Joel Fernandes asked to add a feature in tracing that Android had its
own patch internally for. I took it back in 4.13. Now he realizes that
 he had a mistake, and swapped the values from what Android had. This
 means that the old Android tools will break when using a new kernel
 that has the new feature on it.
 
 The options are:
 
  1. To swap it back to what Android wants.
  2. Add a command line option or something to do the swap
  3. Just let Android carry a patch that swaps it back
 
 Since it requires setting a tracing option to enable this anyway,
 I doubt there are other users of this than Android. Thus, I've
 decided to take option 1. If someone else is actually depending on the
 order that is in the kernel, then we will have to revert this change
 and go to option 2 or 3.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW0ib3BQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qpH2APwJb1C72w6/QF9QK8I7HWzK3BN+9KuK
 xfJA+58HXzu7SgD+IXzhXW9tODU+sWbYr9cVOyj2ad6p8CYNDkPlVAJulwM=
 =XJE5
 -----END PGP SIGNATURE-----

Merge tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlet from Steven Rostedt:
 "Joel Fernandes asked to add a feature in tracing that Android had its
  own patch internally for. I took it back in 4.13. Now he realizes that
  he had a mistake, and swapped the values from what Android had. This
  means that the old Android tools will break when using a new kernel
  that has the new feature on it.

  The options are:

   1. To swap it back to what Android wants.
   2. Add a command line option or something to do the swap
   3. Just let Android carry a patch that swaps it back

  Since it requires setting a tracing option to enable this anyway, I
  doubt there are other users of this than Android. Thus, I've decided
  to take option 1. If someone else is actually depending on the order
  that is in the kernel, then we will have to revert this change and go
  to option 2 or 3"

* tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Reorder display of TGID to be after PID
2018-07-13 11:40:11 -07:00
Thomas Gleixner fee0aede6f cpu/hotplug: Set CPU_SMT_NOT_SUPPORTED early
The CPU_SMT_NOT_SUPPORTED state is set (if the processor does not support
SMT) when the sysfs SMT control file is initialized.

That was fine so far as this was only required to make the output of the
control file correct and to prevent writes in that case.

With the upcoming l1tf command line parameter, this needs to be set up
before the L1TF mitigation selection and command line parsing happens.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142323.121795971@linutronix.de
2018-07-13 16:29:56 +02:00
Jiri Kosina 8e1b706b6e cpu/hotplug: Expose SMT control init function
The L1TF mitigation will gain a commend line parameter which allows to set
a combination of hypervisor mitigation and SMT control.

Expose cpu_smt_disable() so the command line parser can tweak SMT settings.

[ tglx: Split out of larger patch and made it preserve an already existing
  	force off state ]

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142323.039715135@linutronix.de
2018-07-13 16:29:55 +02:00
Joel Fernandes (Google) f8494fa3dd tracing: Reorder display of TGID to be after PID
Currently ftrace displays data in trace output like so:

                                       _-----=> irqs-off
                                      / _----=> need-resched
                                     | / _---=> hardirq/softirq
                                     || / _--=> preempt-depth
                                     ||| /     delay
            TASK-PID   CPU    TGID   ||||    TIMESTAMP  FUNCTION
               | |       |      |    ||||       |         |
            bash-1091  [000] ( 1091) d..2    28.313544: sched_switch:

However Android's trace visualization tools expect a slightly different
format due to an out-of-tree patch patch that was been carried for a
decade, notice that the TGID and CPU fields are reversed:

                                       _-----=> irqs-off
                                      / _----=> need-resched
                                     | / _---=> hardirq/softirq
                                     || / _--=> preempt-depth
                                     ||| /     delay
            TASK-PID    TGID   CPU   ||||    TIMESTAMP  FUNCTION
               | |        |      |   ||||       |         |
            bash-1091  ( 1091) [002] d..2    64.965177: sched_switch:

From kernel v4.13 onwards, during which TGID was introduced, tracing
with systrace on all Android kernels will break (most Android kernels
have been on 4.9 with Android patches, so this issues hasn't been seen
yet). From v4.13 onwards things will break.

The chrome browser's tracing tools also embed the systrace viewer which
uses the legacy TGID format and updates to that are known to be
difficult to make.

Considering this, I suggest we make this change to the upstream kernel
and backport it to all Android kernels. I believe this feature is merged
recently enough into the upstream kernel that it shouldn't be a problem.
Also logically, IMO it makes more sense to group the TGID with the
TASK-PID and the CPU after these.

Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org

Cc: jreck@google.com
Cc: tkjos@google.com
Cc: stable@vger.kernel.org
Fixes: 441dae8f2f ("tracing: Add support for display of tgid in trace output")
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-12 19:56:25 -04:00
Paul E. McKenney 18952651da Merge branches 'fixes1.2018.07.12b' and 'torture1.2018.07.12b' into HEAD
fixes1.2018.07.12b: Post-gp_seq miscellaneous fixes
torture1.2018.07.12b: Post-gp_seq torture-test updates
2018-07-12 15:42:41 -07:00
Joel Fernandes (Google) bf5b64355a rcutorture: Fix rcu_barrier successes counter
The rcutorture test module currently increments both successes and error
for the barrier test upon error, which results in misleading statistics
being printed.  This commit therefore changes the code to increment the
success counter only when the test actually passes.

This change was tested by by returning from the barrier callback without
incrementing the callback counter, thus introducing what appeared to
rcutorture to be rcu_barrier() failures.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:08 -07:00
Joel Fernandes (Google) 4babd855fd rcutorture: Add support to detect if boost kthread prio is too low
When rcutorture is built in to the kernel, an earlier patch detects
that and raises the priority of RCU's kthreads to allow rcutorture's
RCU priority boosting tests to succeed.

However, if rcutorture is built as a module, those priorities must be
raised manually via the rcutree.kthread_prio kernel boot parameter.
If this manual step is not taken, rcutorture's RCU priority boosting
tests will fail due to kthread starvation.  One approach would be to
raise the default priority, but that risks breaking existing users.
Another approach would be to allow runtime adjustment of RCU's kthread
priorities, but that introduces numerous "interesting" race conditions.
This patch therefore instead detects too-low priorities, and prints a
message and disables the RCU priority boosting tests in that case.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:08 -07:00
Arnd Bergmann 622be33fcb rcutorture: Use monotonic timestamp for stall detection
The get_seconds() call is deprecated because it overflows on 32-bit
architectures. The algorithm in rcu_torture_stall() can deal with
the overflow, but another problem here is that using a CLOCK_REALTIME
stamp can lead to a false-positive stall warning when a settimeofday()
happens concurrently.

Using ktime_get_seconds() instead avoids those issues and will never
overflow. The added cast to 'unsigned long' however is necessary to
make ULONG_CMP_LT() work correctly.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:07 -07:00
Joel Fernandes (Google) 3b745c8969 rcutorture: Make boost test more robust
Currently, with RCU_BOOST disabled, I get no failures when forcing
rcutorture to test RCU boost priority inversion. The reason seems to be
that we don't check for failures if the callback never ran at all for
the duration of the boost-test loop.

Further, the 'rtb' and 'rtbf' counters seem to be used inconsistently.
'rtb' is incremented at the start of each test and 'rtbf' is incremented
per-cpu on each failure of call_rcu. So its possible 'rtbf' > 'rtb'.

To test the boost with rcutorture, I did following on a 4-CPU x86 machine:

modprobe rcutorture  test_boost=2
sleep 20
rmmod rcutorture

With patch:
rtbf: 8 rtb: 12

Without patch:
rtbf: 0 rtb: 2

In summary this patch:
 - Increments failed and total test counters once per boost-test.
 - Checks for failure cases correctly.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:06 -07:00
Joel Fernandes (Google) 450efca718 rcutorture: Disable RT throttling for boost tests
Currently rcutorture is not able to torture RCU boosting properly. This
is because the rcutorture's boost threads which are doing the torturing
may be throttled due to RT throttling.

This patch makes rcutorture use the right torture technique (unthrottled
rcutorture boost tasks) for torturing RCU so that the test fails
correctly when no boost is available.

Currently this requires accessing sysctl_sched_rt_runtime directly, but
that should be Ok since rcutorture is test code. Such direct access is
also only possible if rcutorture is used as a built-in so make it
conditional on that.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:06 -07:00
Paul E. McKenney bf1bef50be rcutorture: Emphasize testing of single reader protection type
For RCU implementations supporting multiple types of reader protection,
rcutorture currently randomly selects the combinations of types of
protection for each phase of each reader.  The problem with this,
for example, given the four kinds of protection for RCU-sched
(local_irq_disable(), local_bh_disable(), preempt_disable(), and
rcu_read_lock_sched()), the reader will be protected by a single
mechanism only 25% of the time.  We really heavier testing of single
read-side mechanisms.

This commit therefore uses only a single mechanism about 60% of the time,
half of the time explicitly and one-eighth of the time by chance.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:05 -07:00
Paul E. McKenney 2397d072f7 rcutorture: Handle extended read-side critical sections
This commit enables rcutorture to test whether RCU properly aggregates
different types of read-side critical sections into a larger section
covering the set.  It does this by extending an initial read-side
critical section randomly for a random number of extensions.  There is
a new rcu_torture_ops field ->extendable that specifies what extensions
are permitted for a given flavor of RCU (for example, SRCU does not
permit any extensions, while RCU-sched permits all types).  Note that
if a given operation (for example, local_bh_disable()) extends an RCU
read-side critical section, then rcutorture feels free to also start
and end the critical section with that operation's type of disabling.

Disabling operations include local_bh_disable(), local_irq_disable(),
and preempt_disable().  This commit also adds a new "busted_srcud"
torture type, which verifies rcutorture's ability to detect extensions
of RCU read-side critical sections that are not handled.  Gotta test
the test, after all!

Note that it is not legal to invoke local_bh_disable() with interrupts
disabled, and this transition is avoided by overriding the random-number
generator when it wants to call local_bh_disable() while interrupts
are disabled.  The code instead leaves both interrupts and bh/softirq
disabled in this case.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:05 -07:00
Paul E. McKenney 241b42522a rcutorture: Make rcu_torture_timer() use rcu_torture_one_read()
This commit saves a few lines of code by making rcu_torture_timer()
invoke rcu_torture_one_read(), thus completing the consolidation of
code between rcu_torture_timer() and rcu_torture_reader().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:04 -07:00
Paul E. McKenney 3025520ec4 rcutorture: Use per-CPU random state for rcu_torture_timer()
Currently, the rcu_torture_timer() function uses a single global
torture_random_state structure protected by a single global lock.
This conflicts to some extent with performance and scalability,
but even more with the goal of consolidating read-side testing
with rcu_torture_reader().  This commit therefore creates a per-CPU
torture_random_state structure for use by rcu_torture_timer() and
eliminates the lock.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Make rcu_torture_timer_rand static, per 0day Test Robot report. ]
2018-07-12 15:42:04 -07:00
Paul E. McKenney 8da9a59523 rcutorture: Use atomic increment for n_rcu_torture_timers
Currently, rcu_torture_timer() relies on a lock to guard updates to
n_rcu_torture_timers.  Unfortunately, consolidating code with
rcu_torture_reader() will dispense with this lock.  This commit
therefore makes n_rcu_torture_timers be an atomic_long_t and uses
atomic_long_inc() to carry out the update.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:03 -07:00
Paul E. McKenney 6b06aa723e rcutorture: Extract common code from rcu_torture_reader()
This commit extracts the code executed on each pass through the loop
in rcu_torture_reader() into a new rcu_torture_one_read() function.
This new function will also be used by rcu_torture_timer().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:02 -07:00
Paul E. McKenney 2d3625841d rcuperf: Remove unused torturing_tasks() function
The torturing_tasks() function in rcuperf.c is not used, so this commit
removes it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:02 -07:00
Paul E. McKenney 6bea2cc5a9 rcu: Remove rcutorture test version and sequence number
Back when RCU had a debugfs interface, there was a test version and
sequence number that allowed associating debugfs data with a particular
test run, where the test run started with modprobe and ended with rmmod,
which was how tests were run back on the old ABAT system within IBM.
But rcutorture testing no longer runs on ABAT, and there is no longer an
RCU debugfs interface, so there is no longer any need for test versions
and sequence numbers.

This commit therefore removes the rcutorture_record_test_transition()
and rcutorture_record_progress() functions, and along with them the
rcutorture_testseq and rcutorture_vernum variables that they update.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:01 -07:00
Paul E. McKenney 028be12b29 rcutorture: Change units of onoff_interval to jiffies
Some RCU bugs have been sensitive to the frequency of CPU-hotplug
operations, which have been gradually increased over time.  But this
frequency is now at the one-second lower limit that can be specified using
the rcutorture.onoff_interval kernel parameter.  This commit therefore
changes the units of rcutorture.onoff_interval from seconds to jiffies,
and also sets the value specified for this kernel parameter in the TREE03
rcutorture scenario to 200, which is 200 milliseconds for HZ=1000.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:42:01 -07:00
Joel Fernandes (Google) c7cd161ecb rcu: Assign higher prio to RCU threads if rcutorture is built-in
The rcutorture RCU priority boosting tests fail even with CONFIG_RCU_BOOST
set because rcutorture's threads run at the same priority as the default
RCU kthreads (RT class with priority of 1).

This patch checks if RCU torture is built into the kernel and if so,
assigns RT priority 1 to the RCU threads, allowing the rcutorture boost
tests to pass.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:26 -07:00
Paul E. McKenney 52e17ba1d0 srcu: Add grace-period number to rcutorture statistics printout
This commit adds the SRCU grace-period number to the rcutorture statistics
printout, which allows it to be compared to the rcutorture "Writer stall
state" message.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:25 -07:00
Paul E. McKenney 89b4cd4b9e rcu: Print stall-warning NMI dyntick state in hexadecimal
The ->dynticks_nmi_nesting field records the nesting depth of both
interrupt and NMI handlers.  Because the kernel can enter interrupts
and never leave them (and vice versa) and because NMIs can interrupt
manipulation of the ->dynticks_nmi_nesting field, the values in this
field must be both chosen and maniupated very carefully.  As a result,
although the value is zero when the corresponding CPU is executing
neither an interrupt nor an NMI handler, it is 4,611,686,018,427,387,906
on 64-bit systems when there is a single level of interrupt/NMI handling
in progress.

This number is difficult to remember and interpret, so this commit
switches the output to hexadecimal, resulting in the much nicer
0x4000000000000002.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:24 -07:00
Paul E. McKenney 2ee5aca546 rcu: Make rcu_seq_diff() more exact
The current implementatation of rcu_seq_diff() follows tradition in
providing a rough-and-ready approximation of the number of elapsed grace
periods between the two rcu_seq values.  However, this difference is
used to flag RCU-failure "near misses", which can be a valuable debugging
aid, so more exactitude would be an improvement.  This commit therefore
improves the accuracy of rcu_seq_diff().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:23 -07:00
Byungchul Park 67abb96cbf rcu: Check the range of jiffies_till_{first,next}_fqs when setting them
Currently, the range of jiffies_till_{first,next}_fqs are checked and
adjusted on and on in the loop of rcu_gp_kthread on runtime.

However, it's enough to check them only when setting them, not every
time in the loop. So make them handled on a setting time via sysfs.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:22 -07:00
Paul E. McKenney 47199a0812 rcu: Add diagnostics for rcutorture writer stall warning
This commit adds any in-the-future ->gp_seq_needed fields to the
diagnostics for an rcutorture writer stall warning message.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:22 -07:00
Steven Rostedt (VMware) cd23ac8ddb rcu: Add comment to the last sleep in the rcu tasks loop
At the end of rcu_tasks_kthread() there's a lonely
schedule_timeout_uninterruptible() call with no apparent rationale for
its existence. But there is. It is to keep the thread from going into
a tight loop if there's some anomaly. That really needs a comment.

Link: http://lkml.kernel.org/r/20180524223839.GU3803@linux.vnet.ibm.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:21 -07:00
Steven Rostedt (VMware) c03be752d3 rcu: Speed up calling of RCU tasks callbacks
Joel Fernandes found that the synchronize_rcu_tasks() was taking a
significant amount of time. He demonstrated it with the following test:

 # cd /sys/kernel/tracing
 # while [ 1 ]; do x=1; done &
 # echo '__schedule_bug:traceon' > set_ftrace_filter
 # time echo '!__schedule_bug:traceon' > set_ftrace_filter;

real	0m1.064s
user	0m0.000s
sys	0m0.004s

Where it takes a little over a second to perform the synchronize,
because there's a loop that waits 1 second at a time for tasks to get
through their quiescent points when there's a task that must be waited
for.

After discussion we came up with a simple way to wait for holdouts but
increase the time for each iteration of the loop but no more than a
full second.

With the new patch we have:

 # time echo '!__schedule_bug:traceon' > set_ftrace_filter;

real	0m0.131s
user	0m0.000s
sys	0m0.004s

Which drops it down to 13% of what the original wait time was.

Link: http://lkml.kernel.org/r/20180523063815.198302-2-joel@joelfernandes.org
Reported-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Suggested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:21 -07:00
Joel Fernandes (Google) 0d805a70a6 rcu: Add comment documenting how rcu_seq_snap works
rcu_seq_snap may be tricky to decipher. Lets document how it works with
an example to make it easier.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Shrink comment as suggested by Peter Zijlstra. ]
2018-07-12 15:39:20 -07:00
Paul E. McKenney b06ae25a1e rcu: Use RCU CPU stall timeout for rcu_check_gp_start_stall()
Currently, rcu_check_gp_start_stall() waits for one second after the first
request before complaining that a grace period has not yet started.  This
was desirable while testing the conversion from ->future_gp_needed[] to
->gp_seq_needed, but it is a bit on the hair-trigger side for production
use under heavy load.  This commit therefore makes this wait time be
exactly that of the RCU CPU stall warning, allowing easy adjustment of
both timeouts to suit the distribution or installation at hand.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:20 -07:00
Paul E. McKenney 51fbb910f5 rcu: Remove __maybe_unused from rcu_cpu_has_callbacks()
The rcu_cpu_has_callbacks() function is now used in all configurations,
so this commit removes the __maybe_unused.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:19 -07:00
Paul E. McKenney 9622179519 rcu: Remove "inline" from rcu_perf_print_module_parms()
This function is in rcuperf.c, which is not an include file, so there
is no problem dropping the "inline", especially given that this function
is invoked only twice per rcuperf run.  This commit therefore delegates
the inlining decision to the compiler by dropping the "inline".

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:19 -07:00
Paul E. McKenney eac45e586c rcu: Remove "inline" from rcu_torture_print_module_parms()
This function is in rcutorture.c, which is not an include file, so there
is no problem dropping the "inline", especially given that this function
is invoked only twice per rcutorture run.  This commit therefore delegates
the inlining decision to the compiler by dropping the "inline".

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:18 -07:00
Paul E. McKenney 95394e69c4 rcu: Remove "inline" from panic_on_rcu_stall() and rcu_blocking_is_gp()
These functions are in kernel/rcu/tree.c, which is not an include file,
so there is no problem dropping the "inline", especially given that these
functions are nowhere near a fastpath.  This commit therefore delegates
the inlining decision to the compiler by dropping the "inline".

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:18 -07:00
Paul E. McKenney ab6b82147f rcu: Remove unused local variable "cpu"
One danger of using __maybe_unused is that the compiler doesn't yell
at you when you remove the last reference, witness rcu_bind_gp_kthread()
and its local variable "cpu".  This commit removes this local variable.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:17 -07:00
Paul E. McKenney 164ba3fc48 rcu: Remove unused rcu_kick_nohz_cpu() function
The rcu_kick_nohz_cpu() function is no longer used, and the functionality
it used to provide is now provided by a call to resched_cpu() in the
force-quiescent-state function rcu_implicit_dynticks_qs().  This commit
therefore removes rcu_kick_nohz_cpu().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:17 -07:00
Paul E. McKenney c7037ff524 rcu: Clarify and correct the rcu_preempt_qs() header comment
The rcu_preempt_qs() function only applies to the CPU, not the task.
A task really is allowed to invoke this function while in an RCU-preempt
read-side critical section, but only if it has first added itself to
some leaf rcu_node structure's ->blkd_tasks list.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:16 -07:00
Paul E. McKenney 3b57a3994f rcu: Inline rcu_dynticks_momentary_idle() into its sole caller
The rcu_dynticks_momentary_idle() function is invoked only from
rcu_momentary_dyntick_idle(), and neither function is particularly
large.  This commit therefore saves a few lines by inlining
rcu_dynticks_momentary_idle() into rcu_momentary_dyntick_idle().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:16 -07:00
Paul E. McKenney 15651201fa rcu: Mark task as .need_qs less aggressively
If any scheduling-clock interrupt interrupts an RCU-preempt read-side
critical section, the interrupted task's ->rcu_read_unlock_special.b.need_qs
field is set.  This causes the outermost rcu_read_unlock() to incur the
extra overhead of calling into rcu_read_unlock_special().  This commit
reduces that overhead by setting ->rcu_read_unlock_special.b.need_qs only
if the grace period has been in effect for more than one second.

Why one second?  Because this is comfortably smaller than the minimum
RCU CPU stall-warning timeout of three seconds, but long enough that the
.need_qs marking should happen quite rarely.  And if your RCU read-side
critical section has run on-CPU for a full second, it is not unreasonable
to invest some CPU time in ending the grace period quickly.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:15 -07:00
Paul E. McKenney 6f56f714db rcu: Improve RCU-tasks naming and comments
The naming and comments associated with some RCU-tasks code make
the faulty assumption that context switches due to cond_resched()
are voluntary.  As several people pointed out, this is not the case.
This commit therefore updates function names and comments to better
reflect current reality.

Reported-by: Byungchul Park <byungchul.park@lge.com>
Reported-by: Joel Fernandes <joel@joelfernandes.org>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:15 -07:00
Joe Perches a7538352da rcu: Use pr_fmt to prefix "rcu: " to logging output
This commit also adjusts some whitespace while in the area.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Revert string-breaking %s as requested by Andy Shevchenko. ]
2018-07-12 15:39:13 -07:00
Byungchul Park 07f27570dc rcu: Improve rcu_note_voluntary_context_switch() reporting
We expect a quiescent state of TASKS_RCU when cond_resched_tasks_rcu_qs()
is called, no matter whether it actually be scheduled or not. However,
it currently doesn't report the quiescent state when the task enters
into __schedule() as it's called with preempt = true. So make it report
the quiescent state unconditionally when cond_resched_tasks_rcu_qs() is
called.

And in TINY_RCU, even though the quiescent state of rcu_bh also should
be reported when the tick interrupt comes from user, it doesn't. So make
it reported.

Lastly in TREE_RCU, rcu_note_voluntary_context_switch() should be
reported when the tick interrupt comes from not only user but also idle,
as an extended quiescent state.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Simplify rcutiny portion given no RCU-tasks for !PREEMPT. ]
2018-07-12 15:39:12 -07:00
Paul E. McKenney 3949fa9bac rcu: Make rcu_read_unlock_special() static
Because rcu_read_unlock_special() is no longer used outside of
kernel/rcu/tree_plugin.h, this commit makes it static.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:11 -07:00
Paul E. McKenney f2e2df5978 rcu: Add diagnostics for offline CPUs failing to report QS
CPUs are expected to report quiescent states when coming online and
when going offline, and grace-period initialization is supposed to
handle any race conditions where a CPU's ->qsmask bit is set just after
it goes offline.  This commit adds diagnostics for the case where an
offline CPU nevertheless has a grace period waiting on it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:10 -07:00
Paul E. McKenney fea3f222d3 rcu: Record ->gp_state for both phases of grace-period initialization
Grace-period initialization first processes any recent CPU-hotplug
operations, and then initializes state for the new grace period.  These
two phases of initialization are currently not distinguished in debug
prints, but the distinction is valuable in a number of debug situations.
This commit therefore introduces two new values for ->gp_state,
RCU_GP_ONOFF and RCU_GP_INIT, in order to make this distinction.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:09 -07:00
Paul E. McKenney 5773894231 rcu: Add CPU online/offline state to dump_blkd_tasks()
Interactions between CPU-hotplug operations and grace-period
initialization can result in dump_blkd_tasks().  One of the first
debugging actions in this case is to search back in dmesg to work
out which of the affected rcu_node structure's CPUs are online and to
determine the last CPU-hotplug operation affecting any of those CPUs.
This can be laborious and error-prone, especially when console output
is lost.

This commit therefore causes dump_blkd_tasks() to dump the state of
the affected rcu_node structure's CPUs and the last grace period during
which the last offline and online operation affected each of these CPUs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:09 -07:00
Paul E. McKenney ff3cee3908 rcu: Add up-tree information to dump_blkd_tasks() diagnostics
This commit updates dump_blkd_tasks() to print out quiescent-state
bitmasks for the rcu_node structures further up the tree.  This
information helps debugging of interactions between CPU-hotplug
operations and RCU grace-period initialization.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:08 -07:00
Paul E. McKenney e05121ba5b rcu: Remove CPU-hotplug failsafe from force-quiescent-state code path
Now that quiescent states for newly offlined CPUs are reported either
when that CPU goes offline or at the end of grace-period initialization,
the CPU-hotplug failsafe in the force-quiescent-state code path is no
longer needed.

This commit therefore removes this failsafe.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:07 -07:00
Paul E. McKenney 17a8212b8d rcu: Remove failsafe check for lost quiescent state
Now that quiescent-state reporting is fully event-driven, this commit
removes the check for a lost quiescent state from force_qs_rnp().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:06 -07:00
Paul E. McKenney f34f2f5852 rcu: Move grace-period pre-init delay after pre-init
The main race with the early part of grace-period initialization appears
to be with CPU hotplug.  To more fully open this race window, this commit
moves the rcu_gp_slow() from the beginning of the early initialization
loop to follow that loop, thus widening the race window, especially for
the rcu_node structures that are initialized last.  This commit also
expands rcutree.gp_preinit_delay from 3 to 12, giving the same overall
delay in the grace period, but concentrated in the spot where it will
do the most good.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:06 -07:00
Paul E. McKenney 1f3e5f51b9 rcu: Add RCU-preempt check for waiting on newly onlined CPU
RCU should only be waiting on CPUs that were online at the time that the
current grace period started.  Failure to abide by this rule can result
in confusing splats during grace-period cleanup and initialization.
This commit therefore adds a check to RCU-preempt's preempted-task
queuing that checks for waiting on newly onlined CPUs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:05 -07:00
Paul E. McKenney 1e64b15a4b rcu: Fix grace-period hangs due to race with CPU offline
Without special fail-safe quiescent-state-propagation checks, grace-period
hangs can result from the following scenario:

1.	CPU 1 goes offline.

2.	Because CPU 1 is the only CPU in the system blocking the current
	grace period, the grace period ends as soon as
	rcu_cleanup_dying_idle_cpu()'s call to rcu_report_qs_rnp()
	returns.

3.	At this point, the leaf rcu_node structure's ->lock is no longer
	held: rcu_report_qs_rnp() has released it, as it must in order
	to awaken the RCU grace-period kthread.

4.	At this point, that same leaf rcu_node structure's ->qsmaskinitnext
	field still records CPU 1 as being online.  This is absolutely
	necessary because the scheduler uses RCU (in this case on the
	wake-up path while awakening RCU's grace-period kthread), and
	->qsmaskinitnext contains RCU's idea as to which CPUs are online.
	Therefore, invoking rcu_report_qs_rnp() after clearing CPU 1's
	bit from ->qsmaskinitnext would result in a lockdep-RCU splat
	due to RCU being used from an offline CPU.

5.	RCU's grace-period kthread awakens, sees that the old grace period
	has completed and that a new one is needed.  It therefore starts
	a new grace period, but because CPU 1's leaf rcu_node structure's
	->qsmaskinitnext field still shows CPU 1 as being online, this new
	grace period is initialized to wait for a quiescent state from the
	now-offline CPU 1.

6.	Without the fail-safe force-quiescent-state checks, there would
	be no quiescent state from the now-offline CPU 1, which would
	eventually result in RCU CPU stall warnings and memory exhaustion.

It would be good to get rid of the special fail-safe quiescent-state
propagation checks, and thus it would be good to fix things so that
the above scenario cannot happen.  This commit therefore adds a new
->ofl_lock to the rcu_state structure.  This lock is held by rcu_gp_init()
across the applying of buffered online and offline operations to the
rcu_node tree, and it is also held by rcu_cleanup_dying_idle_cpu()
when buffering a new offline operation.  This prevents rcu_gp_init()
from acquiring the leaf rcu_node structure's lock during the interval
between when rcu_cleanup_dying_idle_cpu() invokes rcu_report_qs_rnp(),
which releases ->lock and the re-acquisition of that same lock.
This in turn prevents the failure scenario outlined above, and will
hopefully eventually allow removal of the offline-CPU checks from the
force-quiescent-state code path.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:04 -07:00
Paul E. McKenney ec2c29765a rcu: Fix grace-period hangs from mid-init task resume
Without special fail-safe quiescent-state-propagation checks, grace-period
hangs can result from the following scenario:

1.	A task running on a given CPU is preempted in its RCU read-side
	critical section.

2.	That CPU goes offline, and there are now no online CPUs
	corresponding to that CPU's leaf rcu_node structure.

3.	The rcu_gp_init() function does the first phase of grace-period
	initialization, and sets the aforementioned leaf rcu_node
	structure's ->qsmaskinit field to all zeroes.  Because there
	is a blocked task, it does not propagate the zeroing of either
	->qsmaskinit or ->qsmaskinitnext up the rcu_node tree.

4.	The task resumes on some other CPU and exits its critical section.
	There is no grace period in progress, so the resulting quiescent
	state is not reported up the tree.

5.	The rcu_gp_init() function does the second phase of grace-period
	initialization, which results in the leaf rcu_node structure
	being initialized to expect no further quiescent states, but
	with that structure's parent expecting a quiescent-state report.

	The parent will never receive a quiescent state from this leaf
	rcu_node structure, so the grace period will hang, resulting in
	RCU CPU stall warnings.

It would be good to get rid of the special fail-safe quiescent-state
propagation checks.  This commit therefore checks the leaf rcu_node
structure's ->wait_blkd_tasks field during grace-period initialization.
If this flag is set, the rcu_report_qs_rnp() is invoked to immediately
report the possible quiescent state.  While in the neighborhood, this
commit also report quiescent states for any CPUs that went offline between
the two phases of grace-period initialization, thus reducing grace-period
delays and hopefully eventually allowing removal of offline-CPU checks
from the force-quiescent-state code path.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:04 -07:00
Paul E. McKenney 0b107d24d9 rcu: Suppress false-positive splats from mid-init task resume
Consider the following sequence of events in a PREEMPT=y kernel:

1.	All CPUs corresponding to a given leaf rcu_node structure are
	offline.

2.	The first phase of the rcu_gp_init() function's grace-period
	initialization runs, and sets that rcu_node structure's
	->qsmaskinit to zero, as it should.

3.	One of the CPUs corresponding to that rcu_node structure comes
	back online.  Note that because this CPU came online after the
	grace period started, this grace period can safely ignore this
	newly onlined CPU.

4.	A task running on the newly onlined CPU enters an RCU-preempt
	read-side critical section, and is then preempted.  Because
	the corresponding rcu_node structure's ->qsmask is zero,
	rcu_preempt_ctxt_queue() leaves the rcu_node structure's
	->gp_tasks field NULL, as it should.

5.	The rcu_gp_init() function continues running the second phase of
	grace-period initialization.  The ->qsmask field of the parent of
	the aforementioned leaf rcu_node structure is set to not expect
	a quiescent state from the leaf, as is only right and proper.

	However, when rcu_gp_init() reaches the leaf, it invokes
	rcu_preempt_check_blocked_tasks(), which sees that the leaf's
	->blkd_tasks list is non-empty, and therefore sets the leaf's
	->gp_tasks field to reference the first task on that list.

6.	The grace period ends before the preempted task resumes, which
	is perfectly fine, given that this grace period was under no
	obligation to wait for that task to exit its late-starting
	RCU-preempt read-side critical section.  Unfortunately, the
	leaf's ->gp_tasks field is non-NULL, so rcu_gp_cleanup() splats.
	After all, it appears to rcu_gp_cleanup() that the grace period
	failed to wait for a task that was supposed to be blocking that
	grace period.

This commit avoids this false-positive splat by adding a check of both
->qsmaskinit and ->wait_blkd_tasks to rcu_preempt_check_blocked_tasks().
If both ->qsmaskinit and ->wait_blkd_tasks are zero, then the task must
have entered its RCU-preempt read-side critical section late (after all,
the CPU that it is running on was not online at that time), which means
that the upper-level rcu_node structure won't be waiting for anything
on the leaf anyway.

If ->wait_blkd_tasks is non-zero, then there is at least one task on
ths rcu_node structure's ->blkd_tasks list whose RCU read-side
critical section predates the current grace period.  If ->qsmaskinit
is non-zero, there is at least one CPU that was online at the start
of the current grace period.  Thus, if both are zero, there is nothing
to wait for.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:03 -07:00
Paul E. McKenney 99990da1b3 rcu: Suppress more involved false-positive preempted-task splats
Consider the following sequence of events in a PREEMPT=y kernel:

1.	All but one of the CPUs corresponding to a given leaf rcu_node
	structure go offline.  Each of these CPUs clears its bit in that
	structure's ->qsmaskinitnext field.

2.	A new grace period starts, and rcu_gp_init() scans the leaf
	rcu_node structures, applying CPU-hotplug changes since the
	start of the previous grace period, including those changes in
	#1 above.  This copies each leaf structure's ->qsmaskinitnext
	to its ->qsmask field, which represents the CPUs that this new
	grace period will wait on.  Each copy operation is done holding
	the corresponding leaf rcu_node structure's ->lock, and at the
	end of this scan, rcu_gp_init() holds no locks.

3.	The last CPU corresponding to #1's leaf rcu_node structure goes
	offline, clearing its bit in that structure's ->qsmaskinitnext
	field, but not touching the ->qsmaskinit field.  Note that
	rcu_gp_init() is not currently holding any locks!  This CPU does
	-not- report a quiescent state because the grace period has not
	yet initialized itself sufficiently to have set any bits in any
	of the leaf rcu_node structures' ->qsmask fields.

4.	The rcu_gp_init() function continues initializing the new grace
	period, copying each leaf rcu_node structure's ->qsmaskinit
	field to its ->qsmask field while holding the corresponding ->lock.
	This sets the ->qsmask bit corresponding to #3's CPU.

5.	Before the grace period ends, #3's CPU comes back online.
	Because te grace period has not yet done any force-quiescent-state
	scans (which would report a quiescent state on behalf of any
	offline CPUs), this CPU's ->qsmask bit is still set.

6.	A task running on the newly onlined CPU is preempted while in
	an RCU read-side critical section.  Because this CPU's ->qsmask
	bit is net, not only does this task queue itself on the leaf
	rcu_node structure's ->blkd_tasks list, it also sets that
	structure's ->gp_tasks pointer to reference it.

7.	The grace period started in #1 above comes to an end.  This
	results in rcu_gp_cleanup() being invoked, which, among other
	things, checks to make sure that there are no tasks blocking the
	just-ended grace period, that is, that all ->gp_tasks pointers
	are NULL.  The ->gp_tasks pointer corresponding to the task
	preempted in #3 above is non-NULL, which results in a splat.

This splat is a false positive.  The task's RCU read-side critical
section cannot have begun before the just-ended grace period because
this would mean either: (1) The CPU came online before the grace period
started, which cannot have happened because the grace period started
before that CPU went offline, or (2) The task started its RCU read-side
critical section on some other CPU, but then it would have had to have
been preempted before migrating to this CPU, which would mean that it
would have instead queued itself on that other CPU's rcu_node structure.
RCU's grace periods thus are working correctly.  Or, more accurately,
that remaining bugs in RCU's grace periods are elsewhere.

This commit eliminates this false positive by adding code to the end
of rcu_cpu_starting() that reports a quiescent state to RCU, which has
the side-effect of clearing that CPU's ->qsmask bit, preventing the
above scenario.  This approach has the added benefit of more promptly
reporting quiescent states corresponding to offline CPUs.  Nevertheless,
this commit does -not- remove the need for the force-quiescent-state
scans to check for offline CPUs, given that a CPU might remain offline
indefinitely.  And without the checks in the force-quiescent-state scans,
the grace period would also persist indefinitely, which could result in
hangs or memory exhaustion.

Note well that the call to rcu_report_qs_rnp() reporting the quiescent
state must come -after- the setting of this CPU's bit in the leaf rcu_node
structure's ->qsmaskinitnext field.  Otherwise, lockdep-RCU will complain
bitterly about quiescent states coming from an offline CPU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:03 -07:00
Paul E. McKenney fece27760f rcu: Suppress false-positive preempted-task splats
Consider the following sequence of events in a PREEMPT=y kernel:

1.	All CPUs corresponding to a given rcu_node structure go offline.
	A new grace period starts just after the CPU-hotplug code path
	does its synchronize_rcu() for the last CPU, so at least this
	CPU is present in that structure's ->qsmask.

2.	Before the grace period ends, a CPU comes back online, and not
	just any CPU, but the one corresponding to a non-zero bit in
	the leaf rcu_node structure's ->qsmask.

3.	A task running on the newly onlined CPU is preempted while in
	an RCU read-side critical section.  Because this CPU's ->qsmask
	bit is net, not only does this task queue itself on the leaf
	rcu_node structure's ->blkd_tasks list, it also sets that
	structure's ->gp_tasks pointer to reference it.

4.	The grace period started in #1 above comes to an end.  This
	results in rcu_gp_cleanup() being invoked, which, among other
	things, checks to make sure that there are no tasks blocking the
	just-ended grace period, that is, that all ->gp_tasks pointers
	are NULL.  The ->gp_tasks pointer corresponding to the task
	preempted in #3 above is non-NULL, which results in a splat.

This splat is a false positive.  The task's RCU read-side critical
section cannot have begun before the just-ended grace period because
this would mean either: (1) The CPU came online before the grace period
started, which cannot have happened because the grace period started
before that CPU was all the way offline, or (2) The task started its
RCU read-side critical section on some other CPU, but then it would
have had to have been preempted before migrating to this CPU, which
would mean that it would have instead queued itself on that other CPU's
rcu_node structure.

This commit eliminates this false positive by adding code to the end
of rcu_cleanup_dying_idle_cpu() that reports a quiescent state to RCU,
which has the side-effect of clearing that CPU's ->qsmask bit, preventing
the above scenario.  This approach has the added benefit of more promptly
reporting quiescent states corresponding to offline CPUs.

Note well that the call to rcu_report_qs_rnp() reporting the quiescent
state must come -before- the clearing of this CPU's bit in the leaf
rcu_node structure's ->qsmaskinitnext field.  Otherwise, lockdep-RCU
will complain bitterly about quiescent states coming from an offline CPU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:02 -07:00
Paul E. McKenney 5554788e1d rcu: Suppress false-positive offline-CPU lockdep-RCU splat
The rcu_lockdep_current_cpu_online() function currently checks only the
RCU-sched data structures to determine whether or not RCU believes that a
given CPU is offline.  Unfortunately, there are multiple flavors of RCU,
which means that there is a short window of time during which the various
flavors disagree as to whether or not a given CPU is offline.  This can
result in false-positive lockdep-RCU splats in which some other flavor
of RCU tries to do something based on its view that the CPU is online,
only to get hit with a lockdep-RCU splat because RCU-sched instead
believes that the CPU is offline.

This commit therefore changes rcu_lockdep_current_cpu_online() to scan
all RCU flavors and to consider a given CPU to be online if any of the
RCU flavors believe it to be online, thus preventing these false-positive
splats.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:02 -07:00
Paul E. McKenney 928164351e rcu: Prevent useless FQS scan after all CPUs have checked in
The force_qs_rnp() function checks for ->qsmask being all zero, that is,
all CPUs for the current rcu_node structure having already passed through
quiescent states.  But with RCU-preempt, this is not sufficient to report
quiescent states further up the tree, so there are further checks that
can initiate RCU priority boosting and also for races with CPU-hotplug
operations.  However, if neither of these further checks apply, the code
proceeds to carry out a useless scan of an all-zero ->qsmask.

This commit therefore adds code to release the current rcu_node
structure's lock and continue on to the next rcu_node structure, thereby
avoiding this useless scan.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:01 -07:00
Paul E. McKenney 91f63ced7d rcu: Replace smp_wmb() with smp_store_release() for stall check
This commit gets rid of the smp_wmb() in record_gp_stall_check_time()
in favor of an smp_store_release().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:01 -07:00
Paul E. McKenney 77cfc7bf24 rcu: Fix typo and add additional debug
This commit fixes a typo and adds some additional debugging to the
message emitted when a task blocking the current grace period is listed
as blocking it when either that grace period ends or the next grace
period begins.  This commit also reformats the console message for
readability.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:39:00 -07:00
Paul E. McKenney c74859d1eb rcu: Make rcu_report_unblock_qs_rnp() warn on violated preconditions
If rcu_report_unblock_qs_rnp() is invoked on something other than
preemptible RCU or if there are still preempted tasks blocking the
current grace period, something went badly wrong in the caller.
This commit therefore adds WARN_ON_ONCE() to these conditions, but
leaving the legitimate reason for early exit (rnp->qsmask != 0)
unwarned.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-07-12 15:38:59 -07:00