This patch uses score to select a new drm scheduler for better loadbalance between multiple drm schedulers instead of num_jobs.
Below are test results after running amdgpu_test for ~10 times.
Before this patch:
sched_name num of many times it got schedule ========= ================================== sdma0 1463 sdma1 198 comp_1.0.1 280
After this patch:
sched_name num of many times it got schedule ========= ================================== sdma0 925 sdma1 928 comp_1.0.1 177 comp_1.1.1 44 comp_1.2.1 43 comp_1.3.1 44
Signed-off-by: Nirmoy Das nirmoy.das@amd.com --- drivers/gpu/drm/scheduler/sched_entity.c | 2 +- drivers/gpu/drm/scheduler/sched_main.c | 14 ++++++++------ include/drm/gpu_scheduler.h | 6 +++--- 3 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index c803e14eed91..146380118962 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -486,7 +486,7 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job, bool first;
trace_drm_sched_job(sched_job, entity); - atomic_inc(&entity->rq->sched->num_jobs); + atomic_inc(&entity->rq->sched->score); WRITE_ONCE(entity->last_user, current->group_leader); first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 8e731ed0d9d9..25a9e6911602 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -92,6 +92,7 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq, 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); } @@ -110,6 +111,7 @@ void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, if (list_empty(&entity->list)) return; spin_lock(&rq->lock); + atomic_dec(&rq->sched->score); list_del_init(&entity->list); if (rq->current_entity == entity) rq->current_entity = NULL; @@ -647,7 +649,7 @@ static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb) struct drm_gpu_scheduler *sched = s_fence->sched;
atomic_dec(&sched->hw_rq_count); - atomic_dec(&sched->num_jobs); + atomic_dec(&sched->score);
trace_drm_sched_process_job(s_fence);
@@ -712,7 +714,7 @@ drm_sched_pick_best(struct drm_gpu_scheduler **sched_list, { struct drm_gpu_scheduler *sched, *picked_sched = NULL; int i; - unsigned int min_jobs = UINT_MAX, num_jobs; + unsigned int min_score = UINT_MAX, num_score;
for (i = 0; i < num_sched_list; ++i) { sched = sched_list[i]; @@ -723,9 +725,9 @@ drm_sched_pick_best(struct drm_gpu_scheduler **sched_list, continue; }
- num_jobs = atomic_read(&sched->num_jobs); - if (num_jobs < min_jobs) { - min_jobs = num_jobs; + num_score = atomic_read(&sched->score); + if (num_score < min_score) { + min_score = num_score; picked_sched = sched; } } @@ -860,7 +862,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, spin_lock_init(&sched->job_list_lock); atomic_set(&sched->hw_rq_count, 0); INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout); - atomic_set(&sched->num_jobs, 0); + atomic_set(&sched->score, 0); atomic64_set(&sched->job_id_count, 0);
/* Each scheduler will run on a seperate kernel thread */ diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index a21b3b92135a..b9780ae9dd26 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -263,7 +263,7 @@ struct drm_sched_backend_ops { * @job_list_lock: lock to protect the ring_mirror_list. * @hang_limit: once the hangs by a job crosses this limit then it is marked * guilty and it will be considered for scheduling further. - * @num_jobs: the number of jobs in queue in the scheduler + * @score: score to help loadbalancer pick a idle sched * @ready: marks if the underlying HW is ready to work * @free_guilty: A hit to time out handler to free the guilty job. * @@ -284,8 +284,8 @@ struct drm_gpu_scheduler { struct list_head ring_mirror_list; spinlock_t job_list_lock; int hang_limit; - atomic_t num_jobs; - bool ready; + atomic_t score; + bool ready; bool free_guilty; };