On Thu, Nov 02, 2023 at 06:46:54PM -0400, Luben Tuikov wrote: > Eliminate drm_sched_run_job_queue_if_ready() and instead just call > drm_sched_run_job_queue() in drm_sched_free_job_work(). The problem is that > the former function uses drm_sched_select_entity() to determine if the > scheduler had an entity ready in one of its run-queues, and in the case of the > Round-Robin (RR) scheduling, the function drm_sched_rq_select_entity_rr() does > just that, selects the _next_ entity which is ready, sets up the run-queue and > completion and returns that entity. The FIFO scheduling algorithm is unaffected. > > Now, since drm_sched_run_job_work() also calls drm_sched_select_entity(), then > in the case of RR scheduling, that would result in calling select_entity() > twice, which may result in skipping a ready entity if more than one entity is > ready. This commit fixes this by eliminating the if_ready() variant. > Ah, yes I guess we both missed this. What about reviving the peek argument [1]? This would avoid unnecessary re-queues. Matt [1] https://patchwork.freedesktop.org/patch/562222/?series=121744&rev=7 > Signed-off-by: Luben Tuikov <ltuikov89@xxxxxxxxx> > --- > drivers/gpu/drm/scheduler/sched_main.c | 14 ++------------ > 1 file changed, 2 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c > index 98b2ad54fc7071..05816e7cae8c8b 100644 > --- a/drivers/gpu/drm/scheduler/sched_main.c > +++ b/drivers/gpu/drm/scheduler/sched_main.c > @@ -1040,16 +1040,6 @@ drm_sched_pick_best(struct drm_gpu_scheduler **sched_list, > } > EXPORT_SYMBOL(drm_sched_pick_best); > > -/** > - * 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 > * > @@ -1069,7 +1059,7 @@ static void drm_sched_free_job_work(struct work_struct *w) > sched->ops->free_job(cleanup_job); > > drm_sched_free_job_queue_if_done(sched); > - drm_sched_run_job_queue_if_ready(sched); > + drm_sched_run_job_queue(sched); > } > } > > @@ -1127,7 +1117,7 @@ static void drm_sched_run_job_work(struct work_struct *w) > } > > wake_up(&sched->job_scheduled); > - drm_sched_run_job_queue_if_ready(sched); > + drm_sched_run_job_queue(sched); > } > > /** > > base-commit: 6fd9487147c4f18ad77eea00bd8c9189eec74a3e > -- > 2.42.1 >
