lkml.org 
[lkml]   [2007]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: 2.6.22-rc1: Broken suspend on SMP with tifm
Date
On Sunday, 13 May 2007 23:54, Oleg Nesterov wrote:
> On 05/13, Rafael J. Wysocki wrote:
> >
> > On Sunday, 13 May 2007 23:34, Oleg Nesterov wrote:
> > > On 05/13, Rafael J. Wysocki wrote:
> > > >
> > > > @@ -819,20 +843,31 @@ static int __devinit workqueue_cpu_callb
> > > >
> > > > +
> > > > + case CPU_DEAD_FROZEN:
> > > > + if (wq->freezeable) {
> > > > + take_over_work(wq, cpu);
> > > > + thaw_process(cwq->thread);
> > >
> > > Suppose that PF_NOFREEZE task T does flush_workqueue(), and CPU 1 has pending
> > > works. T does flush_cpu_workqueue(0), CPU_DEAD_FROZEN moves works from CPU 1
> > > to CPU 0, T does flush_cpu_workqueue(1) and finds nothing.
> >
> > I don't think this is possible, because we've acquired workqueue_mutex in
> > _cpu_down().
>
> Yes, we did... but flush_workqueue() doesn't take it?

I was looking at the 2.6.21 code, sorry.

Hmm, I guess we could add an additional mutex that would only be taken in
flush_workqueue() and in _cpu_down()/_cpu_up() via workqueue_cpu_callback()
with CPU_LOCK_ACQUIRE?

It doesn't seem to be a good idea to run flush_workqueue() while CPUs are being
taken up and down anyway.

Greetings,
Rafael
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-05-14 00:19    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site