From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To: Arnout Vandecappelle <arnout@mind.be>
Cc: xenomai@xenomai.org
Subject: Re: [Xenomai] CPU occupation without context switches?
Date: Tue, 22 May 2012 20:17:20 +0200 [thread overview]
Message-ID: <4FBBD830.4010407@xenomai.org> (raw)
In-Reply-To: <4FBBBA25.5010308@mind.be>
On 05/22/2012 06:09 PM, Arnout Vandecappelle wrote:
> Hoi,
>
> After a few minutes of running my application, I see this:
>
> # cat /proc/xenomai/stat
> CPU PID MSW CSW PF STAT %CPU NAME
> 1 828 22 65 0 00300182 9.8 bench_RTnet_scope_thread_loop
> 1 839 2 46627538 0 00300186 53.8 bench_RTnet
> ...
>
> i.e. the bench_RTnet_scope_thread_loop takes 10% CPU but no
> context switches. How is this possible? I've looked at the
> source code and can't find an explanation: when the exectime
> accounting is updated, the csw is incremented as well (in
> __xnpod_schedule()).
>
> I'm asking because I can't find a reason why this thread should
> occupy 10% of the CPU, so I'm wondering if there's something wrong
> with the accounting instead.
>
> BTW this is on Xenomai 2.5.6, on an SMP x86 with affinity=0x01.
Could you test Xenomai 2.6.0 to see if you still have the issue? Could
you provide us with some minimal code allowing us to reproduce this issue?
--
Gilles.
next prev parent reply other threads:[~2012-05-22 18:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-22 16:09 [Xenomai] CPU occupation without context switches? Arnout Vandecappelle
2012-05-22 18:17 ` Gilles Chanteperdrix [this message]
2012-05-22 19:44 ` Philippe Gerum
2012-05-23 8:31 ` Arnout Vandecappelle
2012-05-23 8:45 ` Philippe Gerum
2012-05-23 9:37 ` Philippe Gerum
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