Date: Mon, 14 Jan 2008 17:16:10 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Ed Tomlinson <edt@aei.ca>
Cc: Matthew <jackdachef@gmail.com>, "H. Peter Anvin" <hpa@zytor.com>,
       linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: Fwd: Fwd: laptop / computer hardlocks during execution of
	32bit applications(binaries) on 64bit system (Gentoo)
Message-ID: <20080114161610.GE15542@elte.hu>
References: <200801102122.51507.edt@aei.ca>
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* Ed Tomlinson <edt@aei.ca> wrote:

> >> - if yes, does booting with "nmi_watchdog=2 idle=poll" give you a
> >>   working NMI watchdog? (working NMI watchdog means the NMI counts 
> >>   increase for all cores in /proc/interrupts).
> 
> > booting with the above gives me an incrementing NMI counter in 
> > /proc/interrupts
> 
> Ingo,
> 
> Is there anything else that needs to be set in the kernel config for 
> the nmi watchdog to trigger?
> 
> I ask because I just had a hang but nothing showed on the _serial_ 
> console - I waited a couple of minutes before rebooting....  Is there 
> any other way to verify the watchdog is working?

if you cause a hard lockup intentionally via an infinite irqs-off loop:
  
# cat > lockupcli.c
main ()
{
	iopl(3);
	for (;;) asm("cli");
}
Ctrl-D
make lockupcli
./lockupcli

does the NMI watchdog properly trigger? If not, does booting with 
idle=poll change the situation?

	Ingo
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