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

Grodzovsky, Andrey
2018-12-06T21:27:58Z

On 12/06/2018 01:33 PM, Christian König wrote:
> 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.

Please note I've already resent V2 after finding refactoring error.

Andrey

>
>> ---
>>   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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