Re: [Suspend2-devel] Re: CFS and suspend2: hang in atomic copy

Nigel Cunningham
2007-04-19T01:43:39Z

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Hi.

On Wed, 2007-04-18 at 18:56 -0400, Bob Picco wrote:
> Ingo Molnar wrote: [Wed Apr 18 2007, 06:02:28PM EDT]
> >
> > * Christian Hesse <mail@earthworm.de> wrote:
> >
> > > > although probably your suspend2 problem is still not fixed, it's
> > > > worth a try nevertheless. Which suspend2 patch did you apply, and
> > > > was it against -rc6 or -rc7?
> > >
> > > You are right again. ;-)
> > >
> > > Linux 2.6.21-rc7
> > > Suspend2 2.2.9.11 (applies cleanly to -rc7)
> > > CFS v3 (without any additional patches)
> > >
> > > And it still hangs on suspend.
> >
> > what's the easiest way for me to try suspend2? Apply the patch, reboot
> > into the kernel, then execute what command to suspend? (there's a
> > confusing mismash of initiators of all the suspend variants. Can i drive
> > this by echoing to /sys/power/state?)
> >
> > Ingo
> I had hoped to collect more data with CFS V2. It crashes in
> scale_nice_down for s2ram when attempting to disable_nonboot_cpus.
> So part of traceback looks like (typed by hand with obvious omissions):
>
> scale_nice_down
> update_stats_wait_end - not shown in traceback because inlined
> pick_next_task_fair
> migration_call
> task_rq_lock
> notifier_call_chain
> _cpu_down
> disable_nonboot_cpus
> ...
>
> This is standard -rc7 with V2 CFS applied. It could be a completely
> unrelated issue. I'll attempt to debug further tomorrow.

That - and Christian's other reply with the jpg - look to me more like
this is an interaction between CFS and cpu hotplugging than Suspend2
itself. Can you also reproduce this with swsusp?

Regards,

Nigel

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