[Intel-gfx] [PATCH] RFC drm/i915: Slaughter the thundering i915_wait_request herd

[Chris Wilson]

On Tue, Nov 03, 2015 at 03:06:36AM +0000, Gong, Zhipeng wrote:
> It seems that there are some gaps in the patch and first patch. 
> Like there is no this line in the first patch. 
>       if (req->ring->seqno_barrier)

Ah, that was in the context I hope...

> I have tried to apply this patch. And here is the cpu utilization and perf data on BDW

Do you also have a relative perf statistics like op/s we can compare to
make sure we aren't just stalling the whole system?
 
> CPU util      |	w/o patch  |   w/ patch
> ----------------------------------------------------------
> BDW async 1   |   116%     |     95%
> BDW async 5   |   111%     |     91%

How much cpu time is left in the i915_wait_request branch? i.e. how
close to the limit are we with chasing this path?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre