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Date: Fri, 01 May 2009 14:35:44 -0700
From: Thomas Lockhart <Thomas.Lockhart@domain.hid>
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Subject: Re: [Xenomai-help] rtdm_event_timedwait returns -EINTR
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To: Philippe Gerum <rpm@xenomai.org>
Cc: Petr Cervenka <grugh@domain.hid>, xenomai-help <xenomai@xenomai.org>, "Lockhart, Thomas G" <thomas.g.lockhart@domain.hid>

>  Mmm, actually, I would bet that this latency is caused by an
>  inter-CPU TLB flush request; this is a bug fixed in recent releases
>  of the I-pipe patch, both for 2.6.28.9 and 2.6.29.1. There is no
>  backport for 2.6.26, but you should be able to apply this commit
>  manually:
> 
http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=69f7e0c005eca37a04104dd85f30095791e8c2f7

That was easy to patch manually and seems to have helped a lot. I'm 
still seeing an occasional "spike" of about 35usec or so every few 
minutes but the majority of the spikes (hmm, the latency is still pretty 
good so I hate to call them spikes; maybe "bumps"?) have gone away. 
Thanks for the suggestion!

Would it be helpful if I integrated this patch into the 2.6.26 support?

                                      - Tom