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

[Grodzovsky, Andrey]

On 7/3/19 10:32 AM, Lucas Stach wrote:
> 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.


Not sure about this as you patch only concerns use case when cleaning 
unfinished job's for entity being destroyed.

Andrey


>
> Regards,
> Lucas