stop_cpus_hard when multiple CPUs are panicking from an NMI

Andriy Gapon avg at FreeBSD.org
Sun Nov 25 12:55:37 UTC 2012


on 25/11/2012 14:29 Attilio Rao said the following:
> I think the patch you propose makes such effects even worse, because
> it disables interrupts in generic_stop_cpus().
> What I suggest to do, is the following:
> - The CPU which wins the race for generic_stop_cpus also signals the
> CPUs it is willing to stop on a global mask
> - Another CPU entering generic_stop_cpus() and loosing the race,
> checks the mask of cpus which might be stopped and stops itself if
> necessary (ie. not yet done). We must be careful with races here, but
> I'm confindent this can be done easily enough.

I think that you either misunderstood my patch or I misunderstand your
suggestion, because my patch does exactly what you wrote above.

-- 
Andriy Gapon


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