Commit 71ed6011 authored by Matthew Brost's avatar Matthew Brost Committed by Matt Roper
Browse files

drm/i915: Add kick_backend function to i915_sched_engine 



Not all back-ends require a kick after a  scheduling update, so make the
kick a call-back function that the  back-end can opt-in to. Also move
the current kick function from the scheduler to the execlists file as it
is specific to that back-end.

Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210618010638.98941-7-matthew.brost@intel.com
parent 3f623e06

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

+52 −0
Original line number Diff line number Diff line
@@ -3116,10 +3116,61 @@ static bool can_preempt(struct intel_engine_cs *engine) 
	return engine->class != RENDER_CLASS;

}



static void kick_execlists(const struct i915_request *rq, int prio)

{

	struct intel_engine_cs *engine = rq->engine;

	struct i915_sched_engine *sched_engine = engine->sched_engine;

	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 <= sched_engine->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

	 * bother evaluating if we should preempt ourselves.

	 */

	if (inflight->context == rq->context)

		goto unlock;



	ENGINE_TRACE(engine,

		     "bumping queue-priority-hint:%d for rq:%llx:%lld, inflight:%llx:%lld prio %d\n",

		     prio,

		     rq->fence.context, rq->fence.seqno,

		     inflight->fence.context, inflight->fence.seqno,

		     inflight->sched.attr.priority);



	sched_engine->queue_priority_hint = prio;



	/*

	 * 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.

	 */

	if (prio >= max(I915_PRIORITY_NORMAL, rq_prio(inflight)))

		tasklet_hi_schedule(&engine->execlists.tasklet);



unlock:

	rcu_read_unlock();

}



static void execlists_set_default_submission(struct intel_engine_cs *engine)

{

	engine->submit_request = execlists_submit_request;

	engine->sched_engine->schedule = i915_schedule;

	engine->sched_engine->kick_backend = kick_execlists;

	engine->execlists.tasklet.callback = execlists_submission_tasklet;

}
@@ -3702,6 +3753,7 @@ intel_execlists_create_virtual(struct intel_engine_cs **siblings, 
	ve->base.request_alloc = execlists_request_alloc;



	ve->base.sched_engine->schedule = i915_schedule;

	ve->base.sched_engine->kick_backend = kick_execlists;

	ve->base.submit_request = virtual_submit_request;

	ve->base.bond_execute = virtual_bond_execute;

drivers/gpu/drm/i915/i915_scheduler.c

+2 −60
Original line number Diff line number Diff line
@@ -157,65 +157,6 @@ sched_lock_engine(const struct i915_sched_node *node, 
	return locked;

}



static inline int rq_prio(const struct i915_request *rq)

{

	return rq->sched.attr.priority;

}



static inline bool need_preempt(int prio, int 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->sched_engine->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

	 * bother evaluating if we should preempt ourselves.

	 */

	if (inflight->context == rq->context)

		goto unlock;



	ENGINE_TRACE(engine,

		     "bumping queue-priority-hint:%d for rq:%llx:%lld, inflight:%llx:%lld prio %d\n",

		     prio,

		     rq->fence.context, rq->fence.seqno,

		     inflight->fence.context, inflight->fence.seqno,

		     inflight->sched.attr.priority);



	engine->sched_engine->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,

			    const struct i915_sched_attr *attr)

{
@@ -335,7 +276,8 @@ static void __i915_schedule(struct i915_sched_node *node, 
		}



		/* Defer (tasklet) submission until after all of our updates. */

		kick_submission(engine, node_to_request(node), prio);

		if (engine->sched_engine->kick_backend)

			engine->sched_engine->kick_backend(node_to_request(node), prio);

	}



	spin_unlock(&engine->sched_engine->lock);

drivers/gpu/drm/i915/i915_scheduler_types.h

+6 −0
Original line number Diff line number Diff line
@@ -153,6 +153,12 @@ struct i915_sched_engine { 
	 */

	bool no_priolist;



	/**

	 * @kick_backend: kick backend after a request's priority has changed

	 */

	void	(*kick_backend)(const struct i915_request *rq,

				int prio);



	/**

	 * @schedule: adjust priority of request

	 *