Re: Bisected post-3.9 regression: Resume takes 5 times as much timeas with v3.9

From: Borislav Petkov
Date: Sun May 12 2013 - 12:27:38 EST


On Sun, May 12, 2013 at 06:13:34PM +0200, BjÃrn Mork wrote:
> diff --git a/kernel/rcutree.c b/kernel/rcutree.c
> index 6934238..2dcbf84 100644
> --- a/kernel/rcutree.c
> +++ b/kernel/rcutree.c
> @@ -3103,9 +3103,11 @@ static int rcu_pm_notify(struct notifier_block *self,
> {
> switch (action) {
> case PM_HIBERNATION_PREPARE:
> + case PM_SUSPEND_PREPARE:
> rcu_expedited = 1;
> break;
> - case PM_POST_RESTORE:
> + case PM_POST_HIBERNATION:
> + case PM_POST_SUSPEND:
> rcu_expedited = 0;
> break;
> default:

If I'm reading Documentation/power/notifiers.txt correctly, we only need
PM_HIBERNATION_PREPARE when we go to sleep (whatever hibernation method
we use) and PM_POST_HIBERNATION when we restore.

I don't think it matters for expediting RCU grace periods whether
we had an error during resume or not and I'd basically want to set
rcu_expedited to 0 unconditionally when resuming..

Hmm.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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