From: Ingo Molnar <mingo@elte.hu>
To: Jie Chen <chen@jlab.org>
Cc: linux-kernel@vger.kernel.org, Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: Possible bug from kernel 2.6.22 and above, 2.6.24-rc4
Date: Tue, 11 Dec 2007 22:23:52 +0100 [thread overview]
Message-ID: <20071211212352.GF6902@elte.hu> (raw)
In-Reply-To: <475EBD30.1010506@jlab.org>
* Jie Chen <chen@jlab.org> wrote:
> The following is pthread_sync output for 2.6.21.7-cfs-v24 #1 SMP
> kernel.
> 2 threads:
> PARALLEL time = 11.106580 microseconds +/- 0.002460
> PARALLEL overhead = 0.617590 microseconds +/- 0.003409
> Output for Kernel 2.6.24-rc4 #1 SMP
> PARALLEL time = 19.668450 microseconds +/- 0.015782
> PARALLEL overhead = 9.157945 microseconds +/- 0.018217
ok, so the problem is that this PARALLEL time has an additional +9 usecs
overhead, right? I dont see this myself on a Core2 CPU:
PARALLEL time = 10.446933 microseconds +/- 0.078849
PARALLEL overhead = 0.751732 microseconds +/- 0.177446
Ingo
next prev parent reply other threads:[~2007-12-11 21:24 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-21 20:34 Possible bug from kernel 2.6.22 and above Jie Chen
2007-11-21 22:14 ` Eric Dumazet
2007-11-22 1:52 ` Jie Chen
2007-11-22 2:32 ` Simon Holm Thøgersen
2007-11-22 2:58 ` Jie Chen
2007-11-22 20:19 ` Matt Mackall
2007-12-04 13:17 ` Possible bug from kernel 2.6.22 and above, 2.6.24-rc4 Ingo Molnar
2007-12-04 15:41 ` Jie Chen
2007-12-05 15:29 ` Jie Chen
2007-12-05 15:40 ` Ingo Molnar
2007-12-05 16:16 ` Eric Dumazet
2007-12-05 16:25 ` Ingo Molnar
2007-12-05 16:29 ` Eric Dumazet
2007-12-05 16:22 ` Jie Chen
2007-12-05 16:47 ` Ingo Molnar
2007-12-05 17:47 ` Jie Chen
2007-12-05 20:03 ` Ingo Molnar
2007-12-05 20:23 ` Jie Chen
2007-12-05 20:46 ` Ingo Molnar
2007-12-05 20:52 ` Jie Chen
2007-12-05 21:02 ` Ingo Molnar
2007-12-05 22:16 ` Jie Chen
2007-12-06 10:43 ` Ingo Molnar
2007-12-06 16:29 ` Jie Chen
2007-12-10 10:59 ` Ingo Molnar
2007-12-10 20:04 ` Jie Chen
2007-12-11 10:51 ` Ingo Molnar
2007-12-11 15:28 ` Jie Chen
2007-12-11 15:52 ` Ingo Molnar
2007-12-11 16:39 ` Jie Chen
2007-12-11 21:23 ` Ingo Molnar [this message]
2007-12-11 22:11 ` Jie Chen
2007-12-12 12:49 ` Peter Zijlstra
2007-12-05 20:36 ` Possible bug from kernel 2.6.22 and above Peter Zijlstra
2007-12-05 20:53 ` Jie Chen
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