[PATCH 4/8] drm/sched: Optimise drm_sched_entity_push_job
Christian König
ckoenig.leichtzumerken at gmail.com
Tue Sep 10 08:36:47 UTC 2024
Am 09.09.24 um 19:19 schrieb Tvrtko Ursulin:
> From: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
>
> In FIFO mode We can avoid dropping the lock only to immediately re-acquire
> by adding a new drm_sched_rq_update_fifo_locked() helper.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Luben Tuikov <ltuikov89 at gmail.com>
> Cc: Matthew Brost <matthew.brost at intel.com>
> Cc: Philipp Stanner <pstanner at redhat.com>
> ---
> drivers/gpu/drm/scheduler/sched_entity.c | 5 +++--
> drivers/gpu/drm/scheduler/sched_main.c | 21 ++++++++++++++-------
> include/drm/gpu_scheduler.h | 1 +
> 3 files changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
> index 6645a8524699..2da677681291 100644
> --- a/drivers/gpu/drm/scheduler/sched_entity.c
> +++ b/drivers/gpu/drm/scheduler/sched_entity.c
> @@ -615,10 +615,11 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
>
> atomic_inc(sched->score);
> 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, entity);
> }
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index ab53ab486fe6..10abbcefe9d8 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -163,14 +163,10 @@ 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);
> @@ -181,6 +177,17 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
> drm_sched_entity_compare_before);
>
> spin_unlock(&entity->rq->lock);
> +}
> +
> +void drm_sched_rq_update_fifo(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);
> + drm_sched_rq_update_fifo_locked(entity, ts);
> spin_unlock(&entity->rq_lock);
> }
I wonder if we shouldn't change the only other occasion calling this to
grab the lock manually as well.
Christian.
>
> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> index fe8edb917360..a06753987d93 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -594,6 +594,7 @@ void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
> struct drm_sched_entity *entity);
>
> 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);
>
> int drm_sched_entity_init(struct drm_sched_entity *entity,
> enum drm_sched_priority priority,
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