Re: [patch 2/2] sched: fix nr_uninterruptible accounting of frozentasks really

From: Matt Helsley
Date: Fri Jul 17 2009 - 12:20:15 EST


On Fri, Jul 17, 2009 at 05:55:27PM +0200, Peter Zijlstra wrote:
> On Fri, 2009-07-17 at 08:51 -0700, Matt Helsley wrote:
>
> > So it's not clear to me how adding PF_FREEZING fixes anything. Am I
> > missing something?
>
> Yep, PF_FROZEN is only observed going into schedule(), on the way back
> out thaw_process() will already have cleared the flag.
>
> So we don't increment in deactivate_task(), but we do decrement in
> activate_task(), yielding for some very unbalanced accounting.

Ahhh, right!

OK, so the fix looks good then.

Cheers,
-Matt Helsley
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