Re: [PATCH 1/2] drm/sched: Refactor ring mirror list handling.

Christian König
2018-12-06T18:33:53Z

Am 06.12.18 um 18:41 schrieb Andrey Grodzovsky:
> Decauple sched threads stop and start and ring mirror
> list handling from the policy of what to do about the
> guilty jobs.
> When stoppping the sched thread and detaching sched fences
> from non signaled HW fenes wait for all signaled HW fences
> to complete before rerunning the jobs.
>
> Suggested-by: Christian Koenig <Christian.Koenig@amd.com>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>

Just briefly skimmed over this, but it looks exactly like what I had in
mind.

Need to give that a more detailed thought tomorrow,
Christian.

> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 17 +++---
> drivers/gpu/drm/etnaviv/etnaviv_sched.c | 8 +--
> drivers/gpu/drm/scheduler/sched_main.c | 86 +++++++++++++++++++-----------
> drivers/gpu/drm/v3d/v3d_sched.c | 11 ++--
> include/drm/gpu_scheduler.h | 10 ++--
> 5 files changed, 83 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index ef36cc5..42111d5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3292,17 +3292,16 @@ static int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
> /* block all schedulers and reset given job's ring */
> for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
> struct amdgpu_ring *ring = adev->rings[i];
> + bool park_only = job && job->base.sched != &ring->sched;
>
> if (!ring || !ring->sched.thread)
> continue;
>
> - kthread_park(ring->sched.thread);
> + drm_sched_stop(&ring->sched, job ? &job->base : NULL, park_only);
>
> - if (job && job->base.sched != &ring->sched)
> + if (park_only)
> continue;
>
> - drm_sched_hw_job_reset(&ring->sched, job ? &job->base : NULL);
> -
> /* after all hw jobs are reset, hw fence is meaningless, so force_completion */
> amdgpu_fence_driver_force_completion(ring);
> }
> @@ -3445,6 +3444,7 @@ static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
> struct amdgpu_job *job)
> {
> int i;
> + bool unpark_only;
>
> for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
> struct amdgpu_ring *ring = adev->rings[i];
> @@ -3456,10 +3456,13 @@ static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
> * or all rings (in the case @job is NULL)
> * after above amdgpu_reset accomplished
> */
> - if ((!job || job->base.sched == &ring->sched) && !adev->asic_reset_res)
> - drm_sched_job_recovery(&ring->sched);
> + unpark_only = (job && job->base.sched != &ring->sched) ||
> + adev->asic_reset_res;
> +
> + if (!unpark_only)
> + drm_sched_resubmit_jobs(&ring->sched);
>
> - kthread_unpark(ring->sched.thread);
> + drm_sched_start(&ring->sched, unpark_only);
> }
>
> if (!amdgpu_device_has_dc_support(adev)) {
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> index 49a6763..fab3b51 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
> @@ -109,16 +109,16 @@ static void etnaviv_sched_timedout_job(struct drm_sched_job *sched_job)
> }
>
> /* block scheduler */
> - kthread_park(gpu->sched.thread);
> - drm_sched_hw_job_reset(&gpu->sched, sched_job);
> + drm_sched_stop(&gpu->sched, sched_job, false);
>
> /* get the GPU back into the init state */
> etnaviv_core_dump(gpu);
> etnaviv_gpu_recover_hang(gpu);
>
> + drm_sched_resubmit_jobs(&gpu->sched);
> +
> /* restart scheduler after GPU is usable again */
> - drm_sched_job_recovery(&gpu->sched);
> - kthread_unpark(gpu->sched.thread);
> + drm_sched_start(&gpu->sched);
> }
>
> static void etnaviv_sched_free_job(struct drm_sched_job *sched_job)
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index dbb6906..8fb7f86 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -60,8 +60,6 @@
>
> static void drm_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb);
>
> -static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job);
> -
> /**
> * drm_sched_rq_init - initialize a given run queue struct
> *
> @@ -342,13 +340,21 @@ static void drm_sched_job_timedout(struct work_struct *work)
> * @bad: bad scheduler job
> *
> */
> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
> +void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad,
> + bool park_only)
> {
> struct drm_sched_job *s_job;
> struct drm_sched_entity *entity, *tmp;
> unsigned long flags;
> + struct list_head wait_list;
> int i;
>
> + kthread_park(sched->thread);
> + if (park_only)
> + return;
> +
> + INIT_LIST_HEAD(&wait_list);
> +
> spin_lock_irqsave(&sched->job_list_lock, flags);
> list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node) {
> if (s_job->s_fence->parent &&
> @@ -358,9 +364,24 @@ void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_jo
> s_job->s_fence->parent = NULL;
> atomic_dec(&sched->hw_rq_count);
> }
> + else {
> + /* TODO Is it get/put neccessey here ? */
> + dma_fence_get(&s_job->s_fence->finished);
> + list_add(&s_job->finish_node, &wait_list);
> + }
> }
> spin_unlock_irqrestore(&sched->job_list_lock, flags);
>
> + /*
> + * Verify all the signaled jobs in mirror list are removed from the ring
> + * We rely on the fact that any finish_work in progress will wait for this
> + * handler to complete before releasing all of the jobs we iterate.
> + */
> + list_for_each_entry(s_job, &wait_list, finish_node) {
> + dma_fence_wait(&s_job->s_fence->finished, false);
> + dma_fence_put(&s_job->s_fence->finished);
> + }
> +
> if (bad && bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
> atomic_inc(&bad->karma);
> /* don't increase @bad's karma if it's from KERNEL RQ,
> @@ -385,7 +406,7 @@ void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched, struct drm_sched_jo
> }
> }
> }
> -EXPORT_SYMBOL(drm_sched_hw_job_reset);
> +EXPORT_SYMBOL(drm_sched_stop);
>
> /**
> * drm_sched_job_recovery - recover jobs after a reset
> @@ -393,14 +414,17 @@ EXPORT_SYMBOL(drm_sched_hw_job_reset);
> * @sched: scheduler instance
> *
> */
> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool unpark_only)
> {
> struct drm_sched_job *s_job, *tmp;
> bool found_guilty = false;
> unsigned long flags;
> int r;
>
> - spin_lock_irqsave(&sched->job_list_lock, flags);
> + if (unpark_only)
> + goto unpark;
> +
> + spin_lock_irqsave(&sched->job_list_lock, flags);
> 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;
> @@ -414,12 +438,9 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
> if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
> dma_fence_set_error(&s_fence->finished, -ECANCELED);
>
> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
> - fence = sched->ops->run_job(s_job);
> - atomic_inc(&sched->hw_rq_count);
>
> + fence = s_job->s_fence->parent;
> if (fence) {
> - s_fence->parent = dma_fence_get(fence);
> r = dma_fence_add_callback(fence, &s_fence->cb,
> drm_sched_process_job);
> if (r == -ENOENT)
> @@ -427,18 +448,35 @@ void drm_sched_job_recovery(struct drm_gpu_scheduler *sched)
> else if (r)
> DRM_ERROR("fence add callback failed (%d)\n",
> r);
> - dma_fence_put(fence);
> - } else {
> - if (s_fence->finished.error < 0)
> - drm_sched_expel_job_unlocked(s_job);
> + } else
> drm_sched_process_job(NULL, &s_fence->cb);
> - }
> - spin_lock_irqsave(&sched->job_list_lock, flags);
> }
> +
> drm_sched_start_timeout(sched);
> spin_unlock_irqrestore(&sched->job_list_lock, flags);
> +
> +unpark:
> + kthread_unpark(sched->thread);
> }
> -EXPORT_SYMBOL(drm_sched_job_recovery);
> +EXPORT_SYMBOL(drm_sched_start);
> +
> +/**
> + * drm_sched_resubmit_jobs - helper to relunch job from mirror ring list
> + *
> + * @sched: scheduler instance
> + *
> + */
> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
> +{
> + struct drm_sched_job *s_job, *tmp;
> +
> + /*TODO DO we need spinlock here ? */
> + list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
> + s_job->s_fence->parent = sched->ops->run_job(s_job);
> + atomic_inc(&sched->hw_rq_count);
> + }
> +}
> +EXPORT_SYMBOL(drm_sched_resubmit_jobs);
>
> /**
> * drm_sched_job_init - init a scheduler job
> @@ -634,26 +672,14 @@ static int drm_sched_main(void *param)
> DRM_ERROR("fence add callback failed (%d)\n",
> r);
> dma_fence_put(fence);
> - } else {
> - if (s_fence->finished.error < 0)
> - drm_sched_expel_job_unlocked(sched_job);
> + } else
> drm_sched_process_job(NULL, &s_fence->cb);
> - }
>
> wake_up(&sched->job_scheduled);
> }
> return 0;
> }
>
> -static void drm_sched_expel_job_unlocked(struct drm_sched_job *s_job)
> -{
> - struct drm_gpu_scheduler *sched = s_job->sched;
> -
> - spin_lock(&sched->job_list_lock);
> - list_del_init(&s_job->node);
> - spin_unlock(&sched->job_list_lock);
> -}
> -
> /**
> * drm_sched_init - Init a gpu scheduler instance
> *
> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
> index 445b2ef..f99346a 100644
> --- a/drivers/gpu/drm/v3d/v3d_sched.c
> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
> @@ -178,18 +178,19 @@ v3d_job_timedout(struct drm_sched_job *sched_job)
> for (q = 0; q < V3D_MAX_QUEUES; q++) {
> struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
>
> - kthread_park(sched->thread);
> - drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
> - sched_job : NULL));
> + drm_sched_stop(sched, (sched_job->sched == sched ?
> + sched_job : NULL), false);
> }
>
> /* get the GPU back into the init state */
> v3d_reset(v3d);
>
> + for (q = 0; q < V3D_MAX_QUEUES; q++)
> + drm_sched_resubmit_jobs(sched_job->sched);
> +
> /* Unblock schedulers and restart their jobs. */
> for (q = 0; q < V3D_MAX_QUEUES; q++) {
> - drm_sched_job_recovery(&v3d->queue[q].sched);
> - kthread_unpark(v3d->queue[q].sched.thread);
> + drm_sched_start(&v3d->queue[q].sched, false);
> }
>
> mutex_unlock(&v3d->reset_lock);
> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> index 47e1979..c94b592 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -175,6 +175,7 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
> * finished to remove the job from the
> * @drm_gpu_scheduler.ring_mirror_list.
> * @node: used to append this struct to the @drm_gpu_scheduler.ring_mirror_list.
> + * @finish_node: used in a list to wait on before resetting the scheduler
> * @id: a unique id assigned to each job scheduled on the scheduler.
> * @karma: increment on every hang caused by this job. If this exceeds the hang
> * limit of the scheduler then the job is marked guilty and will not
> @@ -193,6 +194,7 @@ struct drm_sched_job {
> struct dma_fence_cb finish_cb;
> struct work_struct finish_work;
> struct list_head node;
> + struct list_head finish_node;
> uint64_t id;
> atomic_t karma;
> enum drm_sched_priority s_priority;
> @@ -298,9 +300,11 @@ int drm_sched_job_init(struct drm_sched_job *job,
> void *owner);
> void drm_sched_job_cleanup(struct drm_sched_job *job);
> void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
> -void drm_sched_hw_job_reset(struct drm_gpu_scheduler *sched,
> - struct drm_sched_job *job);
> -void drm_sched_job_recovery(struct drm_gpu_scheduler *sched);
> +void drm_sched_stop(struct drm_gpu_scheduler *sched,
> + struct drm_sched_job *job,
> + bool park_only);
> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool unpark_only);
> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
> bool drm_sched_dependency_optimized(struct dma_fence* fence,
> struct drm_sched_entity *entity);
> void drm_sched_fault(struct drm_gpu_scheduler *sched);

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