From d42a254633c773921884a19e8a1a0f53a31150c3 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Wed, 16 Oct 2024 13:20:09 +0100 Subject: drm/sched: Optimise drm_sched_entity_push_job MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In FIFO mode (which is the default), both drm_sched_entity_push_job() and drm_sched_rq_update_fifo(), where the latter calls the former, are currently taking and releasing the same entity->rq_lock. We can avoid that design inelegance, and also have a miniscule efficiency improvement on the submit from idle path, by introducing a new drm_sched_rq_update_fifo_locked() helper and pulling up the lock taking to its callers. v2: * Remove drm_sched_rq_update_fifo() altogether. (Christian) v3: * Improved commit message. (Philipp) Signed-off-by: Tvrtko Ursulin Cc: Christian König Cc: Alex Deucher Cc: Luben Tuikov Cc: Matthew Brost Cc: Philipp Stanner Reviewed-by: Christian König Signed-off-by: Philipp Stanner Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-2-tursulin@igalia.com --- drivers/gpu/drm/scheduler/sched_entity.c | 13 +++++++++---- drivers/gpu/drm/scheduler/sched_main.c | 6 +++--- 2 files changed, 12 insertions(+), 7 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 2951fcc2e6b1..b72cba292839 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -514,8 +514,12 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) struct drm_sched_job *next; next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); - if (next) - drm_sched_rq_update_fifo(entity, next->submit_ts); + if (next) { + spin_lock(&entity->rq_lock); + drm_sched_rq_update_fifo_locked(entity, + next->submit_ts); + spin_unlock(&entity->rq_lock); + } } /* Jobs and entities might have different lifecycles. Since we're @@ -613,10 +617,11 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) sched = rq->sched; drm_sched_rq_add_entity(rq, entity); - spin_unlock(&entity->rq_lock); if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) - drm_sched_rq_update_fifo(entity, submit_ts); + drm_sched_rq_update_fifo_locked(entity, submit_ts); + + spin_unlock(&entity->rq_lock); drm_sched_wakeup(sched); } diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 36db5c7736fc..f2d47b382bdb 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -163,14 +163,15 @@ static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *enti } } -void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) +void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts) { /* * Both locks need to be grabbed, one to protect from entity->rq change * for entity from within concurrent drm_sched_entity_select_rq and the * other to update the rb tree structure. */ - spin_lock(&entity->rq_lock); + lockdep_assert_held(&entity->rq_lock); + spin_lock(&entity->rq->lock); drm_sched_rq_remove_fifo_locked(entity); @@ -181,7 +182,6 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) drm_sched_entity_compare_before); spin_unlock(&entity->rq->lock); - spin_unlock(&entity->rq_lock); } /** -- cgit