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

["Rafael J. Wysocki" <rjw@sisk.pl>]

Hi,

On Wednesday 07 June 2006 02:42, Don Zickus wrote:
> On Wed, Jun 07, 2006 at 10:05:07AM +1000, Nigel Cunningham wrote:
> > On Wednesday 07 June 2006 09:55, 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.
> > 
> > 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
> event, either a cpu removal or a suspend.  Therefore I feel like I have to
> store some persistant data around _just_ in case this is a suspend event.
> Also at the opposite end, how to separate a cpu insert vs. a cpu resume.
> The different being initialize to a global state vs. initialize to a last
> known state.

The original idea was to treat the nonboot CPUs as though they were removed.

Greetings,
Rafael