From: Peter Zijlstra <peterz@infradead.org>
To: "Chen, Dennis (SRDC SW)" <Dennis1.Chen@amd.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
"paulmck@linux.vnet.ibm.com" <paulmck@linux.vnet.ibm.com>,
Paul Mackerras <paulus@samba.org>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: A quick view of the performance benchmark for semaphore-like and mutex
Date: Tue, 17 Apr 2012 12:12:49 +0200 [thread overview]
Message-ID: <1334657569.28150.81.camel@twins> (raw)
In-Reply-To: <491D6B4EAD0A714894D8AD22F4BDE043B15DCF@SCYBEXDAG03.amd.com>
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
anymore.
next prev parent reply other threads:[~2012-04-17 10:13 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-17 9:36 A quick view of the performance benchmark for semaphore-like and mutex Chen, Dennis (SRDC SW)
2012-04-17 10:09 ` Peter Zijlstra
2012-04-17 10:12 ` Peter Zijlstra [this message]
2012-04-17 11:52 ` Chen, Dennis (SRDC SW)
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