[PATCH v5 1/2] drm/sched: Refactor ring mirror list handling.
Koenig, Christian
Christian.Koenig at amd.com
Thu Jan 3 08:54:13 UTC 2019
Am 21.12.18 um 21:36 schrieb Grodzovsky, Andrey:
>
> On 12/21/2018 01:37 PM, Christian König wrote:
>> Am 20.12.18 um 20:23 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.
>>>
>>> v2: Fix resubmission of guilty job into HW after refactoring.
>>>
>>> v4:
>>> Full restart for all the jobs, not only from guilty ring.
>>> Extract karma increase into standalone function.
>>>
>>> v5:
>>> Rework waiting for signaled jobs without relying on the job
>>> struct itself as those might already be freed for non 'guilty'
>>> job's schedulers.
>>> Expose karma increase to drivers.
>>>
>>> Suggested-by: Christian Koenig <Christian.Koenig at amd.com>
>>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>>> ---
>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 18 +--
>>> drivers/gpu/drm/etnaviv/etnaviv_sched.c | 11 +-
>>> drivers/gpu/drm/scheduler/sched_main.c | 188
>>> +++++++++++++++++++----------
>>> drivers/gpu/drm/v3d/v3d_sched.c | 12 +-
>>> include/drm/gpu_scheduler.h | 10 +-
>>> 5 files changed, 151 insertions(+), 88 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> index 8a078f4..a4bd2d3 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -3298,12 +3298,10 @@ static int
>>> amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
>>> if (!ring || !ring->sched.thread)
>>> continue;
>>> - kthread_park(ring->sched.thread);
>>> + drm_sched_stop(&ring->sched, job ? &job->base : NULL);
>>> - if (job && job->base.sched != &ring->sched)
>>> - continue;
>>> -
>>> - drm_sched_hw_job_reset(&ring->sched, job ? &job->base : NULL);
>>> + if(job)
>>> + drm_sched_increase_karma(&job->base);
>> Since we dropped the "job && job->base.sched != &ring->sched" check
>> above this will now increase the jobs karma multiple times.
>>
>> Maybe just move that outside of the loop.
>>
>>> /* after all hw jobs are reset, hw fence is meaningless,
>>> so force_completion */
>>> amdgpu_fence_driver_force_completion(ring);
>>> @@ -3454,14 +3452,10 @@ static void
>>> amdgpu_device_post_asic_reset(struct amdgpu_device *adev,
>>> if (!ring || !ring->sched.thread)
>>> continue;
>>> - /* only need recovery sched of the given job's ring
>>> - * 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);
>>> + if (!adev->asic_reset_res)
>>> + drm_sched_resubmit_jobs(&ring->sched);
>>> - kthread_unpark(ring->sched.thread);
>>> + drm_sched_start(&ring->sched, !adev->asic_reset_res);
>>> }
>>> 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..6f1268f 100644
>>> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> @@ -109,16 +109,19 @@ 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);
>>> +
>>> + if(sched_job)
>>> + drm_sched_increase_karma(sched_job);
>>> /* 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, true);
>>> }
>>> 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..b5c5bee 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
>>> *
>>> @@ -335,6 +333,42 @@ static void drm_sched_job_timedout(struct
>>> work_struct *work)
>>> spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> }
>> Kernel doc here would be nice to have.
>>
>>> +void drm_sched_increase_karma(struct drm_sched_job *bad)
>>> +{
>>> + int i;
>>> + struct drm_sched_entity *tmp;
>>> + struct drm_sched_entity *entity;
>>> + struct drm_gpu_scheduler *sched = bad->sched;
>>> +
>>> + /* don't increase @bad's karma if it's from KERNEL RQ,
>>> + * because sometimes GPU hang would cause kernel jobs (like VM
>>> updating jobs)
>>> + * corrupt but keep in mind that kernel jobs always considered
>>> good.
>>> + */
>>> + if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
>>> + atomic_inc(&bad->karma);
>>> + for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_KERNEL;
>>> + i++) {
>>> + struct drm_sched_rq *rq = &sched->sched_rq[i];
>>> +
>>> + spin_lock(&rq->lock);
>>> + list_for_each_entry_safe(entity, tmp, &rq->entities,
>>> list) {
>>> + if (bad->s_fence->scheduled.context ==
>>> + entity->fence_context) {
>>> + if (atomic_read(&bad->karma) >
>>> + bad->sched->hang_limit)
>>> + if (entity->guilty)
>>> + atomic_set(entity->guilty, 1);
>>> + break;
>>> + }
>>> + }
>>> + spin_unlock(&rq->lock);
>>> + if (&entity->list != &rq->entities)
>>> + break;
>>> + }
>>> + }
>>> +}
>>> +EXPORT_SYMBOL(drm_sched_increase_karma);
>>> +
>>> /**
>>> * drm_sched_hw_job_reset - stop the scheduler if it contains the
>>> bad job
>>> *
>>> @@ -342,13 +376,22 @@ 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)
>>> {
>>> - struct drm_sched_job *s_job;
>>> - struct drm_sched_entity *entity, *tmp;
>>> + struct drm_sched_job *s_job, *last_job;
>>> unsigned long flags;
>>> - int i;
>>> + struct dma_fence *wait_fence = NULL;
>>> + int r;
>>> +
>>> + kthread_park(sched->thread);
>>> + /*
>>> + * Verify all the signaled jobs in mirror list are removed from
>>> the ring
>>> + * by waiting for their respective scheduler fences to signal.
>>> + * Continually repeat traversing the ring mirror list until no
>>> more signaled
>>> + * fences are found
>>> + */
>>> +retry_wait:
>>> 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 &&
>>> @@ -357,35 +400,45 @@ void drm_sched_hw_job_reset(struct
>>> drm_gpu_scheduler *sched, struct drm_sched_jo
>>> dma_fence_put(s_job->s_fence->parent);
>>> s_job->s_fence->parent = NULL;
>>> atomic_dec(&sched->hw_rq_count);
>>> + } else {
>>> + wait_fence = dma_fence_get(&s_job->s_fence->finished);
>>> + last_job = s_job;
>>> + break;
>>> }
>>> }
>>> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> - 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,
>>> - * becuase sometimes GPU hang would cause kernel jobs (like
>>> VM updating jobs)
>>> - * corrupt but keep in mind that kernel jobs always
>>> considered good.
>>> - */
>>> - for (i = DRM_SCHED_PRIORITY_MIN; i <
>>> DRM_SCHED_PRIORITY_KERNEL; i++ ) {
>>> - struct drm_sched_rq *rq = &sched->sched_rq[i];
>>> + /* No signaled jobs in the ring, its safe to proceed to ASIC
>>> reset */
>>> + if (!wait_fence) {
>>> + spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> + goto done;
>>> + }
>>> - spin_lock(&rq->lock);
>>> - list_for_each_entry_safe(entity, tmp, &rq->entities,
>>> list) {
>>> - if (bad->s_fence->scheduled.context ==
>>> entity->fence_context) {
>>> - if (atomic_read(&bad->karma) >
>>> bad->sched->hang_limit)
>>> - if (entity->guilty)
>>> - atomic_set(entity->guilty, 1);
>>> - break;
>>> - }
>>> - }
>>> - spin_unlock(&rq->lock);
>>> - if (&entity->list != &rq->entities)
>>> - break;
>>> + /* Restore removed cb since removing again already removed cb is
>>> undefined */
>>> + list_for_each_entry_reverse(s_job, &sched->ring_mirror_list,
>>> node) {
>>> + if(s_job == last_job)
>>> + break;
>> Need to double check after the holidays, but you should be able to use
>> list_for_each_entry_continue here.
> I think it should work - kind of traversing back on all the jobs we just
> removed their callbacks.
Wrapping your head around stuff again after the holidays sometimes shows
new problems we have completely missed :)
Adding the callbacks again won't work because we have freed up our
reference to the hardware fence above:
> dma_fence_put(s_job->s_fence->parent);
> s_job->s_fence->parent = NULL;
We need to drop this or we would never be able to re-add the fences.
But I'm still not sure if we shouldn't rely on the correct order of
signaling and simplify this instead.
Regards,
Christian.
>
> Andrey
>
>>> +
>>> + if (s_job->s_fence->parent) {
>>> + r = dma_fence_add_callback(s_job->s_fence->parent,
>>> + &s_job->s_fence->cb,
>>> + drm_sched_process_job);
>>> + if (r)
>>> + DRM_ERROR("fence restore callback failed (%d)\n",
>>> + r);
>> When you fail to add the callback this means that you need to call
>> call drm_sched_process_job manually here.
>>
>>> }
>>> }
>>> + spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> +
>>> + dma_fence_wait(wait_fence, false);
>>> + dma_fence_put(wait_fence);
>>> + wait_fence = NULL;
>>> +
>>> + goto retry_wait;
>>> +
>>> +done:
>>> + return;
>> Drop the done: label and return directly above.
>>
>> Apart from all those nit picks that starts to look like it should work,
>> Christian.
>>
>>> }
>>> -EXPORT_SYMBOL(drm_sched_hw_job_reset);
>>> +EXPORT_SYMBOL(drm_sched_stop);
>>> /**
>>> * drm_sched_job_recovery - recover jobs after a reset
>>> @@ -393,33 +446,21 @@ 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
>>> full_recovery)
>>> {
>>> struct drm_sched_job *s_job, *tmp;
>>> - bool found_guilty = false;
>>> unsigned long flags;
>>> int r;
>>> + if (!full_recovery)
>>> + 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;
>>> - uint64_t guilty_context;
>>> -
>>> - if (!found_guilty && atomic_read(&s_job->karma) >
>>> sched->hang_limit) {
>>> - found_guilty = true;
>>> - guilty_context = s_job->s_fence->scheduled.context;
>>> - }
>>> -
>>> - 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);
>>> + struct dma_fence *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 +468,47 @@ 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_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;
>>> + uint64_t guilty_context;
>>> + bool found_guilty = false;
>>> +
>>> + /*TODO DO we need spinlock here ? */
>>> + list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list,
>>> node) {
>>> + struct drm_sched_fence *s_fence = s_job->s_fence;
>>> +
>>> + if (!found_guilty && atomic_read(&s_job->karma) >
>>> sched->hang_limit) {
>>> + found_guilty = true;
>>> + guilty_context = s_job->s_fence->scheduled.context;
>>> + }
>>> +
>>> + if (found_guilty && s_job->s_fence->scheduled.context ==
>>> guilty_context)
>>> + dma_fence_set_error(&s_fence->finished, -ECANCELED);
>>> +
>>> + s_job->s_fence->parent = sched->ops->run_job(s_job);
>>> + atomic_inc(&sched->hw_rq_count);
>>> + }
>>> }
>>> -EXPORT_SYMBOL(drm_sched_job_recovery);
>>> +EXPORT_SYMBOL(drm_sched_resubmit_jobs);
>>> /**
>>> * drm_sched_job_init - init a scheduler job
>>> @@ -634,26 +704,14 @@ 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..f76d9ed 100644
>>> --- a/drivers/gpu/drm/v3d/v3d_sched.c
>>> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
>>> @@ -178,18 +178,22 @@ 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 ?
>>> + drm_sched_stop(sched, (sched_job->sched == sched ?
>>> sched_job : NULL));
>>> +
>>> + if(sched_job)
>>> + drm_sched_increase_karma(sched_job);
>>> }
>>> /* 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, true);
>>> }
>>> mutex_unlock(&v3d->reset_lock);
>>> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
>>> index 47e1979..5ab2d97 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);
>>> +void drm_sched_start(struct drm_gpu_scheduler *sched, bool
>>> full_recovery);
>>> +void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
>>> +void drm_sched_increase_karma(struct drm_sched_job *bad);
>>> 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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