diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-01-29 18:54:51 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-01-29 20:00:03 +0000 |
| commit | 4d97cbe01980c0d008d125903ef9ff05b6640c2d (patch) | |
| tree | e4d19ef9b20005bfa14f1698cc9c4c79cb146761 /drivers/gpu/drm/i915/intel_ringbuffer.h | |
| parent | 8547444137ec6138ce52fc1938980b737a0d4d9e (diff) | |
drm/i915: Rename execlists->queue_priority to queue_priority_hint
After noticing that we trigger preemption events for currently executing
requests, as well as requests that complete before the preemption and
attempting to suppress those preemption events, it is wise to not
consider the queue_priority to be authoritative. As we only track the
maximum priority seen between dequeue passes, if the maximum priority
request is no longer available for dequeuing (it completed or is even
executing on another engine), we have no knowledge of the previous
queue_priority as it would require us to keep a full history of enqueued
requests -- but we already have that history in the priolists!
Rename the queue_priority to queue_priority_hint so that we do not
confuse it as being exactly the maximum priority in the queue, but merely
an indication that we have seen a new maximum priority value and as such
we should check whether it should preempt the currently running request.
v2: s/preempt_priority_hint/queue_priority_hint/ as preempt implies it
being only used for the singular task of preemption and not the wider
question of waking up due to a change in the queue.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129185452.20989-3-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.h')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ringbuffer.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 1f30ffb84936..ef024c154a1b 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -293,14 +293,18 @@ struct intel_engine_execlists { unsigned int port_mask; /** - * @queue_priority: Highest pending priority. + * @queue_priority_hint: Highest pending priority. * * When we add requests into the queue, or adjust the priority of * executing requests, we compute the maximum priority of those * pending requests. We can then use this value to determine if * we need to preempt the executing requests to service the queue. + * However, since the we may have recorded the priority of an inflight + * request we wanted to preempt but since completed, at the time of + * dequeuing the priority hint may no longer may match the highest + * available request priority. */ - int queue_priority; + int queue_priority_hint; /** * @queue: queue of requests, in priority lists |