Ping Christian and Philipp - reasonably happy with v2? I think it's the only unreviewed patch from the series.

Regards,

Tvrtko

On 16/09/2024 18:30, Tvrtko Ursulin wrote:
From: Tvrtko Ursulin <tvrtko.ursu...@igalia.com>

Having removed one re-lock cycle on the entity->lock in a patch titled
"drm/sched: Optimise drm_sched_entity_push_job", with only a tiny bit
larger refactoring we can do the same optimisation on the rq->lock.
(Currently both drm_sched_rq_add_entity() and
drm_sched_rq_update_fifo_locked() take and release the same lock.)

To achieve this we make drm_sched_rq_update_fifo_locked() and
drm_sched_rq_add_entity() expect the rq->lock to be held.

We also align drm_sched_rq_update_fifo_locked(),
drm_sched_rq_add_entity() and
drm_sched_rq_remove_fifo_locked() function signatures, by adding rq as a
parameter to the latter.

v2:
  * Fix after rebase of the series.
  * Avoid naming incosistency between drm_sched_rq_add/remove. (Christian)

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 | 12 ++++++++--
  drivers/gpu/drm/scheduler/sched_main.c   | 29 ++++++++++++------------
  include/drm/gpu_scheduler.h              |  3 ++-
  3 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c 
b/drivers/gpu/drm/scheduler/sched_entity.c
index d982cebc6bee..8ace1f1ea66b 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -515,9 +515,14 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct 
drm_sched_entity *entity)
next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
                if (next) {
+                       struct drm_sched_rq *rq;
+
                        spin_lock(&entity->lock);
-                       drm_sched_rq_update_fifo_locked(entity,
+                       rq = entity->rq;
+                       spin_lock(&rq->lock);
+                       drm_sched_rq_update_fifo_locked(entity, rq,
                                                        next->submit_ts);
+                       spin_unlock(&rq->lock);
                        spin_unlock(&entity->lock);
                }
        }
@@ -618,11 +623,14 @@ void drm_sched_entity_push_job(struct drm_sched_job 
*sched_job)
                sched = rq->sched;
atomic_inc(sched->score);
+
+               spin_lock(&rq->lock);
                drm_sched_rq_add_entity(rq, entity);
if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
-                       drm_sched_rq_update_fifo_locked(entity, submit_ts);
+                       drm_sched_rq_update_fifo_locked(entity, rq, submit_ts);
+ spin_unlock(&rq->lock);
                spin_unlock(&entity->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 18a952f73ecb..5c83fb92bb89 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -153,17 +153,18 @@ static __always_inline bool 
drm_sched_entity_compare_before(struct rb_node *a,
        return ktime_before(ent_a->oldest_job_waiting, 
ent_b->oldest_job_waiting);
  }
-static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity)
+static void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity,
+                                           struct drm_sched_rq *rq)
  {
-       struct drm_sched_rq *rq = entity->rq;
-
        if (!RB_EMPTY_NODE(&entity->rb_tree_node)) {
                rb_erase_cached(&entity->rb_tree_node, &rq->rb_tree_root);
                RB_CLEAR_NODE(&entity->rb_tree_node);
        }
  }
-void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts)
+void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity,
+                                    struct drm_sched_rq *rq,
+                                    ktime_t ts)
  {
        /*
         * Both locks need to be grabbed, one to protect from entity->rq change
@@ -171,17 +172,14 @@ void drm_sched_rq_update_fifo_locked(struct 
drm_sched_entity *entity, ktime_t ts
         * other to update the rb tree structure.
         */
        lockdep_assert_held(&entity->lock);
+       lockdep_assert_held(&rq->lock);
- spin_lock(&entity->rq->lock);
-
-       drm_sched_rq_remove_fifo_locked(entity);
+       drm_sched_rq_remove_fifo_locked(entity, rq);
entity->oldest_job_waiting = ts; - rb_add_cached(&entity->rb_tree_node, &entity->rq->rb_tree_root,
+       rb_add_cached(&entity->rb_tree_node, &rq->rb_tree_root,
                      drm_sched_entity_compare_before);
-
-       spin_unlock(&entity->rq->lock);
  }
/**
@@ -213,15 +211,14 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler 
*sched,
  void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
                             struct drm_sched_entity *entity)
  {
+       lockdep_assert_held(&entity->lock);
+       lockdep_assert_held(&rq->lock);
+
        if (!list_empty(&entity->list))
                return;
- spin_lock(&rq->lock);
-
        atomic_inc(rq->sched->score);
        list_add_tail(&entity->list, &rq->entities);
-
-       spin_unlock(&rq->lock);
  }
/**
@@ -235,6 +232,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
  void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
                                struct drm_sched_entity *entity)
  {
+       lockdep_assert_held(&entity->lock);
+
        if (list_empty(&entity->list))
                return;
@@ -247,7 +246,7 @@ void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
                rq->current_entity = NULL;
if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
-               drm_sched_rq_remove_fifo_locked(entity);
+               drm_sched_rq_remove_fifo_locked(entity, rq);
spin_unlock(&rq->lock);
  }
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 80198e6cf537..b21806d5a8eb 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -596,7 +596,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
  void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
                                struct drm_sched_entity *entity);
-void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, ktime_t ts);
+void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity,
+                                    struct drm_sched_rq *rq, ktime_t ts);
int drm_sched_entity_init(struct drm_sched_entity *entity,
                          enum drm_sched_priority priority,

Reply via email to