* [PATCH] lockref: Relax in cmpxchg loop
@ 2013-09-03 21:49 Luck, Tony
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From: Luck, Tony @ 2013-09-03 21:49 UTC (permalink / raw)
To: Linus Torvalds, linux-kernel
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>
---
diff --git a/lib/lockref.c b/lib/lockref.c
index 7819c2d..9d76f40 100644
--- 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)
--
1.8.1.4
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2013-09-03 21:49 [PATCH] lockref: Relax in cmpxchg loop Luck, Tony
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