From 4d97cbe01980c0d008d125903ef9ff05b6640c2d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 29 Jan 2019 18:54:51 +0000 Subject: 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 Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190129185452.20989-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_engine_cs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_engine_cs.c') diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 8dca76f6315d..0a610c9691fd 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -480,7 +480,7 @@ static void intel_engine_init_execlist(struct intel_engine_cs *engine) GEM_BUG_ON(!is_power_of_2(execlists_num_ports(execlists))); GEM_BUG_ON(execlists_num_ports(execlists) > EXECLIST_MAX_PORTS); - execlists->queue_priority = INT_MIN; + execlists->queue_priority_hint = INT_MIN; execlists->queue = RB_ROOT_CACHED; } @@ -1178,7 +1178,7 @@ void intel_engines_park(struct drm_i915_private *i915) } /* Must be reset upon idling, or we may miss the busy wakeup. */ - GEM_BUG_ON(engine->execlists.queue_priority != INT_MIN); + GEM_BUG_ON(engine->execlists.queue_priority_hint != INT_MIN); if (engine->park) engine->park(engine); -- cgit