linux/kernel/locking
Waiman Long aa68744f80 locking/qspinlock: Avoid redundant read of next pointer
With optimistic prefetch of the next node cacheline, the next pointer
may have been properly inititalized. As a result, the reading
of node->next in the contended path may be redundant. This patch
eliminates the redundant read if the next pointer value is not NULL.

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: Davidlohr Bueso <dave@stgolabs.net>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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/1447114167-47185-4-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23 10:02:00 +01:00
..
lglock.c
lockdep.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
locktorture.c
Makefile
mcs_spinlock.h
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
osq_lock.c
percpu-rwsem.c
qrwlock.c
qspinlock.c locking/qspinlock: Avoid redundant read of next pointer 2015-11-23 10:02:00 +01:00
qspinlock_paravirt.h
rtmutex-debug.c
rtmutex-debug.h rtmutex: Cleanup deadlock detector debug logic 2014-06-21 22:05:30 +02:00
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem-spinlock.c
rwsem-xadd.c
rwsem.c
rwsem.h
semaphore.c
spinlock.c
spinlock_debug.c