drm/i915: Stop tracking execlists retired requests
authorTvrtko Ursulin <tvrtko@ursulin.net>
Thu, 28 Apr 2016 08:56:58 +0000 (09:56 +0100)
committerChris Wilson <chris@chris-wilson.co.uk>
Thu, 28 Apr 2016 11:17:32 +0000 (12:17 +0100)
commite39d42fa7e8bdd1ae88da6c7acbe04d8a68f130f
treeb74c731cb117bcdf18ba542e5e3f6b9a348aa560
parenta3d127616eef78d0e4a677b6634dbc914ff4fd0a
drm/i915: Stop tracking execlists retired requests

With the previous patch having extended the pinned lifetime of
contexts by referencing the previous context from the current
request until the latter is retired (completed by the GPU),
we can now remove usage of execlist retired queue entirely.

This is because the above now guarantees that all execlist
object access requirements are satisfied by this new tracking,
and we can stop taking additional references and stop keeping
request on the execlists retired queue.

The latter was a source of significant scalability issues in
the driver causing performance hits on some tests. Most
dramatical of which was igt/gem_close_race which had run time
in tens of minutes which is now reduced to tens of seconds.

Signed-off-by: Tvrtko Ursulin <tvrtko@ursulin.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-24-git-send-email-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_gem.c
drivers/gpu/drm/i915/intel_lrc.c
drivers/gpu/drm/i915/intel_lrc.h
drivers/gpu/drm/i915/intel_ringbuffer.h