diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_scheduler.c | 50 |
1 files changed, 39 insertions, 11 deletions
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c index 7b84ebca2901..3eba8a2b39c2 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.c +++ b/drivers/gpu/drm/i915/i915_scheduler.c @@ -177,9 +177,37 @@ static inline int rq_prio(const struct i915_request *rq) return rq->sched.attr.priority | __NO_PREEMPTION; } -static void kick_submission(struct intel_engine_cs *engine, int prio) +static inline bool need_preempt(int prio, int active) { - const struct i915_request *inflight = *engine->execlists.active; + /* + * Allow preemption of low -> normal -> high, but we do + * not allow low priority tasks to preempt other low priority + * tasks under the impression that latency for low priority + * tasks does not matter (as much as background throughput), + * so kiss. + */ + return prio >= max(I915_PRIORITY_NORMAL, active); +} + +static void kick_submission(struct intel_engine_cs *engine, + const struct i915_request *rq, + int prio) +{ + const struct i915_request *inflight; + + /* + * We only need to kick the tasklet once for the high priority + * new context we add into the queue. + */ + if (prio <= engine->execlists.queue_priority_hint) + return; + + rcu_read_lock(); + + /* Nothing currently active? We're overdue for a submission! */ + inflight = execlists_active(&engine->execlists); + if (!inflight) + goto unlock; /* * If we are already the currently executing context, don't @@ -188,10 +216,15 @@ static void kick_submission(struct intel_engine_cs *engine, int prio) * tasklet, i.e. we have not change the priority queue * sufficiently to oust the running context. */ - if (!inflight || !i915_scheduler_need_preempt(prio, rq_prio(inflight))) - return; + if (inflight->hw_context == rq->hw_context) + goto unlock; - tasklet_hi_schedule(&engine->execlists.tasklet); + engine->execlists.queue_priority_hint = prio; + if (need_preempt(prio, rq_prio(inflight))) + tasklet_hi_schedule(&engine->execlists.tasklet); + +unlock: + rcu_read_unlock(); } static void __i915_schedule(struct i915_sched_node *node, @@ -317,13 +350,8 @@ static void __i915_schedule(struct i915_sched_node *node, list_move_tail(&node->link, cache.priolist); } - if (prio <= engine->execlists.queue_priority_hint) - continue; - - engine->execlists.queue_priority_hint = prio; - /* Defer (tasklet) submission until after all of our updates. */ - kick_submission(engine, prio); + kick_submission(engine, node_to_request(node), prio); } spin_unlock(&engine->active.lock); |