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Date: Wed, 6 Nov 2002 18:12:42 +0000
From: John Levon <levon@movementarian.org>
To: george anzinger <george@mvista.com>
Cc: Mikael Pettersson <mikpe@csd.uu.se>, Ingo Molnar <mingo@elte.hu>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: NMI watchdog question.
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On Wed, Nov 06, 2002 at 09:59:41AM -0800, george anzinger wrote:

> So then the NMI checks for timer interrupts being serviced
> in this case?  But, still, why the turn off if the timer
> does not go thru the APIC?  The case this came up in is an
> SMP machine, but the test in apic.c shows that the PIT
> interrupt does not go thru the APIC.  Leaving NMI on seems
> to work, so I am wondering if this is just old code.

It seems that the test should be :

	if (nmi_watchdog == NMI_IO_APIC) {
		... disable it
	}

I don't think the perfctr watchdog would be affected by the code in
io_apic.c

(on a vaguely related note, booting with nmi_watchdog=2 on my SMP
machine gives high rates of nmis :

janus:~# cat /proc/interrupts | grep NMI ; sleep 1 ; cat /proc/interrupts | grep NMI
NMI:      88358      88358
NMI:      88432      88397

when the machine is compiling kernels. I dunno why ...)

regards
john

-- 
"When a man has nothing to say, the worst thing he can do is to say it
memorably."
	- Calvin Trillin
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