From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Tue, 22 May 2012 20:17:20 +0200
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Xenomai] CPU occupation without context switches?
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To: Arnout Vandecappelle <arnout@mind.be>
Cc: xenomai@xenomai.org

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.