Re: [PATCH] drm/i915: Flush outstanding unpin tasks before pageflipping

[Chris Wilson <chris@chris-wilson.co.uk>]

On Thu, 1 Nov 2012 09:04:02 -0700, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> On Thu, 01 Nov 2012 15:52:23 +0000
> Chris Wilson <chris@chris-wilson.co.uk> wrote:
> 
> > Actually I've justified the blocking here to myself, and prefer it to
> > simply running the crtc->unpin_work. If userspace is swamping the system
> > so badly that we can run the kthreads quick enough, it deserves a stall.
> > Note that the unpin leak is still about the 3rd most common bug in fedora,
> > so this stall will be forced on many machines.
> 
> Hm funky, why does Fedora hit it so much?  Does some of the GNOME shell
> stuff run unthrottled or something?

I don't think so. I trust that in Tvrtko's use case, he is not so much as
hogging the GPU as keeping the system as a whole relatively busy. So I
suspect it is more to do with CPU starvation of the kthreads than
anything else.

Tvrtko, do you have any feeling for why your machine was easily
suspectible to this leak? Are the stalls noticeable and do they affect
your performance targets?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre