linux-kernel - Re: Mysterious freezes after 2.6.35, no NMI

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Message-ID: <20110419143031.GA21993@redhat.com>
Date:	Tue, 19 Apr 2011 10:30:31 -0400
From:	Don Zickus <dzickus@...hat.com>
To:	Nicos Gollan <ngollan@...arhead.de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Mysterious freezes after 2.6.35, no NMI

On Tue, Apr 12, 2011 at 07:39:59PM +0200, Nicos Gollan wrote:
> To add insult to injury, at least in the 2.6.38 series, the NMI watchdog is 
> broken. The counters in /proc/interrupts always show 0, but will count up 
> quite happily on 2.6.35.

The nmi watchdog changed for 2.6.36, such that it increments every 60
seconds instead of every second.  Using cpuspeed and a lightly loaded
system, will delay it even longer.  This is a good thing as you don't need
nmi interrupts firing all the time.

But if after sticking a load on the system for 10 minutes, the NMI
interrupt doesn't increment, then I would be concerned.

Cheers,
Don
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