linux/drivers/gpu
Chris Wilson c2314b8bd4 drm/i915/gem: Reduce context termination list iteration guard to RCU
As we now protect the timeline list using RCU, we can drop the
timeline->mutex for guarding the list iteration during context close, as
we are searching for an inflight request. Any new request will see the
context is banned and not be submitted. In doing so, pull the checks for
a concurrent submission of the request (notably the
i915_request_completed()) under the engine spinlock, to fully serialise
with __i915_request_submit()). That is in the case of preempt-to-busy
where the request may be completed during the __i915_request_submit(),
we need to be careful that we sample the request status after
serialising so that we don't miss the request the engine is actually
submitting.

Fixes: 4a31741521 ("drm/i915/gem: Refine occupancy test in kill_context()")
References: d22d2d073e ("drm/i915: Protect i915_request_await_start from early waits") # rcu protection of timeline->requests
References: https://gitlab.freedesktop.org/drm/intel/-/issues/1622
References: https://gitlab.freedesktop.org/drm/intel/-/issues/2158
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200806105954.7766-1-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
(cherry picked from commit 736e785f9b)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2020-09-16 11:09:43 +03:00
..
drm drm/i915/gem: Reduce context termination list iteration guard to RCU 2020-09-16 11:09:43 +03:00
host1x gpu: host1x: debug: Dump push buffer state 2020-07-17 16:06:14 +02:00
ipu-v3 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
trace
vga vgaarb: mark vga_tryget static 2020-08-01 11:28:17 +02:00
Makefile