linux-toradex.git/include/linux, branch v3.16-rc6

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-07-19T16:27:55+00:00

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

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-07-19T16:23:27+00:00

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()

Merge tag 'pm+acpi-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2014-07-19T06:28:27+00:00

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

cpufreq: make table sentinel macros unsigned to match use

2014-07-18T00:56:38+00:00

Commit 5eeaf1f18973 (cpufreq: Fix build error on some platforms that
use cpufreq_for_each_*) moved function cpufreq_next_valid() to a public
header.  Warnings are now generated when objects including that header
are built with -Wsign-compare (as an out-of-tree module might be):

.../include/linux/cpufreq.h: In function ‘cpufreq_next_valid’:
.../include/linux/cpufreq.h:519:27: warning: comparison between signed
and unsigned integer expressions [-Wsign-compare]
  while ((*pos)->frequency != CPUFREQ_TABLE_END)
                           ^
.../include/linux/cpufreq.h:520:25: warning: comparison between signed
and unsigned integer expressions [-Wsign-compare]
   if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
                         ^

Constants CPUFREQ_ENTRY_INVALID and CPUFREQ_TABLE_END are signed, but
are used with unsigned member 'frequency' of cpufreq_frequency_table.
Update the macro definitions to be explicitly unsigned to match their
use.

This also corrects potentially wrong behavior of clk_rate_table_iter()
if unsigned long is wider than usigned int.

Fixes: 5eeaf1f18973 (cpufreq: Fix build error on some platforms that use cpufreq_for_each_*)
Signed-off-by: Brian W Hart 
Reviewed-by: Simon Horman 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-07-16T20:11:02+00:00

Pull scheduler fixes from Ingo Molnar:
 "A cpufreq lockup fix and a compiler warning fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix compiler warnings
  x86, tsc: Fix cpufreq lockup

locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER

2014-07-16T12:57:13+00:00

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 
Acked-by: Jason Low 
[ Also make it depend on ARCH_SUPPORTS_ATOMIC_RMW. ]
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1405112406-13052-2-git-send-email-davidlohr@hp.com
Cc: aswin@hp.com
Cc: Chris Mason 
Cc: Davidlohr Bueso 
Cc: Josef Bacik 
Cc: Linus Torvalds 
Cc: Waiman Long 
Signed-off-by: Ingo Molnar 

Signed-off-by: Ingo Molnar

locking/rwsem: Reduce the size of struct rw_semaphore

2014-07-16T12:57:03+00:00

Recent optimistic spinning additions to rwsem provide significant performance
benefits on many workloads on large machines. The cost of it was increasing
the size of the rwsem structure by up to 128 bits.

However, now that the previous patches in this series bring the overhead of
struct optimistic_spin_queue to 32 bits, this patch reorders some fields in
struct rw_semaphore such that we can reduce the overhead of the rwsem structure
by 64 bits (on 64 bit systems).

The extra overhead required for rwsem optimistic spinning would now be up
to 8 additional bytes instead of up to 16 bytes. Additionally, the size of
rwsem would now be more in line with mutexes.

Signed-off-by: Jason Low 
Signed-off-by: Peter Zijlstra 
Cc: Scott Norton 
Cc: "Paul E. McKenney" 
Cc: Dave Chinner 
Cc: Waiman Long 
Cc: Davidlohr Bueso 
Cc: Rik van Riel 
Cc: Andrew Morton 
Cc: "H. Peter Anvin" 
Cc: Steven Rostedt 
Cc: Tim Chen 
Cc: Konrad Rzeszutek Wilk 
Cc: Aswin Chandramouleeswaran 
Cc: Linus Torvalds 
Cc: Chris Mason 
Cc: Josef Bacik 
Link: http://lkml.kernel.org/r/1405358872-3732-6-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar

locking/rwsem: Rename 'activity' to 'count'

2014-07-16T12:56:55+00:00

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 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/n/tip-bmrZolsbGmautmzrerog27io@git.kernel.org
Signed-off-by: Ingo Molnar

locking/spinlocks/mcs: Introduce and use init macro and function for osq locks

2014-07-16T11:28:05+00:00

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 
Signed-off-by: Peter Zijlstra 
Cc: Scott Norton 
Cc: "Paul E. McKenney" 
Cc: Dave Chinner 
Cc: Waiman Long 
Cc: Davidlohr Bueso 
Cc: Rik van Riel 
Cc: Andrew Morton 
Cc: "H. Peter Anvin" 
Cc: Steven Rostedt 
Cc: Tim Chen 
Cc: Konrad Rzeszutek Wilk 
Cc: Aswin Chandramouleeswaran 
Cc: Linus Torvalds 
Cc: Chris Mason 
Cc: Josef Bacik 
Link: http://lkml.kernel.org/r/1405358872-3732-4-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar

locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead

2014-07-16T11:28:04+00:00

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 
Signed-off-by: Peter Zijlstra 
Cc: Scott Norton 
Cc: "Paul E. McKenney" 
Cc: Dave Chinner 
Cc: Waiman Long 
Cc: Davidlohr Bueso 
Cc: Rik van Riel 
Cc: Andrew Morton 
Cc: "H. Peter Anvin" 
Cc: Steven Rostedt 
Cc: Tim Chen 
Cc: Konrad Rzeszutek Wilk 
Cc: Aswin Chandramouleeswaran 
Cc: Linus Torvalds 
Cc: Chris Mason 
Cc: Heiko Carstens 
Cc: Josef Bacik 
Link: http://lkml.kernel.org/r/1405358872-3732-3-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar