lockref: Relax in cmpxchg loop

While we are likley to succeed and break out of this loop, it isn't guaranteed. We should be power and thread friendly if we do have to go around for a second (or third, or more) attempt. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DX37 · Sep 3, 2013 · d472d9d · d472d9d
1 parent 2f01ea9
commit d472d9d
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/lib/lockref.c b/lib/lockref.c
@@ -19,6 +19,7 @@
 		if (likely(old.lock_count == prev.lock_count)) {		\
 			SUCCESS;						\
 		}								\
+		cpu_relax();							\
 	}									\
 } while (0)