[PATCH 1/2] drm/sched: fix the bug of time out calculation(v3)

[Grodzovsky, Andrey]

What about removing

(kthread_should_park()) ? We decided it's useless as far as I remember.

Andrey
________________________________
From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> on behalf of Liu, Monk <Monk.Liu at amd.com>
Sent: 31 August 2021 20:24
To: Liu, Monk <Monk.Liu at amd.com>; amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>
Cc: dri-devel at lists.freedesktop.org <dri-devel at lists.freedesktop.org>
Subject: RE: [PATCH 1/2] drm/sched: fix the bug of time out calculation(v3)

[AMD Official Use Only]

Ping Christian, Andrey

Can we merge this patch first ? this is a standalone patch for the timer

Thanks

------------------------------------------
Monk Liu | Cloud-GPU Core team
------------------------------------------

-----Original Message-----
From: Monk Liu <Monk.Liu at amd.com>
Sent: Tuesday, August 31, 2021 6:36 PM
To: amd-gfx at lists.freedesktop.org
Cc: dri-devel at lists.freedesktop.org; Liu, Monk <Monk.Liu at amd.com>
Subject: [PATCH 1/2] drm/sched: fix the bug of time out calculation(v3)

issue:
in cleanup_job the cancle_delayed_work will cancel a TO timer even the its corresponding job is still running.

fix:
do not cancel the timer in cleanup_job, instead do the cancelling only when the heading job is signaled, and if there is a "next" job we start_timeout again.

v2:
further cleanup the logic, and do the TDR timer cancelling if the signaled job is the last one in its scheduler.

v3:
change the issue description
remove the cancel_delayed_work in the begining of the cleanup_job recover the implement of drm_sched_job_begin.

TODO:
1)introduce pause/resume scheduler in job_timeout to serial the handling of scheduler and job_timeout.
2)drop the bad job's del and insert in scheduler due to above serialization (no race issue anymore with the serialization)

tested-by: jingwen <jingwen.chen@@amd.com>
Signed-off-by: Monk Liu <Monk.Liu at amd.com>
---
 drivers/gpu/drm/scheduler/sched_main.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index a2a9536..ecf8140 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -676,13 +676,7 @@ drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)  {
         struct drm_sched_job *job, *next;

-       /*
-        * Don't destroy jobs while the timeout worker is running  OR thread
-        * is being parked and hence assumed to not touch pending_list
-        */
-       if ((sched->timeout != MAX_SCHEDULE_TIMEOUT &&
-           !cancel_delayed_work(&sched->work_tdr)) ||
-           kthread_should_park())
+       if (kthread_should_park())
                 return NULL;

         spin_lock(&sched->job_list_lock);
@@ -693,17 +687,21 @@ drm_sched_get_cleanup_job(struct drm_gpu_scheduler *sched)
         if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
                 /* remove job from pending_list */
                 list_del_init(&job->list);
+
+               /* cancel this job's TO timer */
+               cancel_delayed_work(&sched->work_tdr);
                 /* make the scheduled timestamp more accurate */
                 next = list_first_entry_or_null(&sched->pending_list,
                                                 typeof(*next), list);
-               if (next)
+
+               if (next) {
                         next->s_fence->scheduled.timestamp =
                                 job->s_fence->finished.timestamp;
-
+                       /* start TO timer for next job */
+                       drm_sched_start_timeout(sched);
+               }
         } else {
                 job = NULL;
-               /* queue timeout for next job */
-               drm_sched_start_timeout(sched);
         }

         spin_unlock(&sched->job_list_lock);
@@ -791,11 +789,8 @@ static int drm_sched_main(void *param)
                                           (entity = drm_sched_select_entity(sched))) ||
                                          kthread_should_stop());

-               if (cleanup_job) {
+               if (cleanup_job)
                         sched->ops->free_job(cleanup_job);
-                       /* queue timeout for next job */
-                       drm_sched_start_timeout(sched);
-               }

                 if (!entity)
                         continue;
--
2.7.4
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