linux/arch/x86/include/asm/qrwlock.h
Waiman Long bd01ec1a13 x86, locking/rwlocks: Enable qrwlocks on x86
Make x86 use the fair rwlock_t.

Implement the custom queue_write_unlock() for best performance.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
[peterz: near complete rewrite]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org
Cc: x86@kernel.org
Link: http://lkml.kernel.org/n/tip-r1xuzmdysvuhl3h86n5fbxi7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-06 07:58:29 +02:00

18 lines
411 B
C

#ifndef _ASM_X86_QRWLOCK_H
#define _ASM_X86_QRWLOCK_H
#include <asm-generic/qrwlock_types.h>
#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
#define queue_write_unlock queue_write_unlock
static inline void queue_write_unlock(struct qrwlock *lock)
{
barrier();
ACCESS_ONCE(*(u8 *)&lock->cnts) = 0;
}
#endif
#include <asm-generic/qrwlock.h>
#endif /* _ASM_X86_QRWLOCK_H */