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

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

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

Pull RCU fixes from Thomas Gleixner:
 "Two RCU patches:
   - Address a serious performance regression on open/close caused by
     commit ac1bea85781e ("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()

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

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

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

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>

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>

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>