[PATCH v3 2/2] drm/sched: Rework HW fence processing.
Zhou, David(ChunMing)
David1.Zhou at amd.com
Tue Dec 11 02:45:53 UTC 2018
I don't think adding cb to sched job would work as soon as their lifetime is different with fence.
Unless you make the sched job reference, otherwise we will get trouble sooner or later.
-David
> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
> Andrey Grodzovsky
> Sent: Tuesday, December 11, 2018 5:44 AM
> To: dri-devel at lists.freedesktop.org; amd-gfx at lists.freedesktop.org;
> ckoenig.leichtzumerken at gmail.com; eric at anholt.net;
> etnaviv at lists.freedesktop.org
> Cc: Zhou, David(ChunMing) <David1.Zhou at amd.com>; Liu, Monk
> <Monk.Liu at amd.com>; Grodzovsky, Andrey
> <Andrey.Grodzovsky at amd.com>
> Subject: [PATCH v3 2/2] drm/sched: Rework HW fence processing.
>
> Expedite job deletion from ring mirror list to the HW fence signal callback
> instead from finish_work, together with waiting for all such fences to signal in
> drm_sched_stop we garantee that already signaled job will not be processed
> twice.
> Remove the sched finish fence callback and just submit finish_work directly
> from the HW fence callback.
>
> v2: Fix comments.
>
> v3: Attach hw fence cb to sched_job
>
> Suggested-by: Christian Koenig <Christian.Koenig at amd.com>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
> ---
> drivers/gpu/drm/scheduler/sched_main.c | 58 ++++++++++++++++----------
> --------
> include/drm/gpu_scheduler.h | 6 ++--
> 2 files changed, 30 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
> b/drivers/gpu/drm/scheduler/sched_main.c
> index cdf95e2..f0c1f32 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -284,8 +284,6 @@ static void drm_sched_job_finish(struct work_struct
> *work)
> cancel_delayed_work_sync(&sched->work_tdr);
>
> spin_lock_irqsave(&sched->job_list_lock, flags);
> - /* remove job from ring_mirror_list */
> - list_del_init(&s_job->node);
> /* queue TDR for next job */
> drm_sched_start_timeout(sched);
> spin_unlock_irqrestore(&sched->job_list_lock, flags); @@ -293,22
> +291,11 @@ static void drm_sched_job_finish(struct work_struct *work)
> sched->ops->free_job(s_job);
> }
>
> -static void drm_sched_job_finish_cb(struct dma_fence *f,
> - struct dma_fence_cb *cb)
> -{
> - struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
> - finish_cb);
> - schedule_work(&job->finish_work);
> -}
> -
> static void drm_sched_job_begin(struct drm_sched_job *s_job) {
> struct drm_gpu_scheduler *sched = s_job->sched;
> unsigned long flags;
>
> - dma_fence_add_callback(&s_job->s_fence->finished, &s_job-
> >finish_cb,
> - drm_sched_job_finish_cb);
> -
> spin_lock_irqsave(&sched->job_list_lock, flags);
> list_add_tail(&s_job->node, &sched->ring_mirror_list);
> drm_sched_start_timeout(sched);
> @@ -359,12 +346,11 @@ void drm_sched_stop(struct drm_gpu_scheduler
> *sched, struct drm_sched_job *bad,
> list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node)
> {
> if (s_job->s_fence->parent &&
> dma_fence_remove_callback(s_job->s_fence->parent,
> - &s_job->s_fence->cb)) {
> + &s_job->cb)) {
> dma_fence_put(s_job->s_fence->parent);
> s_job->s_fence->parent = NULL;
> atomic_dec(&sched->hw_rq_count);
> - }
> - else {
> + } else {
> /* TODO Is it get/put neccessey here ? */
> dma_fence_get(&s_job->s_fence->finished);
> list_add(&s_job->finish_node, &wait_list); @@ -
> 417,31 +403,34 @@ EXPORT_SYMBOL(drm_sched_stop); void
> drm_sched_start(struct drm_gpu_scheduler *sched, bool unpark_only) {
> struct drm_sched_job *s_job, *tmp;
> - unsigned long flags;
> int r;
>
> if (unpark_only)
> goto unpark;
>
> - spin_lock_irqsave(&sched->job_list_lock, flags);
> + /*
> + * Locking the list is not required here as the sched thread is parked
> + * so no new jobs are being pushed in to HW and in drm_sched_stop
> we
> + * flushed all the jobs who were still in mirror list but who already
> + * signaled and removed them self from the list. Also concurrent
> + * GPU recovers can't run in parallel.
> + */
> list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list,
> node) {
> - struct drm_sched_fence *s_fence = s_job->s_fence;
> struct dma_fence *fence = s_job->s_fence->parent;
>
> if (fence) {
> - r = dma_fence_add_callback(fence, &s_fence->cb,
> + r = dma_fence_add_callback(fence, &s_job->cb,
> drm_sched_process_job);
> if (r == -ENOENT)
> - drm_sched_process_job(fence, &s_fence-
> >cb);
> + drm_sched_process_job(fence, &s_job->cb);
> else if (r)
> DRM_ERROR("fence add callback failed
> (%d)\n",
> r);
> } else
> - drm_sched_process_job(NULL, &s_fence->cb);
> + drm_sched_process_job(NULL, &s_job->cb);
> }
>
> drm_sched_start_timeout(sched);
> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
>
> unpark:
> kthread_unpark(sched->thread);
> @@ -590,18 +579,27 @@ drm_sched_select_entity(struct
> drm_gpu_scheduler *sched)
> */
> static void drm_sched_process_job(struct dma_fence *f, struct
> dma_fence_cb *cb) {
> - struct drm_sched_fence *s_fence =
> - container_of(cb, struct drm_sched_fence, cb);
> + struct drm_sched_job *s_job = container_of(cb, struct
> drm_sched_job, cb);
> + struct drm_sched_fence *s_fence = s_job->s_fence;
> struct drm_gpu_scheduler *sched = s_fence->sched;
> + unsigned long flags;
> +
> + cancel_delayed_work(&sched->work_tdr);
>
> - dma_fence_get(&s_fence->finished);
> atomic_dec(&sched->hw_rq_count);
> atomic_dec(&sched->num_jobs);
> +
> + spin_lock_irqsave(&sched->job_list_lock, flags);
> + /* remove job from ring_mirror_list */
> + list_del_init(&s_job->node);
> + spin_unlock_irqrestore(&sched->job_list_lock, flags);
> +
> drm_sched_fence_finished(s_fence);
>
> trace_drm_sched_process_job(s_fence);
> - dma_fence_put(&s_fence->finished);
> wake_up_interruptible(&sched->wake_up_worker);
> +
> + schedule_work(&s_job->finish_work);
> }
>
> /**
> @@ -664,16 +662,16 @@ static int drm_sched_main(void *param)
>
> if (fence) {
> s_fence->parent = dma_fence_get(fence);
> - r = dma_fence_add_callback(fence, &s_fence->cb,
> + r = dma_fence_add_callback(fence, &sched_job->cb,
> drm_sched_process_job);
> if (r == -ENOENT)
> - drm_sched_process_job(fence, &s_fence-
> >cb);
> + drm_sched_process_job(fence, &sched_job-
> >cb);
> else if (r)
> DRM_ERROR("fence add callback failed
> (%d)\n",
> r);
> dma_fence_put(fence);
> } else
> - drm_sched_process_job(NULL, &s_fence->cb);
> + drm_sched_process_job(NULL, &sched_job->cb);
>
> wake_up(&sched->job_scheduled);
> }
> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> index c94b592..f29aa1c 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -138,10 +138,6 @@ struct drm_sched_fence {
> struct dma_fence finished;
>
> /**
> - * @cb: the callback for the parent fence below.
> - */
> - struct dma_fence_cb cb;
> - /**
> * @parent: the fence returned by &drm_sched_backend_ops.run_job
> * when scheduling the job on hardware. We signal the
> * &drm_sched_fence.finished fence once parent is signalled.
> @@ -182,6 +178,7 @@ struct drm_sched_fence
> *to_drm_sched_fence(struct dma_fence *f);
> * be scheduled further.
> * @s_priority: the priority of the job.
> * @entity: the entity to which this job belongs.
> + * @cb: the callback for the parent fence in s_fence.
> *
> * A job is created by the driver using drm_sched_job_init(), and
> * should call drm_sched_entity_push_job() once it wants the scheduler
> @@ -199,6 +196,7 @@ struct drm_sched_job {
> atomic_t karma;
> enum drm_sched_priority s_priority;
> struct drm_sched_entity *entity;
> + struct dma_fence_cb cb;
> };
>
> static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
> --
> 2.7.4
>
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