Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8)

From: Matthew Garrett
Date: Thu May 27 2010 - 13:53:27 EST


On Thu, May 27, 2010 at 07:46:37PM +0200, Peter Zijlstra wrote:
> On Thu, 2010-05-27 at 18:41 +0100, Matthew Garrett wrote:
> > On Thu, May 27, 2010 at 07:35:50PM +0200, Peter Zijlstra wrote:
> > > Then that's an application bug right there, isn't it?
> > >
> > > If should have listened to the window server telling its clients it was
> > > going to go away. Drawing after you get that is your own damn fault ;-)
> >
> > How long do you wait for applications to respond that they've stopped
> > drawing? What if the application is heavily in swap at the time?
>
> Since we're talking about a purely idle driven power saving, we wait
> until the cpu is idle.

If that's what you're aiming for then you don't need to block
applications on hardware access because they should all already have
idled themselves.

> Note that it doesn't need to broadcast this, it could opt to reply with
> that message on the first drawing attempt after it goes away and block
> on the second.

That's more interesting, but you're changing semantics quite heavily at
this point.

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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