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

[Pavel Machek <pavel@suse.cz>]

Hi!

> > >All the above applies to suspend-to-disk.  I don't know if suspend-to-RAM
> > >shuts down the APs.
> > >  
> > 
> > I'm using suspend-to-mem and it looks like its unplugging/replugging all 
> > the CPUs.
> > 
> > The part of the question I don't quite understand is why this is 
> > considered per-CPU state?  Surely NMI-watchdog is a system-wide thing?  
> > Or does this also tie into other uses of the performance registers which 
> > may be set per-CPU?
> 
> The nmi watchdog is enable/disabled on a per-cpu basis.  The fact that a
> single switch turns all of them on/off is just convienance.  Adding in
> code to turn them on/off on a per-cpu basis just requires a simple user
> interface.  It has been talked about before to deal with NUMA systems. 

Does it make sense to run watchdog on cpu 1 but not on cpu 0? If user
plugs cpu 2, should it get watchdog or not? If I unplug cpu 1 and plug
it back, should it run watchdog or not?

I believe it should be per-system thing.
							Pavel
-- 
Thanks for all the (sleeping) penguins.