[Intel-gfx] [PATCH 04/22] drm/i915: Remove request retirement before each batch

[Joonas Lahtinen]

On ke, 2016-07-27 at 12:14 +0100, Chris Wilson wrote:
> This reimplements the denial-of-service protection against igt from
> commit 227f782e4667 ("drm/i915: Retire requests before creating a new
> one") and transfers the stall from before each batch into get_pages().
> The issue is that the stall is increasing latency between batches which
> is detrimental in some cases (especially coupled with execlists) to
> keeping the GPU well fed. Also we have made the observation that retiring
> requests can of itself free objects (and requests) and therefore makes
> a good first step when shrinking.
> 
> v2: Recycle objects prior to i915_gem_object_get_pages()
> v3: Remove the reference to the ring from i915_gem_requests_ring() as it
> operates on an intel_engine_cs.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Was this tested for performance regressions?

Codewise,

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation