[PATCH 1/2] drm/sched: fix the bug of time out calculation(v4)

[Alex Deucher]

On Wed, Sep 1, 2021 at 2:50 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 01.09.21 um 02:46 schrieb Monk Liu:
> > 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.
> >
> > v4:
> > remove the kthread_should_park() checking in cleanup_job routine,
> > we should cleanup the signaled job asap
> >
> > 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>
>
> Reviewed-by: Christian König <christian.koenig at amd.com>
>

Are you planning to push this to drm-misc?

Alex


> > ---
> >   drivers/gpu/drm/scheduler/sched_main.c | 26 +++++++++-----------------
> >   1 file changed, 9 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> > index a2a9536..3e0bbc7 100644
> > --- a/drivers/gpu/drm/scheduler/sched_main.c
> > +++ b/drivers/gpu/drm/scheduler/sched_main.c
> > @@ -676,15 +676,6 @@ 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())
> > -             return NULL;
> > -
> >       spin_lock(&sched->job_list_lock);
> >
> >       job = list_first_entry_or_null(&sched->pending_list,
> > @@ -693,17 +684,21 @@ 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 +786,8 @@ 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;
>