[Intel-gfx] [PATCH] drm/i915/ppgtt: Limit guilty hunt inside of relevant vm

[Chris Wilson]

On Fri, Jan 17, 2014 at 12:03:24PM +0200, Mika Kuoppala wrote:
> With full ppgtt, ACTHD is only relevant inside one context
> (address space). Trying to find guilty batch only relying
> on ACTHD, the result is false positives as ACTHD points
> inside batches on different address spaces.
> 
> Filter out nonrelated contexts by checking on which vm
> the ring was running on when the hang happened. Only after
> finding the relevant vm, use acthd to find the guilty
> batch inside it.

Alternatively (or in addtion to) you could walk the request
list backwards and stop searching for guilty requests after
the first hit.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre