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/i915_scheduler.c | |
| 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/i915_scheduler.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_scheduler.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c index 340faea6c08a..4eeba588b996 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.c +++ b/drivers/gpu/drm/i915/i915_scheduler.c @@ -127,8 +127,7 @@ static inline struct i915_priolist *to_priolist(struct rb_node *rb) return rb_entry(rb, struct i915_priolist, node); } -static void assert_priolists(struct intel_engine_execlists * const execlists, - long queue_priority) +static void assert_priolists(struct intel_engine_execlists * const execlists) { struct rb_node *rb; long last_prio, i; @@ -139,7 +138,7 @@ static void assert_priolists(struct intel_engine_execlists * const execlists, GEM_BUG_ON(rb_first_cached(&execlists->queue) != rb_first(&execlists->queue.rb_root)); - last_prio = (queue_priority >> I915_USER_PRIORITY_SHIFT) + 1; + last_prio = (INT_MAX >> I915_USER_PRIORITY_SHIFT) + 1; for (rb = rb_first_cached(&execlists->queue); rb; rb = rb_next(rb)) { const struct i915_priolist *p = to_priolist(rb); @@ -166,7 +165,7 @@ i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio) int idx, i; lockdep_assert_held(&engine->timeline.lock); - assert_priolists(execlists, INT_MAX); + assert_priolists(execlists); /* buckets sorted from highest [in slot 0] to lowest priority */ idx = I915_PRIORITY_COUNT - (prio & I915_PRIORITY_MASK) - 1; @@ -353,7 +352,7 @@ static void __i915_schedule(struct i915_request *rq, continue; } - if (prio <= engine->execlists.queue_priority) + if (prio <= engine->execlists.queue_priority_hint) continue; /* @@ -366,7 +365,7 @@ static void __i915_schedule(struct i915_request *rq, continue; /* Defer (tasklet) submission until after all of our updates. */ - engine->execlists.queue_priority = prio; + engine->execlists.queue_priority_hint = prio; tasklet_hi_schedule(&engine->execlists.tasklet); } |