[GIT PULL] locking changes for v5.5

[Ingo Molnar]

Linus,

Please pull the latest locking-core-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-core-for-linus

   # HEAD: 500543c53a54134ced386aed85cd93cf1363f981 lkdtm: Remove references to CONFIG_REFCOUNT_FULL

The main changes in this cycle were:

 - A comprehensive rewrite of the robust/PI futex code's exit handling to 
   fix various exit races. (Thomas Gleixner et al)

 - Rework the generic REFCOUNT_FULL implementation using atomic_fetch_* 
   operations so that the performance impact of the cmpxchg() loops is 
   mitigated for common refcount operations.

   With these performance improvements the generic implementation of 
   refcount_t should be good enough for everybody - and this got 
   confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and 
   REFCOUNT_FULL entirely, leaving the generic implementation enabled 
   unconditionally. (Will Deacon)

 - Other misc changes, fixes, cleanups.

 Thanks,

	Ingo

------------------>
Dan Carpenter (1):
      locking/lockdep: Update the comment for __lock_release()

Davidlohr Bueso (2):
      futex: Drop leftover wake_q_add() comment
      locking/mutex: Complain upon mutex API misuse in IRQ contexts

Qian Cai (1):
      locking/lockdep: Remove unused @nested argument from lock_release()

Thomas Gleixner (11):
      futex: Move futex exit handling into futex code
      futex: Replace PF_EXITPIDONE with a state
      exit/exec: Seperate mm_release()
      futex: Split futex_mm_release() for exit/exec
      futex: Set task::futex_state to DEAD right after handling futex exit
      futex: Mark the begin of futex exit explicitly
      futex: Sanitize exit state handling
      futex: Provide state handling for exec() as well
      futex: Add mutex around futex exit
      futex: Provide distinct return value when owner is exiting
      futex: Prevent exit livelock

Waiman Long (1):
      lib/smp_processor_id: Don't use cpumask_equal()

Will Deacon (10):
      locking/refcount: Define constants for saturation and max refcount values
      locking/refcount: Ensure integer operands are treated as signed
      locking/refcount: Remove unused refcount_*_checked() variants
      locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header
      locking/refcount: Improve performance of generic REFCOUNT_FULL code
      locking/refcount: Move saturation warnings out of line
      locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
      locking/refcount: Consolidate implementations of refcount_t
      locking/refcount: Remove unused 'refcount_error_report()' function
      lkdtm: Remove references to CONFIG_REFCOUNT_FULL

Yang Tao (1):
      futex: Prevent robust futex exit race


 arch/Kconfig                                  |  21 --
 arch/arm/Kconfig                              |   1 -
 arch/arm64/Kconfig                            |   1 -
 arch/s390/configs/debug_defconfig             |   1 -
 arch/x86/Kconfig                              |   1 -
 arch/x86/include/asm/asm.h                    |   6 -
 arch/x86/include/asm/refcount.h               | 126 ----------
 arch/x86/mm/extable.c                         |  49 ----
 drivers/gpu/drm/drm_connector.c               |   2 +-
 drivers/gpu/drm/i915/Kconfig.debug            |   1 -
 drivers/gpu/drm/i915/gem/i915_gem_shrinker.c  |   6 +-
 drivers/gpu/drm/i915/gt/intel_engine_pm.c     |   2 +-
 drivers/gpu/drm/i915/i915_request.c           |   2 +-
 drivers/misc/lkdtm/refcount.c                 |  11 +-
 drivers/tty/tty_ldsem.c                       |   8 +-
 fs/dcache.c                                   |   2 +-
 fs/exec.c                                     |   2 +-
 fs/jbd2/transaction.c                         |   4 +-
 fs/kernfs/dir.c                               |   4 +-
 fs/ocfs2/dlmglue.c                            |   2 +-
 include/linux/compat.h                        |   2 -
 include/linux/futex.h                         |  40 +++-
 include/linux/jbd2.h                          |   2 +-
 include/linux/kernel.h                        |   7 -
 include/linux/lockdep.h                       |  21 +-
 include/linux/percpu-rwsem.h                  |   4 +-
 include/linux/rcupdate.h                      |   2 +-
 include/linux/refcount.h                      | 269 +++++++++++++++++----
 include/linux/rwlock_api_smp.h                |  16 +-
 include/linux/sched.h                         |   3 +-
 include/linux/sched/mm.h                      |   6 +-
 include/linux/seqlock.h                       |   4 +-
 include/linux/spinlock_api_smp.h              |   8 +-
 include/linux/ww_mutex.h                      |   2 +-
 include/net/sock.h                            |   2 +-
 kernel/bpf/stackmap.c                         |   2 +-
 kernel/cpu.c                                  |   2 +-
 kernel/exit.c                                 |  30 +--
 kernel/fork.c                                 |  40 ++--
 kernel/futex.c                                | 326 ++++++++++++++++++++++----
 kernel/locking/lockdep.c                      |   7 +-
 kernel/locking/mutex.c                        |   8 +-
 kernel/locking/rtmutex.c                      |   6 +-
 kernel/locking/rwsem.c                        |  10 +-
 kernel/panic.c                                |  11 -
 kernel/printk/printk.c                        |  10 +-
 kernel/sched/core.c                           |   2 +-
 lib/locking-selftest.c                        |  24 +-
 lib/refcount.c                                | 255 +++-----------------
 lib/smp_processor_id.c                        |   2 +-
 mm/memcontrol.c                               |   2 +-
 net/core/sock.c                               |   2 +-
 tools/lib/lockdep/include/liblockdep/common.h |   3 +-
 tools/lib/lockdep/include/liblockdep/mutex.h  |   2 +-
 tools/lib/lockdep/include/liblockdep/rwlock.h |   2 +-
 tools/lib/lockdep/preload.c                   |  16 +-
 56 files changed, 686 insertions(+), 716 deletions(-)
 delete mode 100644 arch/x86/include/asm/refcount.h