Re: [PATCH] Add MCE resume under ia32

Andi Kleen
2005-08-24T03:58:35Z

[adding discuss to cc]

On Wednesday 24 August 2005 05:47, Shaohua Li wrote:
> On Wed, 2005-08-24 at 05:12 +0200, Andi Kleen wrote:
> > On Wednesday 24 August 2005 03:59, Shaohua Li wrote:
> > > On Wed, 2005-08-24 at 03:52 +0200, Andi Kleen wrote:
> > > > Shaohua Li <shaohua.li@intel.com> writes:
> > > > > x86-64 has resume support. It uses 'on_each_cpu' in resume method,
> > > > > which is known broken. We'd better fix it.
> > > >
> > > > What is broken with it?
> > >
> > > It's a sysdev. The resume method is invoked with interrupt disabled.
> >
> > But only local interrupt disabled, no?
> >
> > Hmm - didn't we have a WARN_ON(irqs_disabled()) in smp_call_function().
> >
> > Anyways, it'll probably still work for now because the system should
> > be synchronized at this point.
>
> We are using cpu hotplug framework for MP suspend/resume. When sysdev's
> resume is calling, APs actually aren't up. So it actually can't work.

Ok, that's a new problem.

There were recently some patches to add individual MCE entries
for each CPU to sysfs. They are only used for set up right now,
but perhaps they can be linked somehow to the cpu sysfs devices
and get suspend/resume events from there.

-Andi