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!

> > This sounds wrong to me. Shouldn't the the effect of hotunplugging a cpu be to 
> > put the driver in a state equivalent to if that cpu simply didn't exist? 
> > Unplugging shouldn't assume we're going to subsequently have either a driver 
> > suspend, or a replug.
> 
> This is my biggest problem or maybe my complete lack of understanding, is
> that I don't know how to determine what state I am in during a hotplug

Basically you can't/shouldn't determine that. 

> I thought it would make more sense if a few more states were to the
> hotplug event list.  For example, in addition to CPU_ONLINE and CPU_DEAD,
> there could also be something like CPU_SUSPEND, CPU_FREEZE, CPU_RESUME,
> and CPU_THAW.  
> 
> Anyway, I am probably complicating the matter.  I'll whip something up and
> post it for review.

I think you are overcomplicating this. Just forget about
suspend/resume, and reinit cpus from the scratch each time. It may
lead into some 'interesting' behaviour if someone tries to suspend
while profiling, but I believe we can live with that.
							Pavel
-- 
Thanks for all the (sleeping) penguins.