Am 09.09.24 um 19:19 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin <tvrtko.ursu...@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.ursu...@igalia.com>
Cc: Christian König <christian.koe...@amd.com>
Cc: Alex Deucher <alexander.deuc...@amd.com>
Cc: Luben Tuikov <ltuiko...@gmail.com>
Cc: Matthew Brost <matthew.br...@intel.com>
Cc: Philipp Stanner <pstan...@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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