Jobs submitted in an entity should execute in the order those jobs are submitted. We make sure that by checking entity->job_queue in drm_sched_entity_select_rq() so that we don't loadbalance jobs within an entity.
But because we update entity->job_queue later in drm_sched_entity_push_job(), there remains a open window when it is possibe that entity->rq might get updated by drm_sched_entity_select_rq() which should not be allowed. Changes in this part also improves job distribution. Below are test results after running amdgpu_test from mesa drm Before this patch: sched_name num of many times it got scheduled ========= ================================== sdma0 314 sdma1 32 comp_1.0.0 56 comp_1.1.0 0 comp_1.1.1 0 comp_1.2.0 0 comp_1.2.1 0 comp_1.3.0 0 comp_1.3.1 0 After this patch: sched_name num of many times it got scheduled ========= ================================== sdma1 243 sdma0 164 comp_1.0.1 14 comp_1.1.0 11 comp_1.1.1 10 comp_1.2.0 15 comp_1.2.1 14 comp_1.3.0 10 comp_1.3.1 10 Fixes: 35e160e781a048 (drm/scheduler: change entities rq even earlier) Signed-off-by: Nirmoy Das <[email protected]> Reported-by: Pierre-Eric Pelloux-Prayer <[email protected]> --- drivers/gpu/drm/scheduler/sched_entity.c | 9 +++++++-- drivers/gpu/drm/scheduler/sched_main.c | 1 + include/drm/gpu_scheduler.h | 1 + 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 2e3a058fc239..8414e084b6ac 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -67,6 +67,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, entity->priority = priority; entity->sched_list = num_sched_list > 1 ? sched_list : NULL; entity->last_scheduled = NULL; + entity->loadbalance_on = true; if(num_sched_list) entity->rq = &sched_list[0]->sched_rq[entity->priority]; @@ -447,6 +448,9 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished); spsc_queue_pop(&entity->job_queue); + if (!spsc_queue_count(&entity->job_queue)) + entity->loadbalance_on = true; + return sched_job; } @@ -463,7 +467,8 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) struct dma_fence *fence; struct drm_sched_rq *rq; - if (spsc_queue_count(&entity->job_queue) || entity->num_sched_list <= 1) + atomic_inc(&entity->rq->sched->num_jobs); + if ((entity->num_sched_list <= 1) || !entity->loadbalance_on) return; fence = READ_ONCE(entity->last_scheduled); @@ -477,6 +482,7 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) entity->rq = rq; } + entity->loadbalance_on = false; spin_unlock(&entity->rq_lock); } @@ -498,7 +504,6 @@ 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); 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 3fad5876a13f..00fdc350134e 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -562,6 +562,7 @@ int drm_sched_job_init(struct drm_sched_job *job, return -ENOENT; sched = entity->rq->sched; + atomic_inc(&entity->rq->sched->num_jobs); job->sched = sched; job->entity = entity; diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 96a1a1b7526e..a5190869d323 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -97,6 +97,7 @@ struct drm_sched_entity { struct dma_fence *last_scheduled; struct task_struct *last_user; bool stopped; + bool loadbalance_on; struct completion entity_idle; }; -- 2.24.1 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
