Re: [RFC][PATCH -mm 2/2] Freezer: Use wait queue instead of busy looping

Pavel Machek
2007-07-31T10:00:31Z

Hi!

> > Ok, could we just do schedule_timeout(HZ/10) or something, but when we
> > _know_ we woke someone, wakeup() that task? No new variables, keep
> > existing logic.
>
> The logic doesn't change that much. :-)
>
> > That should still get most of the benefits, and be two liner, no?
>
> Well, I think we can avoid using refrigerator_called, if this is a problem, but
> the patch won't be a two liner.

Sure? The current process is ineffective because it polls. If we add
schedule_timeout(HZ/10), we'll have still correct freezer (and it will
not waste power any more), but it will delay freezing by HZ/20 on
average.

If we add wakeup() at strategic place, we should get rid of that delay...

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html