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| author | Waiman Long <Waiman.Long@hp.com> | 2014-02-03 13:18:57 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-06-06 07:58:29 +0200 |
| commit | bd01ec1a13f9a327950c8e3080096446c7804753 (patch) | |
| tree | 5af212f946ee023fdbadc9b14ff9e2a1431a0c72 /arch/x86/include/asm/spinlock.h | |
| parent | 70af2f8a4f48d6cebdf92d533d3aef37853ce6de (diff) | |
| download | linux-0-day-bd01ec1a13f9a327950c8e3080096446c7804753.tar.gz linux-0-day-bd01ec1a13f9a327950c8e3080096446c7804753.tar.xz | |
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>
Diffstat (limited to 'arch/x86/include/asm/spinlock.h')
| -rw-r--r-- | arch/x86/include/asm/spinlock.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index 0f62f5482d91e..54f1c8068c023 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -187,6 +187,7 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) cpu_relax(); } +#ifndef CONFIG_QUEUE_RWLOCK /* * Read-write spinlocks, allowing multiple readers * but only one writer. @@ -269,6 +270,9 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) asm volatile(LOCK_PREFIX WRITE_LOCK_ADD(%1) "%0" : "+m" (rw->write) : "i" (RW_LOCK_BIAS) : "memory"); } +#else +#include <asm/qrwlock.h> +#endif /* CONFIG_QUEUE_RWLOCK */ #define arch_read_lock_flags(lock, flags) arch_read_lock(lock) #define arch_write_lock_flags(lock, flags) arch_write_lock(lock) |