From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Tue, 22 Jan 2013 23:27:21 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Xenomai] x86 Linux with xenomai and i915 graphics stall
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To: "Daniel M. Drucker, Ph.D." <dmd@interactive-motion.com>
Cc: xenomai@xenomai.org

On 01/22/2013 11:23 PM, Daniel M. Drucker, Ph.D. wrote:

> Hi Gilles et al.,
> 
>> That is unusual, a typical latency on x86 is under 50us (and this is a
>> conservative bound). In order to investigate this, enable the I-pipe
>> tracer in the kernel configuration and run latency -f. Also set the
>> number of backtrace points to a large value, say 1000 or 10000 and post
>> the trace here.
> 
> Here is the trace before running glxgears. The worst latency is 32us.
> 
> https://gist.github.com/raw/4599095/203ce77b2bb8e1b2c797302d33ce1a7b0a18fbac/gistfile1
> 
> And here is the trace while running glxgears. The worst latency is 724us.
> 
> https://gist.github.com/raw/4599099/27054c46f246999375346ed942f76d0757c4fa0a/gistfile1


And you are sure that it is not an SMI issue? Could you post your kernel
configuration?

-- 
                                                                Gilles.