Commit Graph

18626 Commits

Author SHA1 Message Date
Thomas Gleixner 48f18fd6ad timekeeping: Use ktime_get_boottime() for get_monotonic_boottime()
get_monotonic_boottime() is not used in fast pathes, so the extra
timespec conversion is not problematic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:47 -07:00
Thomas Gleixner 250fade8af timekeeping: Remove monotonic_to_bootbased
No more users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:46 -07:00
Steven Rostedt (Red Hat) 0162d621dd ftrace: Rename ftrace_ops field from trampolines to nr_trampolines
Having two fields within the same struct that is off by one character
can be confusing and error prone. Rename the counter "trampolines"
to "nr_trampolines" to explicitly show it is a counter and not to
be confused by the "trampoline" field.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-23 15:03:00 -04:00
Thomas Gleixner 68f6783d28 delayacct: Remove braindamaged type conversions
Converting cputime to timespec and timespec to nanoseconds makes no
sense. Use cputime_to_ns() and be done with it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:06 -07:00
Thomas Gleixner 9667a23db0 delayacct: Make accounting nanosecond based
Kill the timespec juggling and calculate with plain nanoseconds.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:06 -07:00
Thomas Gleixner ccbf62d8a2 sched: Make task->start_time nanoseconds based
Simplify the timespec to nsec/usec conversions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:05 -07:00
Thomas Gleixner 57e0be041d sched: Make task->real_start_time nanoseconds based
Simplify the only user of this data by removing the timespec
conversion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:05 -07:00
Thomas Gleixner d560fed6ab time: Export nsecs_to_jiffies()
Required for moving drivers to the nanosecond based interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:04 -07:00
Thomas Gleixner dcaab54e34 timekeeping: Remove ktime_get_monotonic_offset()
No more users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:03 -07:00
Thomas Gleixner 9a6b51976e timekeeping: Provide ktime_mono_to_any()
ktime based conversion function to map a monotonic time stamp to a
different CLOCK.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:01 -07:00
Thomas Gleixner 48064f5f67 timekeeping; Use ktime based data for ktime_get_update_offsets_tick()
No need to juggle with timespecs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:01 -07:00
Thomas Gleixner a37c0aad60 timekeeping: Use ktime_t data for ktime_get_update_offsets_now()
No need to juggle with timespecs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:00 -07:00
Thomas Gleixner afab07c0e9 timekeeping: Use ktime_t based data for ktime_get_clocktai()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:00 -07:00
Thomas Gleixner b82c817e2d timekeeping; Use ktime_t based data for ktime_get_boottime()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:59 -07:00
Thomas Gleixner f5264d5d5a timekeeping: Use ktime_t based data for ktime_get_real()
Speed up the readout.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:59 -07:00
Thomas Gleixner 0077dc60f2 timekeeping: Provide ktime_get_with_offset()
Provide a helper function which lets us implement ktime_t based
interfaces for real, boot and tai clocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:58 -07:00
Thomas Gleixner a016a5bd62 timekeeping: Use ktime_t based data for ktime_get()
Speed up ktime_get() by using ktime_t based data. Text size shrinks by
64 bytes on x8664.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:58 -07:00
Thomas Gleixner 7c032df557 timekeeping: Provide internal ktime_t based data
The ktime_t based interfaces are used a lot in performance critical
code pathes. Add ktime_t based data so the interfaces don't have to
convert from the xtime/timespec based data.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:57 -07:00
Thomas Gleixner f111adfdd7 timekeeping: Use timekeeping_update() instead of memcpy()
We already have a function which does the right thing, that also makes
sure that the coming ktime_t based cached values are getting updated.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:57 -07:00
Thomas Gleixner 3fdb14fd1d timekeeping: Cache optimize struct timekeeper
struct timekeeper is quite badly sorted for the hot readout path. Most
time access functions need to load two cache lines.

Rearrange it so ktime_get() and getnstimeofday() are happy with a
single cache line.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:56 -07:00
Thomas Gleixner c905fae43f timekeeper: Move tk_xtime to core code
No users outside of the core.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:55 -07:00
Thomas Gleixner d6d29896c6 timekeeping: Provide timespec64 based interfaces
To convert callers of the core code to timespec64 we need to provide
the proper interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:55 -07:00
Thomas Gleixner 8b094cd03b time: Consolidate the time accessor prototypes
Right now we have time related prototypes in 3 different header
files. Move it to a single timekeeping header file and move the core
internal stuff into a core private header.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:54 -07:00
John Stultz 7d489d15ce timekeeping: Convert timekeeping core to use timespec64s
Convert the core timekeeping logic to use timespec64s. This moves the
2038 issues out of the core logic and into all of the accessor
functions.

Future changes will need to push the timespec64s out to all
timekeeping users, but that can be done interface by interface.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:54 -07:00
John Stultz 49cd6f8699 time: More core infrastructure for timespec64
Helper and conversion functions for timespec64.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:17:53 -07:00
Thomas Gleixner 166afb6451 ktime: Sanitize ktime_to_us/ms conversion
With the plain nanoseconds based ktime_t we can simply use
ktime_divns() instead of going through loops and hoops of
timespec/timeval conversion.

Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:16:50 -07:00
John Stultz 24e4a8c3e8 ktime: Kill non-scalar ktime_t implementation for 2038
The non-scalar ktime_t implementation is basically a timespec
which has to be changed to support dates past 2038 on 32bit
systems.

This patch removes the non-scalar ktime_t implementation, forcing
the scalar s64 nanosecond version on all architectures.

This may have additional performance overhead on some 32bit
systems when converting between ktime_t and timespec structures,
however the majority of 32bit systems (arm and i386) were already
using scalar ktime_t, so no performance regressions will be seen
on those platforms.

On affected platforms, I'm open to finding optimizations, including
avoiding converting to timespecs where possible.

[ tglx: We can now cleanup the ktime_t.tv64 mess, but thats a
  different issue and we can throw a coccinelle script at it ]

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:16:50 -07:00
John Stultz 76f4108892 hrtimer: Cleanup hrtimer accessors to the timekepeing state
Rather then having two similar but totally different implementations
that provide timekeeping state to the hrtimer code, try to unify the
two implementations to be more simliar.

Thus this clarifies ktime_get_update_offsets to
ktime_get_update_offsets_now and changes get_xtime...  to
ktime_get_update_offsets_tick.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:16:50 -07:00
Thomas Gleixner e06fde37b8 timekeeping: Simplify arch_gettimeoffset()
Provide a default stub function instead of having the extra
conditional. Cuts binary size on a m68k build by ~100 bytes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:16:50 -07:00
David Riley e704f93af5 kernel: time: Add udelay_test module to validate udelay
Create a module that allows udelay() to be executed to ensure that
it is delaying at least as long as requested (with a little bit of
error allowed).

There are some configurations which don't have reliably udelay
due to using a loop delay with cpufreq changes which should use
a counter time based delay instead.  This test aims to identify
those configurations where timing is unreliable.

Signed-off-by: David Riley <davidriley@chromium.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:16:35 -07:00
Lai Jiangshan ddcb57e2ed workqueue: use nr_node_ids instead of wq_numa_tbl_len
They are the same and nr_node_ids is provided by the memory subsystem.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 12:10:39 -04:00
Lai Jiangshan 3fb1823c09 workqueue: remove the misnamed out_unlock label in get_unbound_pool()
After the locking was moved up to the caller of the get_unbound_pool(),
out_unlock label doesn't need to do any unlock operation and the name
became bad, so we just remove this label, and the only usage-site
"goto out_unlock" is subsituted to "return pool".

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 12:10:39 -04:00
Lai Jiangshan 29b1cb416a workqueue: remove the stale comment in pwq_unbound_release_workfn()
In 75ccf5950f ("workqueue: prepare flush_workqueue() for dynamic
creation and destrucion of unbound pool_workqueues"), a comment
about the synchronization for the pwq in pwq_unbound_release_workfn()
was added. The comment claimed the flush_mutex wasn't strictly
necessary, it was correct in that time, due to the pwq was protected
by workqueue_lock.

But it is incorrect now since the wq->flush_mutex was renamed to
wq->mutex and workqueue_lock was removed, the wq->mutex is strictly
needed. But the comment was miss-updated when the synchronization
was changed.

This patch removes the incorrect comments and doesn't add any new
comment to explain why wq->mutex is needed here, which is definitely
obvious and wq->pwqs_node has "WQ" notation in its definition which is
better comment.

The old commit mentioned above also introduced a comment in link_pwq()
about the synchronization. This comment is also removed in this patch
since the whole link_pwq() is proteced by wq->mutex.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 12:10:39 -04:00
Lai Jiangshan 13b1d625ef workqueue: move rescuer pool detachment to the end
In 51697d3939 ("workqueue: use generic attach/detach routine for
rescuers"), The rescuer detaches itself from the pool before put_pwq()
so that the put_unbound_pool() will not destroy the rescuer-attached
pool.

It is unnecessary.  worker_detach_from_pool() can be used as the last
statement to access to the pool just like the regular workers,
put_unbound_pool() will wait for it to detach and then free the pool.

So we move the worker_detach_from_pool() down, make it coincide with
the regular workers.

tj: Minor description update.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 12:10:39 -04:00
Lai Jiangshan 051e185010 workqueue: unfold start_worker() into create_worker()
Simply unfold the code of start_worker() into create_worker() and
remove the original start_worker() and create_and_start_worker().

The only trade-off is the introduced overhead that the pool->lock
is released and regrabbed after the newly worker is started.
The overhead is acceptible since the manager is slow path.

And because this new locking behavior, the newly created worker
may grab the lock earlier than the manager and go to process
work items. In this case, the recheck need_to_create_worker() may be
true as expected and the manager goes to restart which is the
correct behavior.

tj: Minor updates to description and comments.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 12:10:39 -04:00
Lai Jiangshan 228f1d0018 workqueue: remove @wakeup from worker_set_flags()
worker_set_flags() has only two callers, each specifying %true and
%false for @wakeup.  Let's push the wake up to the caller and remove
@wakeup from worker_set_flags().  The caller can use the following
instead if wakeup is necessary:

	worker_set_flags();
	if (need_more_worker(pool))
 		wake_up_worker(pool);

This makes the code simpler.  This patch doesn't introduce behavior
changes.

tj: Updated description and comments.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 12:08:36 -04:00
Lai Jiangshan a489a03eca workqueue: remove an unneeded UNBOUND test before waking up the next worker
In process_one_work():

	if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
		wake_up_worker(pool);

the first test is unneeded.  Even if the first test is removed, it
doesn't affect the wake-up logic for WORKER_UNBOUND, and it will not
introduce any useless wake-ups for normal per-cpu workers since
nr_running is always >= 1.  It will introduce useless/redundant
wake-ups for CPU_INTENSIVE, but this case is rare and the next patch
will also remove this redundant wake-up.

tj: Minor updates to the description and comment.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-22 10:37:52 -04:00
Tony Luck 58d4e21e50 tracing: Fix wraparound problems in "uptime" trace clock
The "uptime" trace clock added in:

    commit 8aacf017b0
    tracing: Add "uptime" trace clock that uses jiffies

has wraparound problems when the system has been up more
than 1 hour 11 minutes and 34 seconds. It converts jiffies
to nanoseconds using:
        (u64)jiffies_to_usecs(jiffy) * 1000ULL
but since jiffies_to_usecs() only returns a 32-bit value, it
truncates at 2^32 microseconds.  An additional problem on 32-bit
systems is that the argument is "unsigned long", so fixing the
return value only helps until 2^32 jiffies (49.7 days on a HZ=1000
system).

Avoid these problems by using jiffies_64 as our basis, and
not converting to nanoseconds (we do convert to clock_t because
user facing API must not be dependent on internal kernel
HZ values).

Link: http://lkml.kernel.org/p/99d63c5bfe9b320a3b428d773825a37095bf6a51.1405708254.git.tony.luck@intel.com

Cc: stable@vger.kernel.org # 3.10+
Fixes: 8aacf017b0 "tracing: Add "uptime" trace clock that uses jiffies"
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-21 09:56:12 -04:00
Linus Torvalds d057190925 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "The locking department delivers:

   - A rather large and intrusive bundle of fixes to address serious
     performance regressions introduced by the new rwsem / mcs
     technology.  Simpler solutions have been discussed, but they would
     have been ugly bandaids with more risk than doing the right thing.

   - Make the rwsem spin on owner technology opt-in for architectures
     and enable it only on the known to work ones.

   - A few fixes to the lockdep userspace library"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER
  locking/mutex: Disable optimistic spinning on some architectures
  locking/rwsem: Reduce the size of struct rw_semaphore
  locking/rwsem: Rename 'activity' to 'count'
  locking/spinlocks/mcs: Micro-optimize osq_unlock()
  locking/spinlocks/mcs: Introduce and use init macro and function for osq locks
  locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead
  locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node()
  locking/rwsem: Allow conservative optimistic spinning when readers have lock
  tools/liblockdep: Account for bitfield changes in lockdeps lock_acquire
  tools/liblockdep: Remove debug print left over from development
  tools/liblockdep: Fix comparison of a boolean value with a value of 2
2014-07-19 06:27:55 -10:00
Linus Torvalds d1743b810d Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
 "Prevent a possible divide by zero in the debugging code"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix possible divide by zero in avg_atom() calculation
2014-07-19 06:26:43 -10:00
Linus Torvalds b495c23cd4 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
 "A single fix for a long standing issue in the alarm timer subsystem,
  which was noticed recently when people finally started to use alarm
  timers for serious work"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  alarmtimer: Fix bug where relative alarm timers were treated as absolute
2014-07-19 06:25:03 -10:00
Linus Torvalds da5b99b454 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU fixes from Thomas Gleixner:
 "Two RCU patches:
   - Address a serious performance regression on open/close caused by
     commit ac1bea8578 ("Make cond_resched() report RCU quiescent
     states")
   - Export RCU debug functions.  Not a regression, but enablement to
     address a serious recursion bug in the sl*b allocators in 3.17"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Reduce overhead of cond_resched() checks for RCU
  rcu: Export debug_init_rcu_head() and and debug_init_rcu_head()
2014-07-19 06:23:27 -10:00
Thomas Gleixner 1b0733837a irqchip core changes for v3.17 (round #3)
- gic
    - Add GICv3 driver
 
  - atmel
    - Move atmel aic driver from arch code to irqchip/
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Merge tag 'irqchip-core-3.17-3' of git://git.infradead.org/users/jcooper/linux into irq/core

irqchip core changes for v3.17 (round #3) from Jason Cooper
 * gic: Add GICv3 driver
 * atmel: Move atmel aic driver from arch code to irqchip/
2014-07-19 10:14:55 +02:00
Linus Torvalds 084c9cac39 ACPI and power management fixes for 3.16-rc6
- Fix for a recently introduced NULL pointer dereference in the core
    system suspend code occuring when platforms without ACPI attempt to
    use the "freeze" sleep state from Zhang Rui.
 
  - Fix for a recently introduced build warning in cpufreq headers from
    Brian W Hart.
 
  - Fix for a 3.13 cpufreq regression related to sysem resume that
    triggers on some systems with multiple CPU clusters from Viresh Kumar.
 
  - Fix for a 3.4 regression in request_firmware() resulting in
    WARN_ON()s on some systems during system resume from Takashi Iwai.
 
  - Revert of the ACPI video commit that changed the default value of
    the video.brightness_switch_enabled command line argument to 0 as
    it has been reported to break existing setups.
 
  - ACPI device enumeration documentation update to take recent code
    changes into account and make the documentation match the code again
    from Darren Hart.
 
  - Fixes for the sa1110, imx6q, kirkwood, and cpu0 cpufreq drivers
    from Linus Walleij, Nicolas Del Piano, Quentin Armitage, Viresh Kumar.
 
  - New ACPI video blacklist entry for HP ProBook 4540s from Hans de Goede.
 
 /
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Merge tag 'pm+acpi-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:
 "These are a few recent regression fixes, a revert of the ACPI video
  commit I promised, a system resume fix related to request_firmware(),
  an ACPI video quirk for one more Win8-oriented BIOS, an ACPI device
  enumeration documentation update and a few fixes for ARM cpufreq
  drivers.

  Specifics:

   - Fix for a recently introduced NULL pointer dereference in the core
     system suspend code occuring when platforms without ACPI attempt to
     use the "freeze" sleep state from Zhang Rui.

   - Fix for a recently introduced build warning in cpufreq headers from
     Brian W Hart.

   - Fix for a 3.13 cpufreq regression related to sysem resume that
     triggers on some systems with multiple CPU clusters from Viresh
     Kumar.

   - Fix for a 3.4 regression in request_firmware() resulting in
     WARN_ON()s on some systems during system resume from Takashi Iwai.

   - Revert of the ACPI video commit that changed the default value of
     the video.brightness_switch_enabled command line argument to 0 as
     it has been reported to break existing setups.

   - ACPI device enumeration documentation update to take recent code
     changes into account and make the documentation match the code
     again from Darren Hart.

   - Fixes for the sa1110, imx6q, kirkwood, and cpu0 cpufreq drivers
     from Linus Walleij, Nicolas Del Piano, Quentin Armitage, Viresh
     Kumar.

   - New ACPI video blacklist entry for HP ProBook 4540s from Hans de
     Goede"

* tag 'pm+acpi-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: make table sentinel macros unsigned to match use
  cpufreq: move policy kobj to policy->cpu at resume
  cpufreq: cpu0: OPPs can be populated at runtime
  cpufreq: kirkwood: Reinstate cpufreq driver for ARCH_KIRKWOOD
  cpufreq: imx6q: Select PM_OPP
  cpufreq: sa1110: set memory type for h3600
  ACPI / video: Add use_native_backlight quirk for HP ProBook 4540s
  PM / sleep: fix freeze_ops NULL pointer dereferences
  PM / sleep: Fix request_firmware() error at resume
  Revert "ACPI / video: change acpi-video brightness_switch_enabled default to 0"
  ACPI / documentation: Remove reference to acpi_platform_device_ids from enumeration.txt
2014-07-18 20:28:27 -10:00
Steven Rostedt (Red Hat) ba1afef6a4 tracing: Convert local function_graph functions to static
Local functions should be static.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 21:16:06 -04:00
Lai Jiangshan d8ca83e68c workqueue: wake regular worker if need_more_worker() when rescuer leave the pool
We don't need to wake up regular worker when nr_running==1,
so need_more_worker() is sufficient here.

And need_more_worker() gives us better readability due to the name of
"keep_working()" implies the rescuer should keep working now but
the rescuer is actually leaving.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-18 18:46:11 -04:00
Wang Nan b972cc58ce ftrace: Do not copy old hash when resetting
Do not waste time copying the old hash if the hash is going to be
reset. Just allocate a new hash and free the old one, as that is
the same result as copying te old one and then resetting it.

Link: http://lkml.kernel.org/p/1405384820-48837-1-git-send-email-wangnan0@huawei.com

Signed-off-by: Wang Nan <wangnan0@huawei.com>
[ SDR: Removed unused ftrace_filter_reset() function ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 17:47:04 -04:00
Stanislav Fomichev 6508fa761c tracing: let user specify tracing_thresh after selecting function_graph
Currently, tracing_thresh works only if we specify it before selecting
function_graph tracer. If we do the opposite, tracing_thresh will change
it's value, but it will not be applied.
To fix it, we add update_thresh callback which is called whenever
tracing_thresh is updated and for function_graph tracer we register
handler which reinitializes tracer depending on tracing_thresh.

Link: http://lkml.kernel.org/p/20140718111727.GA3206@stfomichev-desktop.yandex.net

Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 15:48:52 -04:00
Corey Minyard 021c5b3445 ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on()
The code for resizing the trace ring buffers has to run the per-cpu
resize on the CPU itself.  The code was using preempt_off() and
running the code for the current CPU directly, otherwise calling
schedule_work_on().

At least on RT this could result in the following:

|BUG: sleeping function called from invalid context at kernel/rtmutex.c:673
|in_atomic(): 1, irqs_disabled(): 0, pid: 607, name: bash
|3 locks held by bash/607:
|CPU: 0 PID: 607 Comm: bash Not tainted 3.12.15-rt25+ #124
|(rt_spin_lock+0x28/0x68)
|(free_hot_cold_page+0x84/0x3b8)
|(free_buffer_page+0x14/0x20)
|(rb_update_pages+0x280/0x338)
|(ring_buffer_resize+0x32c/0x3dc)
|(free_snapshot+0x18/0x38)
|(tracing_set_tracer+0x27c/0x2ac)

probably via
|cd /sys/kernel/debug/tracing/
|echo 1 > events/enable ; sleep 2
|echo 1024 > buffer_size_kb

If we just always use schedule_work_on(), there's no need for the
preempt_off().  So do that.

Link: http://lkml.kernel.org/p/1405537633-31518-1-git-send-email-cminyard@mvista.com

Reported-by: Stanislav Meduna <stano@meduna.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 13:58:12 -04:00
Steven Rostedt (Red Hat) 3a636388ba tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST
All users of function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST have
been removed. We can safely remove them from the kernel.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 13:58:12 -04:00
Steven Rostedt (Red Hat) 1d48d5960f ftrace: Remove function_trace_stop check from list func
function_trace_stop is no longer used to stop function tracing.
Remove the check from __ftrace_ops_list_func().

Also, call FTRACE_WARN_ON() instead of setting function_trace_stop
if a ops has no func to call.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 13:57:00 -04:00
Steven Rostedt (Red Hat) 1820122a76 ftrace: Do no disable function tracing on enabling function tracing
When function tracing is being updated function_trace_stop is set to
keep from tracing the updates. This was fine when function tracing
was done from stop machine. But it is no longer done that way and
this can cause real tracing to be missed.

Remove it.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 13:56:59 -04:00
Steven Rostedt (Red Hat) 545d47b8f3 ftrace-graph: Remove usage of ftrace_stop() in ftrace_graph_stop()
All archs now use ftrace_graph_is_dead() to stop function graph
tracing. Remove the usage of ftrace_stop() as that is no longer
needed.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 13:56:58 -04:00
Masami Hiramatsu d81b4253b0 kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64
On ia64 and ppc64, function pointers do not point to the
entry address of the function, but to the address of a
function descriptor (which contains the entry address and misc
data).

Since the kprobes code passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors,
such as:

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  [...]

To fix this bug, use arch_deref_entry_point() to get the
function entry address for kallsyms_lookup_size_offset()
instead of the raw function pointer.

Suzuki also pointed out that blacklist entries should also
be updated as well.

Reported-by: Tony Luck <tony.luck@gmail.com>
Fixed-by: Suzuki K. Poulose <suzuki@in.ibm.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: sparse@chrisli.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: akataria@vmware.com
Cc: anil.s.keshavamurthy@intel.com
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Kevin Hao <haokexin@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: rdunlap@infradead.org
Cc: dl9pf@gmx.de
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20140717114411.13401.2632.stgit@kbuild-fedora.novalocal
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-18 06:23:40 +02:00
Linus Torvalds 22d368544b A few more fixes for ftrace infrastructure.
I was cleaning out my INBOX and found two fixes from zhangwei from
 a year ago that were lost in my mail. These fix an inconsistency between
 trace_puts() and the way trace_printk() works. The reason this is
 important to fix is because when trace_printk() doesn't have any
 arguments, it turns into a trace_puts(). Not being able to enable a
 stack trace against trace_printk() because it does not have any arguments
 is quite confusing. Also, the fix is rather trivial and low risk.
 
 While porting some changes to PowerPC I discovered that it still has
 the function graph tracer filter bug that if you also enable stack tracing
 the function graph tracer filter is ignored. I fixed that up.
 
 Finally, Martin Lau, fixed a bug that would cause readers of the
 ftrace ring buffer to block forever even though it was suppose to be
 NONBLOCK.
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Merge tag 'trace-fixes-v3.16-rc5-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "A few more fixes for ftrace infrastructure.

  I was cleaning out my INBOX and found two fixes from zhangwei from a
  year ago that were lost in my mail.  These fix an inconsistency
  between trace_puts() and the way trace_printk() works.  The reason
  this is important to fix is because when trace_printk() doesn't have
  any arguments, it turns into a trace_puts().  Not being able to enable
  a stack trace against trace_printk() because it does not have any
  arguments is quite confusing.  Also, the fix is rather trivial and low
  risk.

  While porting some changes to PowerPC I discovered that it still has
  the function graph tracer filter bug that if you also enable stack
  tracing the function graph tracer filter is ignored.  I fixed that up.

  Finally, Martin Lau, fixed a bug that would cause readers of the
  ftrace ring buffer to block forever even though it was suppose to be
  NONBLOCK"

This also includes the fix from an earlier pull request:

 "Oleg Nesterov fixed a memory leak that happens if a user creates a
  tracing instance, sets up a filter in an event, and then removes that
  instance.  The filter allocates memory that is never freed when the
  instance is destroyed"

* tag 'trace-fixes-v3.16-rc5-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Fix polling on trace_pipe
  tracing: Add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs
  tracing: Fix graph tracer with stack tracer on other archs
  tracing: Add ftrace_trace_stack into __trace_puts/__trace_bputs
  tracing: instance_rmdir() leaks ftrace_event_file->filter
2014-07-17 07:57:33 -10:00
Steven Rostedt (Red Hat) 1b2f121c14 ftrace-graph: Remove dependency of ftrace_stop() from ftrace_graph_stop()
ftrace_stop() is going away as it disables parts of function tracing
that affects users that should not be affected. But ftrace_graph_stop()
is built on ftrace_stop(). Here's another example of killing all of
function tracing because something went wrong with function graph
tracing.

Instead of disabling all users of function tracing on function graph
error, disable only function graph tracing.

A new function is created called ftrace_graph_is_dead(). This is called
in strategic paths to prevent function graph from doing more harm and
allowing at least a warning to be printed before the system crashes.

NOTE: ftrace_stop() is still used until all the archs are converted over
to use ftrace_graph_is_dead(). After that, ftrace_stop() will be removed.

Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-17 09:45:07 -04:00
Steven Rostedt (Red Hat) 2b014666a1 PM / Sleep: Remove ftrace_stop/start() from suspend and hibernate
ftrace_stop() and ftrace_start() were added to the suspend and hibernate
process because there was some function within the work flow that caused
the system to reboot if it was traced. This function has recently been
found (restore_processor_state()). Now there's no reason to disable
function tracing while we are going into suspend or hibernate, which means
that being able to trace this will help tremendously in debugging any
issues with suspend or hibernate.

This also means that the ftrace_stop/start() functions can be removed
and simplify the function tracing code a bit.

Link: http://lkml.kernel.org/r/1518201.VD9cU33jRU@vostro.rjw.lan

Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-17 09:45:06 -04:00
Boris BREZILLON a5152c8a12 genirq: generic chip: Export irq_map_generic_chip function
Export the generic irq map function in order to provide irq_domain ops with
generic mapping and specific of xlate function (needed by the new atmel
AIC driver).

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1405012462-766-2-git-send-email-boris.brezillon@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-07-17 13:30:00 +00:00
Davidlohr Bueso 3a6bfbc91d arch, locking: Ciao arch_mutex_cpu_relax()
The arch_mutex_cpu_relax() function, introduced by 34b133f, is
hacky and ugly. It was added a few years ago to address the fact
that common cpu_relax() calls include yielding on s390, and thus
impact the optimistic spinning functionality of mutexes. Nowadays
we use this function well beyond mutexes: rwsem, qrwlock, mcs and
lockref. Since the macro that defines the call is in the mutex header,
any users must include mutex.h and the naming is misleading as well.

This patch (i) renames the call to cpu_relax_lowlatency  ("relax, but
only if you can do it with very low latency") and (ii) defines it in
each arch's asm/processor.h local header, just like for regular cpu_relax
functions. On all archs, except s390, cpu_relax_lowlatency is simply cpu_relax,
and thus we can take it out of mutex.h. While this can seem redundant,
I believe it is a good choice as it allows us to move out arch specific
logic from generic locking primitives and enables future(?) archs to
transparently define it, similarly to System Z.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bharat Bhushan <r65777@freescale.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Joseph Myers <joseph@codesourcery.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Stratos Karafotis <stratosk@semaphore.gr>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: adi-buildroot-devel@lists.sourceforge.net
Cc: linux390@de.ibm.com
Cc: linux-alpha@vger.kernel.org
Cc: linux-am33-list@redhat.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-cris-kernel@axis.com
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux@lists.openrisc.net
Cc: linux-m32r-ja@ml.linux-m32r.org
Cc: linux-m32r@ml.linux-m32r.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-metag@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1404079773.2619.4.camel@buesod1.americas.hpqcorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-17 12:32:47 +02:00
Andreas Gruenbacher acf5937726 locking/lockdep: Only ask for /proc/lock_stat output when available
When lockdep turns itself off, the following message is logged:

  Please attach the output of /proc/lock_stat to the bug report

Omit this message when CONFIG_LOCK_STAT is off, and /proc/lock_stat
doesn't exist.

Signed-off-by: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1405451452-3824-1-git-send-email-andreas.gruenbacher@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-17 11:48:15 +02:00
Ingo Molnar b5e4111f02 Merge branch 'locking/urgent' into locking/core, before applying larger changes and to refresh the branch with fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-17 11:45:29 +02:00
Ingo Molnar 01c9db8271 Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

  * Update RCU documentation.

  * Miscellaneous fixes.

  * Maintainership changes.

  * Torture-test updates.

  * Callback-offloading changes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-17 11:34:01 +02:00
Linus Torvalds d14aef3872 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Tooling fixes and an Intel PMU driver fixlet"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Do not allow optimized switch for non-cloned events
  perf/x86/intel: ignore CondChgd bit to avoid false NMI handling
  perf symbols: Get kernel start address by symbol name
  perf tools: Fix segfault in cumulative.callchain report
2014-07-16 10:10:27 -10:00
Thomas Gleixner afdb094380 Linux 3.16-rc5
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Merge tag 'v3.16-rc5' into timers/core

Reason: Bring in upstream modifications, so the pending changes which
depend on them can be queued.
2014-07-16 21:57:38 +02:00
Oleg Nesterov 6355d54438 tracing: Kill "filter_string" arg of replace_preds()
Cosmetic, but replace_preds() doesn't need/use "char *filter_string".
Remove it to microsimplify the code.

Link: http://lkml.kernel.org/p/20140715184832.GA20519@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 14:58:53 -04:00
Oleg Nesterov bb9ef1cb7d tracing: Change apply_subsystem_event_filter() paths to check file->system == dir
filter_free_subsystem_preds(), filter_free_subsystem_filters() and
replace_system_preds() can simply check file->system->subsystem and
avoid strcmp(call->class->system).

Better yet, we can pass "struct ftrace_subsystem_dir *dir" instead of
event_subsystem and just check file->system == dir.

Thanks to Namhyung Kim who pointed out that replace_system_preds() can
be changed too.

Link: http://lkml.kernel.org/p/20140715184829.GA20516@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 14:33:35 -04:00
Oleg Nesterov ede392a750 tracing/uprobes: Kill the dead TRACE_EVENT_FL_USE_CALL_FILTER logic
alloc_trace_uprobe() sets TRACE_EVENT_FL_USE_CALL_FILTER for unknown
reason and this is simply wrong. Fortunately this has no effect because
register_uprobe_event() clears call->flags after that.

Kill both. This trace_uprobe was kzalloc'ed and we rely on this fact
anyway.

Link: http://lkml.kernel.org/p/20140715184824.GA20505@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 14:25:19 -04:00
Oleg Nesterov b5d09db5ac tracing: Kill call_filter_disable()
It seems that the only purpose of call_filter_disable() is to
make filter_disable() less clear and symmetrical, remove it.

Link: http://lkml.kernel.org/p/20140715184821.GA20498@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 14:23:12 -04:00
Oleg Nesterov 57375747b6 tracing: Kill destroy_call_preds()
Remove destroy_call_preds(). Its only caller, __trace_remove_event_call(),
can use free_event_filter() and nullify ->filter by hand.

Perhaps we could keep this trivial helper although imo it is pointless, but
then it should be static in trace_events.c.

Link: http://lkml.kernel.org/p/20140715184816.GA20495@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 14:22:32 -04:00
Oleg Nesterov 3e5454d656 tracing: Kill destroy_preds() and destroy_file_preds()
destroy_preds() makes no sense.

The only caller, event_remove(), actually wants destroy_file_preds().
__trace_remove_event_call() does destroy_call_preds() which takes care
of call->filter.

And after the previous change we can simply remove destroy_preds() from
event_remove(), we are going to call remove_event_from_tracers() which
in turn calls remove_event_file_dir()->free_event_filter().

Link: http://lkml.kernel.org/p/20140715184813.GA20488@redhat.com

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 14:19:55 -04:00
Paul E. McKenney 187497fa5e rcu: Allow for NULL tick_nohz_full_mask when nohz_full= missing
If there isn't a nohz_full= kernel parameter specified, then
tick_nohz_full_mask can legitimately be NULL.  This can cause
problems when RCU's boot code tries to cpumask_or() this value into
rcu_nocb_mask.  In addition, if NO_HZ_FULL_ALL=y, there is no point
in doing the cpumask_or() in the first place because this will cause
RCU_NOCB_CPU_ALL=y, which in turn will have all bits already set in
rcu_nocb_mask.

This commit therefore avoids the cpumask_or() if NO_HZ_FULL_ALL=y
and checks for !tick_nohz_full_running otherwise, this latter check
catching cases when there was no nohz_full= kernel parameter specified.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-07-16 10:44:46 -07:00
Steven Rostedt (Red Hat) 646d7043ad ftrace: Allow archs to specify if they need a separate function graph trampoline
Currently if an arch supports function graph tracing, the core code will
just assign the function graph trampoline to the function graph addr that
gets called.

But as the old method for function graph tracing always calls the function
trampoline first and that calls the function graph trampoline, some
archs may have the function graph trampoline dependent on operations that
were done in the function trampoline. This causes function graph tracer
to break on those archs.

Instead of having the default be to set the function graph ftrace_ops
to the function graph trampoline, have it instead just set it to zero
which will keep it from jumping to a trampoline that is not set up
to be jumped directly too.

Link: http://lkml.kernel.org/r/53BED155.9040607@nvidia.com

Reported-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Tested-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16 11:01:24 -04:00
NeilBrown c1221321b7 sched: Allow wait_on_bit_action() functions to support a timeout
It is currently not possible for various wait_on_bit functions
to implement a timeout.

While the "action" function that is called to do the waiting
could certainly use schedule_timeout(), there is no way to carry
forward the remaining timeout after a false wake-up.
As false-wakeups a clearly possible at least due to possible
hash collisions in bit_waitqueue(), this is a real problem.

The 'action' function is currently passed a pointer to the word
containing the bit being waited on.  No current action functions
use this pointer.  So changing it to something else will be a
little noisy but will have no immediate effect.

This patch changes the 'action' function to take a pointer to
the "struct wait_bit_key", which contains a pointer to the word
containing the bit so nothing is really lost.

It also adds a 'private' field to "struct wait_bit_key", which
is initialized to zero.

An action function can now implement a timeout with something
like

static int timed_out_waiter(struct wait_bit_key *key)
{
	unsigned long waited;
	if (key->private == 0) {
		key->private = jiffies;
		if (key->private == 0)
			key->private -= 1;
	}
	waited = jiffies - key->private;
	if (waited > 10 * HZ)
		return -EAGAIN;
	schedule_timeout(waited - 10 * HZ);
	return 0;
}

If any other need for context in a waiter were found it would be
easy to use ->private for some other purpose, or even extend
"struct wait_bit_key".

My particular need is to support timeouts in nfs_release_page()
to avoid deadlocks with loopback mounted NFS.

While wait_on_bit_timeout() would be a cleaner interface, it
will not meet my need.  I need the timeout to be sensitive to
the state of the connection with the server, which could change.
 So I need to use an 'action' interface.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051604.28027.41257.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 15:10:41 +02:00
NeilBrown 743162013d sched: Remove proliferation of wait_on_bit() action functions
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().

So:
 Rename wait_on_bit and        wait_on_bit_lock to
        wait_on_bit_action and wait_on_bit_lock_action
 to make it explicit that they need an action function.

 Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
 which are *not* given an action function but implicitly use
 a standard one.
 The decision to error-out if a signal is pending is now made
 based on the 'mode' argument rather than being encoded in the action
 function.

 All instances of the old wait_on_bit and wait_on_bit_lock which
 can use the new version have been changed accordingly and their
 action functions have been discarded.
 wait_on_bit{_lock} does not return any specific error code in the
 event of a signal so the caller must check for non-zero and
 interpolate their own error code as appropriate.

The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"

The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.

A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack.  So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).

Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS.  CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 15:10:39 +02:00
Ingo Molnar d26fad5b38 Linux 3.16-rc5
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Merge tag 'v3.16-rc5' into sched/core, to refresh the branch before applying bigger tree-wide changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 15:10:07 +02:00
Davidlohr Bueso 5db6c6fefb locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER
Just like with mutexes (CONFIG_MUTEX_SPIN_ON_OWNER),
encapsulate the dependencies for rwsem optimistic spinning.
No logical changes here as it continues to depend on both
SMP and the XADD algorithm variant.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Jason Low <jason.low2@hp.com>
[ Also make it depend on ARCH_SUPPORTS_ATOMIC_RMW. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1405112406-13052-2-git-send-email-davidlohr@hp.com
Cc: aswin@hp.com
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 14:57:13 +02:00
Peter Zijlstra 4badad352a locking/mutex: Disable optimistic spinning on some architectures
The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.

There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.

Opt in for known good archs.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: stable@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 14:57:07 +02:00
Peter Zijlstra 13b9a962a2 locking/rwsem: Rename 'activity' to 'count'
There are two definitions of struct rw_semaphore, one in linux/rwsem.h
and one in linux/rwsem-spinlock.h.

For some reason they have different names for the initial field. This
makes it impossible to use C99 named initialization for
__RWSEM_INITIALIZER() -- or we have to duplicate that entire thing
along with the structure definitions.

The simpler patch is renaming the rwsem-spinlock variant to match the
regular rwsem.

This allows us to switch to C99 named initialization.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-bmrZolsbGmautmzrerog27io@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 14:56:55 +02:00
Peter Zijlstra e720fff634 sched/numa: Revert "Use effective_load() to balance NUMA loads"
Due to divergent trees, Rik find that this patch is no longer
required.

Requested-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-u6odkgkw8wz3m7orgsjfo5pi@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:23 +02:00
Jason Baron 5cd08fbfdb sched: Fix static_key race with sched_feat()
As pointed out by Andi Kleen, the usage of static keys can be racy in
sched_feat_disable() vs. sched_feat_enable(). Currently, we first check the
value of keys->enabled, and subsequently update the branch direction. This,
can be racy and can potentially leave the keys in an inconsistent state.

Take the i_mutex around these calls to resolve the race.

Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/9d7780c83db26683955cd01e6bc654ee2586e67f.1404315388.git.jbaron@akamai.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:21 +02:00
Jason Baron 6e76ea8a82 sched: Remove extra static_key*() function indirection
I think its a bit simpler without having to follow an extra layer of static
inline fuctions. No functional change just cosmetic.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: rostedt@goodmis.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/2ce52233ce200faad93b6029d90f1411cd926667.1404315388.git.jbaron@akamai.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:20 +02:00
xiaofeng.yan 1b09d29bc0 sched/rt: Fix replenish_dl_entity() comments to match the current upstream code
Signed-off-by: xiaofeng.yan <xiaofeng.yan@huawei.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1404712744-16986-1-git-send-email-xiaofeng.yan@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:20 +02:00
Kirill Tkhai 8875125efe sched: Transform resched_task() into resched_curr()
We always use resched_task() with rq->curr argument.
It's not possible to reschedule any task but rq's current.

The patch introduces resched_curr(struct rq *) to
replace all of the repeating patterns. The main aim
is cleanup, but there is a little size profit too:

  (before)
	$ size kernel/sched/built-in.o
	   text	   data	    bss	    dec	    hex	filename
	155274	  16445	   7042	 178761	  2ba49	kernel/sched/built-in.o

	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	7411490	1178376	 991232	9581098	 92322a	vmlinux

  (after)
	$ size kernel/sched/built-in.o
	   text	   data	    bss	    dec	    hex	filename
	155130	  16445	   7042	 178617	  2b9b9	kernel/sched/built-in.o

	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	7411362	1178376	 991232	9580970	 9231aa	vmlinux

	I was choosing between resched_curr() and resched_rq(),
	and the first name looks better for me.

A little lie in Documentation/trace/ftrace.txt. I have not
actually collected the tracing again. With a hope the patch
won't make execution times much worse :)

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140628200219.1778.18735.stgit@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:19 +02:00
Oleg Nesterov 466af29bf4 sched/deadline: Kill task_struct->pi_top_task
Remove task_struct->pi_top_task. The only user, rt_mutex_setprio(),
can use a local.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daeseok Youn <daeseok.youn@gmail.com>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Dempsky <mdempsky@chromium.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20140606165206.GB29465@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:38:18 +02:00
Mateusz Guzik b0ab99e773 sched: Fix possible divide by zero in avg_atom() calculation
proc_sched_show_task() does:

  if (nr_switches)
	do_div(avg_atom, nr_switches);

nr_switches is unsigned long and do_div truncates it to 32 bits, which
means it can test non-zero on e.g. x86-64 and be truncated to zero for
division.

Fix the problem by using div64_ul() instead.

As a side effect calculations of avg_atom for big nr_switches are now correct.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1402750809-31991-1-git-send-email-mguzik@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:36:07 +02:00
Jiri Olsa fbe26abe11 perf: Add vm_ops->name call for mmap event name retrieval
The following patch added another way to get mmap name: 78d683e838
("mm, fs: Add vm_ops->name as an alternative to arch_vma_name")

The vdso vma mapping already switch to this and we no longer get vdso
name via arch_vma_name function. Adding this way to the perf mmap
event name retrieval code.

Caught this via perf test:

  $ sudo ./perf test -v 7
   7: Validate PERF_RECORD_* events & perf_sample fields     :
  --- start ---

SNIP

  PERF_RECORD_MMAP for [vdso] missing!
  test child finished with 255
  ---- end ----
  Validate PERF_RECORD_* events & perf_sample fields: FAILED!

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1405353439-14211-1-git-send-email-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:31:22 +02:00
Jason Low 33ecd2083a locking/spinlocks/mcs: Micro-optimize osq_unlock()
In the unlock function of the cancellable MCS spinlock, the first
thing we do is to retrive the current CPU's osq node. However, due to
the changes made in the previous patch, in the common case where the
lock is not contended, we wouldn't need to access the current CPU's
osq node anymore.

This patch optimizes this by only retriving this CPU's osq node
after we attempt the initial cmpxchg to unlock the osq and found
that its contended.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1405358872-3732-5-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:28:06 +02:00
Jason Low 4d9d951e6b locking/spinlocks/mcs: Introduce and use init macro and function for osq locks
Currently, we initialize the osq lock by directly setting the lock's values. It
would be preferable if we use an init macro to do the initialization like we do
with other locks.

This patch introduces and uses a macro and function for initializing the osq lock.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Link: http://lkml.kernel.org/r/1405358872-3732-4-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:28:05 +02:00
Jason Low 90631822c5 locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead
The cancellable MCS spinlock is currently used to queue threads that are
doing optimistic spinning. It uses per-cpu nodes, where a thread obtaining
the lock would access and queue the local node corresponding to the CPU that
it's running on. Currently, the cancellable MCS lock is implemented by using
pointers to these nodes.

In this patch, instead of operating on pointers to the per-cpu nodes, we
store the CPU numbers in which the per-cpu nodes correspond to in atomic_t.
A similar concept is used with the qspinlock.

By operating on the CPU # of the nodes using atomic_t instead of pointers
to those nodes, this can reduce the overhead of the cancellable MCS spinlock
by 32 bits (on 64 bit systems).

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chris Mason <clm@fb.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Link: http://lkml.kernel.org/r/1405358872-3732-3-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:28:04 +02:00
Jason Low 046a619d8e locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node()
Currently, the per-cpu nodes structure for the cancellable MCS spinlock is
named "optimistic_spin_queue". However, in a follow up patch in the series
we will be introducing a new structure that serves as the new "handle" for
the lock. It would make more sense if that structure is named
"optimistic_spin_queue". Additionally, since the current use of the
"optimistic_spin_queue" structure are  "nodes", it might be better if we
rename them to "node" anyway.

This preparatory patch renames all current "optimistic_spin_queue"
to "optimistic_spin_node".

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chris Mason <clm@fb.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Link: http://lkml.kernel.org/r/1405358872-3732-2-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:28:03 +02:00
Jason Low 37e9562453 locking/rwsem: Allow conservative optimistic spinning when readers have lock
Commit 4fc828e24c ("locking/rwsem: Support optimistic spinning")
introduced a major performance regression for workloads such as
xfs_repair which mix read and write locking of the mmap_sem across
many threads. The result was xfs_repair ran 5x slower on 3.16-rc2
than on 3.15 and using 20x more system CPU time.

Perf profiles indicate in some workloads that significant time can
be spent spinning on !owner. This is because we don't set the lock
owner when readers(s) obtain the rwsem.

In this patch, we'll modify rwsem_can_spin_on_owner() such that we'll
return false if there is no lock owner. The rationale is that if we
just entered the slowpath, yet there is no lock owner, then there is
a possibility that a reader has the lock. To be conservative, we'll
avoid spinning in these situations.

This patch reduced the total run time of the xfs_repair workload from
about 4 minutes 24 seconds down to approximately 1 minute 26 seconds,
back to close to the same performance as on 3.15.

Retesting of AIM7, which were some of the workloads used to test the
original optimistic spinning code, confirmed that we still get big
performance gains with optimistic spinning, even with this additional
regression fix. Davidlohr found that while the 'custom' workload took
a performance hit of ~-14% to throughput for >300 users with this
additional patch, the overall gain with optimistic spinning is
still ~+45%. The 'disk' workload even improved by ~+15% at >1000 users.

Tested-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1404532172.2572.30.camel@j-VirtualBox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:28:02 +02:00
Peter Zijlstra 4a1c0f262f perf: Fix lockdep warning on process exit
Sasha Levin reported:

> While fuzzing with trinity inside a KVM tools guest running the latest -next
> kernel I've stumbled on the following spew:
>
> ======================================================
> [ INFO: possible circular locking dependency detected ]
> 3.15.0-next-20140613-sasha-00026-g6dd125d-dirty #654 Not tainted
> -------------------------------------------------------
> trinity-c578/9725 is trying to acquire lock:
> (&(&pool->lock)->rlock){-.-...}, at: __queue_work (kernel/workqueue.c:1346)
>
> but task is already holding lock:
> (&ctx->lock){-.....}, at: perf_event_exit_task (kernel/events/core.c:7471 kernel/events/core.c:7533)
>
> which lock already depends on the new lock.

> 1 lock held by trinity-c578/9725:
> #0: (&ctx->lock){-.....}, at: perf_event_exit_task (kernel/events/core.c:7471 kernel/events/core.c:7533)
>
>  Call Trace:
>  dump_stack (lib/dump_stack.c:52)
>  print_circular_bug (kernel/locking/lockdep.c:1216)
>  __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182)
>  lock_acquire (./arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602)
>  _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151)
>  __queue_work (kernel/workqueue.c:1346)
>  queue_work_on (kernel/workqueue.c:1424)
>  free_object (lib/debugobjects.c:209)
>  __debug_check_no_obj_freed (lib/debugobjects.c:715)
>  debug_check_no_obj_freed (lib/debugobjects.c:727)
>  kmem_cache_free (mm/slub.c:2683 mm/slub.c:2711)
>  free_task (kernel/fork.c:221)
>  __put_task_struct (kernel/fork.c:250)
>  put_ctx (include/linux/sched.h:1855 kernel/events/core.c:898)
>  perf_event_exit_task (kernel/events/core.c:907 kernel/events/core.c:7478 kernel/events/core.c:7533)
>  do_exit (kernel/exit.c:766)
>  do_group_exit (kernel/exit.c:884)
>  get_signal_to_deliver (kernel/signal.c:2347)
>  do_signal (arch/x86/kernel/signal.c:698)
>  do_notify_resume (arch/x86/kernel/signal.c:751)
>  int_signal (arch/x86/kernel/entry_64.S:600)

Urgh.. so the only way I can make that happen is through:

  perf_event_exit_task_context()
    raw_spin_lock(&child_ctx->lock);
    unclone_ctx(child_ctx)
      put_ctx(ctx->parent_ctx);
    raw_spin_unlock_irqrestore(&child_ctx->lock);

And we can avoid this by doing the change below.

I can't immediately see how this changed recently, but given that you
say it's easy to reproduce, lets fix this.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140623141242.GB19860@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:18:42 +02:00
Peter Zijlstra 1903d50cba perf: Revert ("perf: Always destroy groups on exit")
Vince reported that commit 15a2d4de0e ("perf: Always destroy groups
on exit") causes a regression with grouped events. In particular his
read_group_attached.c test fails.

  https://github.com/deater/perf_event_tests/blob/master/tests/bugs/read_group_attached.c

Because of the context switch optimization in
perf_event_context_sched_out() the 'original' event may end up in the
child process and when that exits the change in the patch in question
destroys the actual grouping.

Therefore revert that change and only destroy inherited groups.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-zedy3uktcp753q8fw8dagx7a@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 13:18:39 +02:00
Martin Lau 97b8ee8453 ring-buffer: Fix polling on trace_pipe
ring_buffer_poll_wait() should always put the poll_table to its wait_queue
even there is immediate data available.  Otherwise, the following epoll and
read sequence will eventually hang forever:

1. Put some data to make the trace_pipe ring_buffer read ready first
2. epoll_ctl(efd, EPOLL_CTL_ADD, trace_pipe_fd, ee)
3. epoll_wait()
4. read(trace_pipe_fd) till EAGAIN
5. Add some more data to the trace_pipe ring_buffer
6. epoll_wait() -> this epoll_wait() will block forever

~ During the epoll_ctl(efd, EPOLL_CTL_ADD,...) call in step 2,
  ring_buffer_poll_wait() returns immediately without adding poll_table,
  which has poll_table->_qproc pointing to ep_poll_callback(), to its
  wait_queue.
~ During the epoll_wait() call in step 3 and step 6,
  ring_buffer_poll_wait() cannot add ep_poll_callback() to its wait_queue
  because the poll_table->_qproc is NULL and it is how epoll works.
~ When there is new data available in step 6, ring_buffer does not know
  it has to call ep_poll_callback() because it is not in its wait queue.
  Hence, block forever.

Other poll implementation seems to call poll_wait() unconditionally as the very
first thing to do.  For example, tcp_poll() in tcp.c.

Link: http://lkml.kernel.org/p/20140610060637.GA14045@devbig242.prn2.facebook.com

Cc: stable@vger.kernel.org # 2.6.27
Fixes: 2a2cc8f7c4 "ftrace: allow the event pipe to be polled"
Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Martin Lau <kafai@fb.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-15 17:07:47 -04:00
zhangwei(Jovi) f0160a5a29 tracing: Add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs
The TRACE_ITER_PRINTK check in __trace_puts/__trace_bputs is missing,
so add it, to be consistent with __trace_printk/__trace_bprintk.
Those functions are all called by the same function: trace_printk().

Link: http://lkml.kernel.org/p/51E7A7D6.8090900@huawei.com

Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-15 11:58:40 -04:00
Lai Jiangshan f7537df520 workqueue: alloc struct worker on its local node
When the create_worker() is called from non-manager, the struct worker
is allocated from the node of the caller which may be different from the
node of pool->node.

So we add a node ID argument for the alloc_worker() to ensure the
struct worker is allocated from the preferable node.

tj: @nid renamed to @node for consistency.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-15 11:11:20 -04:00
Steven Rostedt (Red Hat) 5f8bf2d263 tracing: Fix graph tracer with stack tracer on other archs
Running my ftrace tests on PowerPC, it failed the test that checks
if function_graph tracer is affected by the stack tracer. It was.
Looking into this, I found that the update_function_graph_func()
must be called even if the trampoline function is not changed.
This is because archs like PowerPC do not support ftrace_ops being
passed by assembly and instead uses a helper function (what the
trampoline function points to). Since this function is not changed
even when multiple ftrace_ops are added to the code, the test that
falls out before calling update_function_graph_func() will miss that
the update must still be done.

Call update_function_graph_function() for all calls to
update_ftrace_function()

Cc: stable@vger.kernel.org # 3.3+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-15 11:10:25 -04:00
Tejun Heo 5de4fa13c4 cgroup: initialize cgrp_dfl_root_inhibit_ss_mask from !->dfl_files test
cgrp_dfl_root_inhibit_ss_mask determines which subsystems are not
supported on the default hierarchy and is currently initialized
statically and just includes the debug subsystem.  Now that there's
cgroup_subsys->dfl_files, we can easily tell which subsystems support
the default hierarchy or not.

Let's initialize cgrp_dfl_root_inhibit_ss_mask by testing whether
cgroup_subsys->dfl_files is NULL.  After all, subsystems with NULL
->dfl_files aren't useable on the default hierarchy anyway.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2014-07-15 11:05:10 -04:00
Tejun Heo 05ebb6e60f cgroup: make CFTYPE_ONLY_ON_DFL and CFTYPE_NO_ internal to cgroup core
cgroup now distinguishes cftypes for the default and legacy
hierarchies more explicitly by using separate arrays and
CFTYPE_ONLY_ON_DFL and CFTYPE_INSANE should be and are used only
inside cgroup core proper.  Let's make it clear that the flags are
internal by prefixing them with double underscores.

CFTYPE_INSANE is renamed to __CFTYPE_NOT_ON_DFL for consistency.  The
two flags are also collected and assigned bits >= 16 so that they
aren't mixed with the published flags.

v2: Convert the extra ones in cgroup_exit_cftypes() which are added by
    revision to the previous patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2014-07-15 11:05:10 -04:00
Tejun Heo a8ddc8215e cgroup: distinguish the default and legacy hierarchies when handling cftypes
Until now, cftype arrays carried files for both the default and legacy
hierarchies and the files which needed to be used on only one of them
were flagged with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE.  This
gets confusing very quickly and we may end up exposing interface files
to the default hierarchy without thinking it through.

This patch makes cgroup core provide separate sets of interfaces for
cftype handling so that the cftypes for the default and legacy
hierarchies are clearly distinguished.  The previous two patches
renamed the existing ones so that they clearly indicate that they're
for the legacy hierarchies.  This patch adds the interface for the
default hierarchy and apply them selectively depending on the
hierarchy type.

* cftypes added through cgroup_subsys->dfl_cftypes and
  cgroup_add_dfl_cftypes() only show up on the default hierarchy.

* cftypes added through cgroup_subsys->legacy_cftypes and
  cgroup_add_legacy_cftypes() only show up on the legacy hierarchies.

* cgroup_subsys->dfl_cftypes and ->legacy_cftypes can point to the
  same array for the cases where the interface files are identical on
  both types of hierarchies.

* This makes all the existing subsystem interface files legacy-only by
  default and all subsystems will have no interface file created when
  enabled on the default hierarchy.  Each subsystem should explicitly
  review and compose the interface for the default hierarchy.

* A boot param "cgroup__DEVEL__legacy_files_on_dfl" is added which
  makes subsystems which haven't decided the interface files for the
  default hierarchy to present the legacy files on the default
  hierarchy so that its behavior on the default hierarchy can be
  tested.  As the awkward name suggests, this is for development only.

* memcg's CFTYPE_INSANE on "use_hierarchy" is noop now as the whole
  array isn't used on the default hierarchy.  The flag is removed.

v2: Updated documentation for cgroup__DEVEL__legacy_files_on_dfl.

v3: Clear CFTYPE_ONLY_ON_DFL and CFTYPE_INSANE when cfts are removed
    as suggested by Li.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2014-07-15 11:05:10 -04:00