Re: A quick view of the performance benchmark for semaphore-likeand mutex

From: Peter Zijlstra
Date: Tue Apr 17 2012 - 06:13:06 EST

On Tue, 2012-04-17 at 09:36 +0000, Chen, Dennis (SRDC SW) wrote:
> Interesting!! Semaphore-like is almost 8s slower than mutex... Also, the Events sycles of perf
> reported is different

I suspect that if you were to use actual semaphores it would be even
worse, the semaphore implementation doesn't do lock-stealing nor does it
have fancy assembly fast paths.

In fact, I don't know why you even bother with sems, they're a
deprecated serialization primitive that really shouldn't be used
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