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authorJiri Olsa <jolsa@redhat.com>2009-07-08 12:10:31 +0000
committerDavid S. Miller <davem@davemloft.net>2009-07-09 17:06:58 -0700
commitad46276952f1af34cd91d46d49ba13d347d56367 (patch)
tree55cf35156794ab34d8a607c25fd044c37231f9e4 /include/linux/spinlock.h
parenta57de0b4336e48db2811a2030bb68dba8dd09d88 (diff)
memory barrier: adding smp_mb__after_lock
Adding smp_mb__after_lock define to be used as a smp_mb call after a lock. Making it nop for x86, since {read|write|spin}_lock() on x86 are full memory barriers. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/spinlock.h')
-rw-r--r--include/linux/spinlock.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 252b245cfcf4..4be57ab03478 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -132,6 +132,11 @@ do { \
#endif /*__raw_spin_is_contended*/
#endif
+/* The lock does not imply full memory barrier. */
+#ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
+static inline void smp_mb__after_lock(void) { smp_mb(); }
+#endif
+
/**
* spin_unlock_wait - wait until the spinlock gets unlocked
* @lock: the spinlock in question.