linux/kernel/locking
Waiman Long 08be8f63c4 locking/pvstat: Separate wait_again and spurious wakeup stats
Currently there are overlap in the pvqspinlock wait_again and
spurious_wakeup stat counters. Because of lock stealing, it is
no longer possible to accurately determine if spurious wakeup has
happened in the queue head.  As they track both the queue node and
queue head status, it is also hard to tell how many of those comes
from the queue head and how many from the queue node.

This patch changes the accounting rules so that spurious wakeup is
only tracked in the queue node. The wait_again count, however, is
only tracked in the queue head when the vCPU failed to acquire the
lock after a vCPU kick. This should give a much better indication of
the wait-kick dynamics in the queue node and the queue head.

Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1464713631-1066-2-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10 14:16:02 +02:00
..
lglock.c sched/stop_machine: Fix deadlock between multiple stop_two_cpus() 2015-06-19 10:03:12 +02:00
lockdep_internals.h lockdep: Increase static allocations 2014-04-18 14:20:50 +02:00
lockdep_proc.c lockdep: Fix lock_chain::base size 2016-04-23 13:53:03 +02:00
lockdep_states.h
lockdep.c locking/lockdep: Use __jhash_mix() for iterate_chain_key() 2016-06-08 14:22:00 +02:00
locktorture.c lcoking/locktorture: Simplify the torture_runnable computation 2016-04-28 10:57:51 +02:00
Makefile kernel: add kcov code coverage 2016-03-22 15:36:02 -07:00
mcs_spinlock.h locking/mcs: Fix mcs_spin_lock() ordering 2016-02-29 10:02:41 +01:00
mutex-debug.c locking: avoid passing around 'thread_info' in mutex debugging code 2016-06-23 12:11:17 -07:00
mutex-debug.h Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-25 12:41:29 -07:00
mutex.c locking: avoid passing around 'thread_info' in mutex debugging code 2016-06-23 12:11:17 -07:00
mutex.h Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-25 12:41:29 -07:00
osq_lock.c locking/osq: Fix ordering of node initialisation in osq_lock 2015-12-17 11:40:29 -08:00
percpu-rwsem.c ext4: fix races between changing inode journal mode and ext4_writepages 2016-04-25 23:22:35 -04:00
qrwlock.c locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire() 2016-06-16 10:48:34 +02:00
qspinlock_paravirt.h locking/pvstat: Separate wait_again and spurious wakeup stats 2016-08-10 14:16:02 +02:00
qspinlock_stat.h locking/pvstat: Separate wait_again and spurious wakeup stats 2016-08-10 14:16:02 +02:00
qspinlock.c locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec() 2016-06-27 11:37:41 +02:00
rtmutex_common.h rtmutex: Delete scriptable tester 2015-07-20 11:45:45 +02:00
rtmutex-debug.c rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rtmutex-debug.h rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rtmutex.c locking/rtmutex: Only warn once on a trylock from bad context 2016-06-08 14:22:00 +02:00
rtmutex.h rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rwsem-spinlock.c locking/rwsem: Introduce basis for down_write_killable() 2016-04-13 10:42:20 +02:00
rwsem-xadd.c locking/atomic, arch/rwsem: Employ atomic_long_fetch_add() 2016-06-16 10:48:35 +02:00
rwsem.c locking/rwsem: Add reader-owned state to the owner field 2016-06-08 15:16:59 +02:00
rwsem.h locking/rwsem: Protect all writes to owner by WRITE_ONCE() 2016-06-08 15:16:59 +02:00
semaphore.c locking/semaphore: Resolve some shadow warnings 2014-09-04 07:17:24 +02:00
spinlock_debug.c locking: Move the spinlock code to kernel/locking/ 2013-11-06 07:55:21 +01:00
spinlock.c spinlock: Add spin_lock_bh_nested() 2015-01-03 14:32:57 -05:00