On 31/10/2023 03:24, Matthew Brost wrote:
Rather than call free_job and run_job in same work item have a dedicated
work item for each. This aligns with the design and intended use of work
queues.
v2:
- Test for DMA_FENCE_FLAG_TIMESTAMP_BIT before setting
timestamp in free_job() work item (Danilo)
v3:
- Drop forward dec of drm_sched_select_entity (Boris)
- Return in drm_sched_run_job_work if entity NULL (Boris)
v4:
- Replace dequeue with peek and invert logic (Luben)
- Wrap to 100 lines (Luben)
- Update comments for *_queue / *_queue_if_ready functions (Luben)
v5:
- Drop peek argument, blindly reinit idle (Luben)
- s/drm_sched_free_job_queue_if_ready/drm_sched_free_job_queue_if_done (Luben)
- Update work_run_job & work_free_job kernel doc (Luben)
v6:
- Do not move drm_sched_select_entity in file (Luben)
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/scheduler/sched_main.c | 146 +++++++++++++++++--------
include/drm/gpu_scheduler.h | 4 +-
2 files changed, 101 insertions(+), 49 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index d1ae05bded15..3b1b2f8eafe8 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -265,6 +265,32 @@ static void drm_sched_run_job_queue(struct drm_gpu_scheduler *sched)
queue_work(sched->submit_wq, &sched->work_run_job);
}
+/**
+ * drm_sched_free_job_queue - enqueue free-job work
+ * @sched: scheduler instance
+ */
+static void drm_sched_free_job_queue(struct drm_gpu_scheduler *sched)
+{
+ if (!READ_ONCE(sched->pause_submit))
+ queue_work(sched->submit_wq, &sched->work_free_job);
+}
+
+/**
+ * drm_sched_free_job_queue_if_done - enqueue free-job work if ready
+ * @sched: scheduler instance
+ */
+static void drm_sched_free_job_queue_if_done(struct drm_gpu_scheduler *sched)
+{
+ struct drm_sched_job *job;
+
+ spin_lock(&sched->job_list_lock);
+ job = list_first_entry_or_null(&sched->pending_list,
+ struct drm_sched_job, list);
+ if (job && dma_fence_is_signaled(&job->s_fence->finished))
+ drm_sched_free_job_queue(sched);
+ spin_unlock(&sched->job_list_lock);
+}
+
/**
* drm_sched_job_done - complete a job
* @s_job: pointer to the job which is done
@@ -284,7 +310,7 @@ static void drm_sched_job_done(struct drm_sched_job *s_job, int result)
dma_fence_get(&s_fence->finished);
drm_sched_fence_finished(s_fence, result);
dma_fence_put(&s_fence->finished);
- drm_sched_run_job_queue(sched);
+ drm_sched_free_job_queue(sched);
}
/**
@@ -943,8 +969,10 @@ drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
typeof(*next), list);
if (next) {
- next->s_fence->scheduled.timestamp =
- dma_fence_timestamp(&job->s_fence->finished);
+ if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT,
+ &next->s_fence->scheduled.flags))
+ next->s_fence->scheduled.timestamp =
+ dma_fence_timestamp(&job->s_fence->finished);
/* start TO timer for next job */
drm_sched_start_timeout(sched);
}
@@ -994,7 +1022,40 @@ drm_sched_pick_best(struct drm_gpu_scheduler **sched_list,
EXPORT_SYMBOL(drm_sched_pick_best);
/**
- * drm_sched_run_job_work - main scheduler thread
+ * drm_sched_run_job_queue_if_ready - enqueue run-job work if ready
+ * @sched: scheduler instance
+ */
+static void drm_sched_run_job_queue_if_ready(struct drm_gpu_scheduler *sched)
+{
+ if (drm_sched_select_entity(sched))
+ drm_sched_run_job_queue(sched);
+}
+
+/**
+ * drm_sched_free_job_work - worker to call free_job
+ *
+ * @w: free job work
+ */
+static void drm_sched_free_job_work(struct work_struct *w)
+{
+ struct drm_gpu_scheduler *sched =
+ container_of(w, struct drm_gpu_scheduler, work_free_job);
+ struct drm_sched_job *cleanup_job;
+
+ if (READ_ONCE(sched->pause_submit))
+ return;
+
+ cleanup_job = drm_sched_get_cleanup_job(sched);
+ if (cleanup_job) {
+ sched->ops->free_job(cleanup_job);
+
+ drm_sched_free_job_queue_if_done(sched);
+ drm_sched_run_job_queue_if_ready(sched);
Are finished jobs now disturbing the round robin selection?
Every time this cleans up a job we get:
drm_sched_run_job_queue_if_ready
-> drm_sched_select_entity
-> drm_sched_rq_select_entity_rr
-> rq->current_entity bumped to next in list
So when the job run worker does:
entity = drm_sched_select_entity(sched);
It does not pick the same entity as before this patch? If so perhaps
drm_sched_run_job_queue_if_ready needs a "peek" helper which does not
modify any state.
Regards,
Tvrtko
+ }
+}
+
+/**
+ * drm_sched_run_job_work - worker to call run_job
*
* @w: run job work
*/
@@ -1003,65 +1064,51 @@ static void drm_sched_run_job_work(struct work_struct *w)
struct drm_gpu_scheduler *sched =
container_of(w, struct drm_gpu_scheduler, work_run_job);
struct drm_sched_entity *entity;
- struct drm_sched_job *cleanup_job;
+ struct dma_fence *fence;
+ struct drm_sched_fence *s_fence;
+ struct drm_sched_job *sched_job;
int r;
if (READ_ONCE(sched->pause_submit))
return;
- cleanup_job = drm_sched_get_cleanup_job(sched);
entity = drm_sched_select_entity(sched);
+ if (!entity)
+ return;
- if (!entity && !cleanup_job)
+ sched_job = drm_sched_entity_pop_job(entity);
+ if (!sched_job) {
+ complete_all(&entity->entity_idle);
return; /* No more work */
+ }
- if (cleanup_job)
- sched->ops->free_job(cleanup_job);
-
- if (entity) {
- struct dma_fence *fence;
- struct drm_sched_fence *s_fence;
- struct drm_sched_job *sched_job;
-
- sched_job = drm_sched_entity_pop_job(entity);
- if (!sched_job) {
- complete_all(&entity->entity_idle);
- if (!cleanup_job)
- return; /* No more work */
- goto again;
- }
-
- s_fence = sched_job->s_fence;
-
- atomic_inc(&sched->hw_rq_count);
- drm_sched_job_begin(sched_job);
+ s_fence = sched_job->s_fence;
- trace_drm_run_job(sched_job, entity);
- fence = sched->ops->run_job(sched_job);
- complete_all(&entity->entity_idle);
- drm_sched_fence_scheduled(s_fence, fence);
+ atomic_inc(&sched->hw_rq_count);
+ drm_sched_job_begin(sched_job);
- if (!IS_ERR_OR_NULL(fence)) {
- /* Drop for original kref_init of the fence */
- dma_fence_put(fence);
+ trace_drm_run_job(sched_job, entity);
+ fence = sched->ops->run_job(sched_job);
+ complete_all(&entity->entity_idle);
+ drm_sched_fence_scheduled(s_fence, fence);
- r = dma_fence_add_callback(fence, &sched_job->cb,
- drm_sched_job_done_cb);
- if (r == -ENOENT)
- drm_sched_job_done(sched_job, fence->error);
- else if (r)
- DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n",
- r);
- } else {
- drm_sched_job_done(sched_job, IS_ERR(fence) ?
- PTR_ERR(fence) : 0);
- }
+ if (!IS_ERR_OR_NULL(fence)) {
+ /* Drop for original kref_init of the fence */
+ dma_fence_put(fence);
- wake_up(&sched->job_scheduled);
+ r = dma_fence_add_callback(fence, &sched_job->cb,
+ drm_sched_job_done_cb);
+ if (r == -ENOENT)
+ drm_sched_job_done(sched_job, fence->error);
+ else if (r)
+ DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n", r);
+ } else {
+ drm_sched_job_done(sched_job, IS_ERR(fence) ?
+ PTR_ERR(fence) : 0);
}
-again:
- drm_sched_run_job_queue(sched);
+ wake_up(&sched->job_scheduled);
+ drm_sched_run_job_queue_if_ready(sched);
}
/**
@@ -1145,6 +1192,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched,
atomic_set(&sched->hw_rq_count, 0);
INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout);
INIT_WORK(&sched->work_run_job, drm_sched_run_job_work);
+ INIT_WORK(&sched->work_free_job, drm_sched_free_job_work);
atomic_set(&sched->_score, 0);
atomic64_set(&sched->job_id_count, 0);
sched->pause_submit = false;
@@ -1274,6 +1322,7 @@ void drm_sched_wqueue_stop(struct drm_gpu_scheduler *sched)
{
WRITE_ONCE(sched->pause_submit, true);
cancel_work_sync(&sched->work_run_job);
+ cancel_work_sync(&sched->work_free_job);
}
EXPORT_SYMBOL(drm_sched_wqueue_stop);
@@ -1286,5 +1335,6 @@ void drm_sched_wqueue_start(struct drm_gpu_scheduler *sched)
{
WRITE_ONCE(sched->pause_submit, false);
queue_work(sched->submit_wq, &sched->work_run_job);
+ queue_work(sched->submit_wq, &sched->work_free_job);
}
EXPORT_SYMBOL(drm_sched_wqueue_start);
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index e0e7c4eb57d9..677ba96759ab 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -479,9 +479,10 @@ struct drm_sched_backend_ops {
* finished.
* @hw_rq_count: the number of jobs currently in the hardware queue.
* @job_id_count: used to assign unique id to the each job.
- * @submit_wq: workqueue used to queue @work_run_job
+ * @submit_wq: workqueue used to queue @work_run_job and @work_free_job
* @timeout_wq: workqueue used to queue @work_tdr
* @work_run_job: work which calls run_job op of each scheduler.
+ * @work_free_job: work which calls free_job op of each scheduler.
* @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the
* timeout interval is over.
* @pending_list: the list of jobs which are currently in the job queue.
@@ -511,6 +512,7 @@ struct drm_gpu_scheduler {
struct workqueue_struct *submit_wq;
struct workqueue_struct *timeout_wq;
struct work_struct work_run_job;
+ struct work_struct work_free_job;
struct delayed_work work_tdr;
struct list_head pending_list;
spinlock_t job_list_lock;
