[Intel-gfx] [PATCH 0/3] RFC: force throttling/fairness

[Ben Widawsky]

On Sat, 29 Oct 2011 11:45:34 -0700
Eric Anholt <eric at anholt.net> wrote:

> On Sat, 29 Oct 2011 09:07:35 +0100, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > On Fri, 28 Oct 2011 22:55:26 -0700, Ben Widawsky <ben at bwidawsk.net> wrote:
> > > These patches are pretty raw as I'm hoping to get some comments before
> > > working to hard too clean them up. The goal is GPU fairness for clients
> > > running on i915.
> > 
> > The biggest danger I see is that num_outstanding is only decremented
> > in retire_requests, which under the right circumstances (a single hog or
> > a plurarity) will cause latencies of over 1s. Also this unnecessarily
> > penalises benchmarks, i.e. a single active client.
> 
> Just using wait_request interface would require less code and not have
> that issue.

I must be missing something simple, but I didn't see an easy way to use
that interface to do what I want. Instead of outstanding requests, I'd
need to start tracking per fd seqnos (yes it's done elsewhere, but
didn't seem much different to me).

Can you explain what I'm missing?

Ben