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Date: Mon, 27 Jun 2005 10:15:42 +0200
From: Ingo Molnar <mingo@elte.hu>
To: William Weston <weston@sysex.net>
Cc: "K.R. Foley" <kr@cybsft.com>, linux-kernel@vger.kernel.org,
       "Eugeny S. Mints" <emints@ru.mvista.com>,
       Daniel Walker <dwalker@mvista.com>
Subject: Re: [patch] Real-Time Preemption, -RT-2.6.12-rc6-V0.7.48-00
Message-ID: <20050627081542.GA15096@elte.hu>
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* William Weston <weston@sysex.net> wrote:

> I still haven't been able to get any NMI watchdog traces with the 
> lockups induced by VLC and burnP6.  Early printk is enabled on the 
> serial console. I have noticed, however, that scheduling performance 
> slowly degrades during the ~1 minute before locking up.  Once I was 
> able to get a delayed SysRq response (~30s) from the serial console 
> after the X console became unresponsive.  Is this possibly a scheduler 
> starvation issue that affects everything, including the NMI watchdog?  
> Any more suggestions for catching a trace?

hm. Nothing should starve the NMI watchdog. Only a nasty, complete 
kernel crash or a hardware failure can lock up the box in a way that not 
even the NMI watchdog can get some message out to the console. Just in 
case, could you try the latest patch (-50-24 or later), there were a 
couple of bugs fixed.

	Ingo