[Intel-gfx] [PATCH v8] drm/i915: Squash repeated awaits on the same fence

[Chris Wilson]

On Thu, Apr 27, 2017 at 08:06:36AM +0100, Chris Wilson wrote:
> Track the latest fence waited upon on each context, and only add a new
> asynchronous wait if the new fence is more recent than the recorded
> fence for that context. This requires us to filter out unordered
> timelines, which are noted by DMA_FENCE_NO_CONTEXT. However, in the
> absence of a universal identifier, we have to use our own
> i915->mm.unordered_timeline token.

Fwiw, the conversion to a ht of leaves is
http://paste.debian.net/929577/

I don't like the compromise of the fixed size ht, it is too easy to hit
a badly performing case.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre