From: Lee Revell <rlrevell@joe-job.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Softirq preemption
Date: Thu, 01 Dec 2005 14:08:50 -0500 [thread overview]
Message-ID: <1133464131.7898.30.camel@mindpipe> (raw)
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Ingo,
Is there any chance that the softirq preemption feature from the -rt
kernel can be pushed upstream?
Currently I am testing 2.6.14-rt21 with PREEMPT_DESKTOP and hard/softirq
preemption disabled in order to simulate the behavior of 2.6.14
mainline. The network TX softirq is the longest non-preemptible code
path, it can run for 5-6ms. However I can see that the preempt_count
drops to zero on many occasions, which IIRC means that no locks are held
and we could easily preempt at that point.
Without softirq preemption I don't see how we have any chance of meeting
the 1ms goal for desktop responsiveness that was decided on at OLS 2004.
Lee
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next reply other threads:[~2005-12-01 19:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-01 19:08 Lee Revell [this message]
2005-12-07 1:31 ` Softirq preemption Lee Revell
2005-12-07 9:02 ` Ingo Molnar
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