Re: Confusing behaviour with /proc/sys/kernel/nmi_watchdog

From: Anton Blanchard
Date: Wed Nov 05 2014 - 13:54:06 EST



Hi Don,

> > commit 9919e39a1738 ("kvm: ensure hard lockup detection is disabled
> > by default") provided a way for the kernel to disable the hard
> > lockup detector at runtime.
> >
> > I'm using it on ppc64 but notice some weird behaviour with the
> > nmi_watchdog procfs variable. At boot, that the hard lockup
> > detector appears to be enabled even when we disable it via
> > watchdog_enable_hardlockup_detector(false):
> >
> > # cat /proc/sys/kernel/nmi_watchdog
> > 1
> >
> > I have to echo 0 to it then echo 1 again to enable it.
>
> I believe Andrew answered the question for you, it's a WIP and we have
> patches to clean that up.

Thanks, yes good to see it being worked on.

> I don't see ppc64 watchdog support in arch/powerpc, is that something
> you are working with on implementing?

I've submitted it over on linuxppc-dev:

http://patchwork.ozlabs.org/patch/406802/

Anton
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