[PATCH] drm/scheduler: put killed job cleanup to worker

[Lucas Stach]

Am Mittwoch, den 03.07.2019, 14:23 +0000 schrieb Grodzovsky, Andrey:
> On 7/3/19 6:28 AM, Lucas Stach wrote:
> > drm_sched_entity_kill_jobs_cb() is called right from the last scheduled
> > job finished fence signaling. As this might happen from IRQ context we
> > now end up calling the GPU driver free_job callback in IRQ context, while
> > all other paths call it from normal process context.
> > 
> > Etnaviv in particular calls core kernel functions that are only valid to
> > be called from process context when freeing the job. Other drivers might
> > have similar issues, but I did not validate this. Fix this by punting
> > the cleanup work into a work item, so the driver expectations are met.
> > 
> > > > Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> > ---
> >   drivers/gpu/drm/scheduler/sched_entity.c | 28 ++++++++++++++----------
> >   1 file changed, 17 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
> > index 35ddbec1375a..ba4eb66784b9 100644
> > --- a/drivers/gpu/drm/scheduler/sched_entity.c
> > +++ b/drivers/gpu/drm/scheduler/sched_entity.c
> > @@ -202,23 +202,23 @@ long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
> >   }
> >   EXPORT_SYMBOL(drm_sched_entity_flush);
> >   
> > -/**
> > - * drm_sched_entity_kill_jobs - helper for drm_sched_entity_kill_jobs
> > - *
> > - * @f: signaled fence
> > - * @cb: our callback structure
> > - *
> > - * Signal the scheduler finished fence when the entity in question is killed.
> > - */
> > +static void drm_sched_entity_kill_work(struct work_struct *work)
> > +{
> > > > +	struct drm_sched_job *job = container_of(work, struct drm_sched_job,
> > > > +						 finish_work);
> > +
> > > > +	drm_sched_fence_finished(job->s_fence);
> > > > +	WARN_ON(job->s_fence->parent);
> > > > +	job->sched->ops->free_job(job);
> > +}
> > +
> >   static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
> > > >   					  struct dma_fence_cb *cb)
> >   {
> > > >   	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
> > > >   						 finish_cb);
> >   
> > > > -	drm_sched_fence_finished(job->s_fence);
> > > > -	WARN_ON(job->s_fence->parent);
> > > > -	job->sched->ops->free_job(job);
> > > > +	schedule_work(&job->finish_work);
> >   }
> >   
> >   /**
> > @@ -240,6 +240,12 @@ static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
> > > >   		drm_sched_fence_scheduled(s_fence);
> > > >   		dma_fence_set_error(&s_fence->finished, -ESRCH);
> >   
> > > > +		/*
> > > > +		 * Replace regular finish work function with one that just
> > > > +		 * kills the job.
> > > > +		 */
> > +		job->finish_work.func = drm_sched_entity_kill_work;
> 
> 
> I rechecked the latest code and finish_work was removed in ffae3e5 
> 'drm/scheduler: rework job destruction'

Aw, thanks. Seems this patch was stuck for a bit too long in my
outgoing queue. I've just checked the commit you pointed out, it should
also fix the issue that this patch was trying to fix.

Regards,
Lucas