From: "David Schwartz" <davids@webmaster.com>
To: <CFRIESEN@nortel.com>
Cc: "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>
Subject: RE: CFS: some bad numbers with Java/database threading [FIXED]
Date: Wed, 19 Sep 2007 15:56:32 -0700 [thread overview]
Message-ID: <MDEHLPKNGKAHNMBLJOLKEELFGOAC.davids@webmaster.com> (raw)
In-Reply-To: <46F17D03.9090801@nortel.com>
> David Schwartz wrote:
> > Nonsense. The task is always ready-to-run. There is no reason
> > its CPU should
> > be low. This bug report is based on a misunderstanding of what yielding
> > means.
> The yielding task has given up the cpu. The other task should get to
> run for a timeslice (or whatever the equivalent is in CFS) until the
> yielding task again "becomes head of the thread list".
Are you sure this isn't happening? I'll run some tests on my SMP system
running CFS. But I'll bet the context switch rate is quite rapid.
Honestly, I can't imagine what else could be happening here. Does CFS spin
in a loop doing nothing when you call sched_yield even though another task
is ready-to-run? That seems kind of bizarre. Is sched_yield acting as a
no-op?
DS
next prev parent reply other threads:[~2007-09-19 22:57 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-12 23:10 CFS: some bad numbers with Java/database threading Antoine Martin
2007-09-13 7:18 ` David Schwartz
2007-09-12 23:33 ` Nick Piggin
2007-09-13 19:02 ` Antoine Martin
2007-09-13 21:47 ` David Schwartz
2007-09-13 11:24 ` CFS: " Ingo Molnar
2007-09-14 8:32 ` Ingo Molnar
2007-09-14 10:06 ` Satyam Sharma
2007-09-14 15:25 ` CFS: some bad numbers with Java/database threading [FIXED] Antoine Martin
2007-09-14 15:32 ` Ingo Molnar
2007-09-18 17:00 ` Chuck Ebbert
2007-09-18 22:46 ` Ingo Molnar
2007-09-18 23:02 ` Chuck Ebbert
2007-09-19 18:45 ` David Schwartz
2007-09-19 19:48 ` Chris Friesen
2007-09-19 22:56 ` David Schwartz [this message]
2007-09-19 23:05 ` David Schwartz
2007-09-19 23:52 ` David Schwartz
2007-09-19 19:18 ` Ingo Molnar
2007-09-19 19:39 ` Linus Torvalds
2007-09-19 19:56 ` Ingo Molnar
2007-09-19 20:26 ` Ingo Molnar
2007-09-19 20:28 ` Linus Torvalds
2007-09-19 21:41 ` Ingo Molnar
2007-09-19 21:49 ` Ingo Molnar
2007-09-19 21:58 ` Peter Zijlstra
2007-09-26 1:46 ` CFS: new java yield graphs Antoine Martin
2007-09-27 8:35 ` Ingo Molnar
2007-09-19 20:00 ` CFS: some bad numbers with Java/database threading [FIXED] Chris Friesen
2007-09-14 16:01 ` CFS: some bad numbers with Java/database threading Satyam Sharma
2007-09-14 16:08 ` Satyam Sharma
2007-09-17 12:17 ` Antoine Martin
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