Re: [2.6.17-rc5-mm2] crash when doing second suspend: BUG in arch/i386/kernel/nmi.c:174

[Andi Kleen <ak@suse.de>]

On Wednesday 07 June 2006 01:55, Don Zickus wrote:
> > > So my question is/was what is the proper way to handle processor level
> > > subsystems during the suspend/resume path on an SMP system.  I really
> > > don't understand the hotplug path nor the suspend/resume path very
> > > well.
> >
> > Make it work properly for CPU hotplug for individual CPU and then in
> > suspend you take care of "global" state and the last CPU.
>
> So the assumption is treat all the cpus the same either all on or all off,
> no mixed mode (some cpus on, some cpus off).  I guess I was trying to hard
> to work on the per-cpu level.

No, mixed should work of course.

>
> > > I didn't want to register a hotplug handler because a hotplug event is
> > > really different than a suspend event (I want to _save_ info during a
> > > suspend event).  The documentation I was reading seemed to suggest that
> > > hotplug/suspend/smp was a work-in-progress.
> >
> > You need to disable the nmi watchdog on CPU hotunplug too,
> > it's no good to keep the NMI running.
>
> Don't you want to make sure those CPUs are actually sleeping.  :^D

That is what i meant - they can't sleep if the NMI keeps running.
Ok it would run only for a short time for local APIC, but longer
for io apic

-Andi