[PATCH v4 3/5] drm/scheduler: rework job destruction
Grodzovsky, Andrey
Andrey.Grodzovsky at amd.com
Wed Apr 17 17:53:45 UTC 2019
On 4/17/19 1:17 PM, Christian König wrote:
> I can't review this patch, since I'm one of the authors of it, but in
> general your changes look good to me now.
>
> For patch #5 I think it might be cleaner if we move incrementing of
> the hw_rq_count while starting the scheduler again.
But the increment of hw_rq_count is conditional on if the guilty job
was signaled, moving it into drm_sched_start will also force me to pass
'job_signaled' flag into drm_sched_start which is against your original
comment that we don't want to pass this logic around helper functions
and keep it all in one place which is amdgpu_device_gpu_recover.
Andrey
>
> Regards,
> Christian.
>
> Am 17.04.19 um 16:36 schrieb Grodzovsky, Andrey:
>> Ping on this patch and patch 5. The rest already RBed.
>>
>> Andrey
>>
>> On 4/16/19 2:23 PM, Andrey Grodzovsky wrote:
>>> From: Christian König <christian.koenig at amd.com>
>>>
>>> We now destroy finished jobs from the worker thread to make sure that
>>> we never destroy a job currently in timeout processing.
>>> By this we avoid holding lock around ring mirror list in drm_sched_stop
>>> which should solve a deadlock reported by a user.
>>>
>>> v2: Remove unused variable.
>>> v4: Move guilty job free into sched code.
>>>
>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109692
>>>
>>> Signed-off-by: Christian König <christian.koenig at amd.com>
>>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>>> ---
>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 9 +-
>>> drivers/gpu/drm/etnaviv/etnaviv_dump.c | 4 -
>>> drivers/gpu/drm/etnaviv/etnaviv_sched.c | 2 +-
>>> drivers/gpu/drm/lima/lima_sched.c | 2 +-
>>> drivers/gpu/drm/panfrost/panfrost_job.c | 2 +-
>>> drivers/gpu/drm/scheduler/sched_main.c | 145
>>> +++++++++++++++++------------
>>> drivers/gpu/drm/v3d/v3d_sched.c | 2 +-
>>> include/drm/gpu_scheduler.h | 6 +-
>>> 8 files changed, 94 insertions(+), 78 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> index 7cee269..a0e165c 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -3334,7 +3334,7 @@ static int amdgpu_device_pre_asic_reset(struct
>>> amdgpu_device *adev,
>>> if (!ring || !ring->sched.thread)
>>> continue;
>>> - drm_sched_stop(&ring->sched);
>>> + drm_sched_stop(&ring->sched, &job->base);
>>> /* after all hw jobs are reset, hw fence is
>>> meaningless, so force_completion */
>>> amdgpu_fence_driver_force_completion(ring);
>>> @@ -3343,8 +3343,6 @@ static int amdgpu_device_pre_asic_reset(struct
>>> amdgpu_device *adev,
>>> if(job)
>>> drm_sched_increase_karma(&job->base);
>>> -
>>> -
>>> if (!amdgpu_sriov_vf(adev)) {
>>> if (!need_full_reset)
>>> @@ -3482,8 +3480,7 @@ static int amdgpu_do_asic_reset(struct
>>> amdgpu_hive_info *hive,
>>> return r;
>>> }
>>> -static void amdgpu_device_post_asic_reset(struct amdgpu_device
>>> *adev,
>>> - struct amdgpu_job *job)
>>> +static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev)
>>> {
>>> int i;
>>> @@ -3623,7 +3620,7 @@ int amdgpu_device_gpu_recover(struct
>>> amdgpu_device *adev,
>>> /* Post ASIC reset for all devs .*/
>>> list_for_each_entry(tmp_adev, device_list_handle,
>>> gmc.xgmi.head) {
>>> - amdgpu_device_post_asic_reset(tmp_adev, tmp_adev == adev ?
>>> job : NULL);
>>> + amdgpu_device_post_asic_reset(tmp_adev);
>>> if (r) {
>>> /* bad news, how to tell it to userspace ? */
>>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_dump.c
>>> b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
>>> index 33854c9..5778d9c 100644
>>> --- a/drivers/gpu/drm/etnaviv/etnaviv_dump.c
>>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_dump.c
>>> @@ -135,13 +135,11 @@ void etnaviv_core_dump(struct etnaviv_gpu *gpu)
>>> mmu_size + gpu->buffer.size;
>>> /* Add in the active command buffers */
>>> - spin_lock_irqsave(&gpu->sched.job_list_lock, flags);
>>> list_for_each_entry(s_job, &gpu->sched.ring_mirror_list, node) {
>>> submit = to_etnaviv_submit(s_job);
>>> file_size += submit->cmdbuf.size;
>>> n_obj++;
>>> }
>>> - spin_unlock_irqrestore(&gpu->sched.job_list_lock, flags);
>>> /* Add in the active buffer objects */
>>> list_for_each_entry(vram, &gpu->mmu->mappings, mmu_node) {
>>> @@ -183,14 +181,12 @@ void etnaviv_core_dump(struct etnaviv_gpu *gpu)
>>> gpu->buffer.size,
>>> etnaviv_cmdbuf_get_va(&gpu->buffer));
>>> - spin_lock_irqsave(&gpu->sched.job_list_lock, flags);
>>> list_for_each_entry(s_job, &gpu->sched.ring_mirror_list, node) {
>>> submit = to_etnaviv_submit(s_job);
>>> etnaviv_core_dump_mem(&iter, ETDUMP_BUF_CMD,
>>> submit->cmdbuf.vaddr, submit->cmdbuf.size,
>>> etnaviv_cmdbuf_get_va(&submit->cmdbuf));
>>> }
>>> - spin_unlock_irqrestore(&gpu->sched.job_list_lock, flags);
>>> /* Reserve space for the bomap */
>>> if (n_bomap_pages) {
>>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> index 6d24fea..a813c82 100644
>>> --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c
>>> @@ -109,7 +109,7 @@ static void etnaviv_sched_timedout_job(struct
>>> drm_sched_job *sched_job)
>>> }
>>> /* block scheduler */
>>> - drm_sched_stop(&gpu->sched);
>>> + drm_sched_stop(&gpu->sched, sched_job);
>>> if(sched_job)
>>> drm_sched_increase_karma(sched_job);
>>> diff --git a/drivers/gpu/drm/lima/lima_sched.c
>>> b/drivers/gpu/drm/lima/lima_sched.c
>>> index 97bd9c1..df98931 100644
>>> --- a/drivers/gpu/drm/lima/lima_sched.c
>>> +++ b/drivers/gpu/drm/lima/lima_sched.c
>>> @@ -300,7 +300,7 @@ static struct dma_fence
>>> *lima_sched_run_job(struct drm_sched_job *job)
>>> static void lima_sched_handle_error_task(struct lima_sched_pipe
>>> *pipe,
>>> struct lima_sched_task *task)
>>> {
>>> - drm_sched_stop(&pipe->base);
>>> + drm_sched_stop(&pipe->base, &task->base);
>>> if (task)
>>> drm_sched_increase_karma(&task->base);
>>> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c
>>> b/drivers/gpu/drm/panfrost/panfrost_job.c
>>> index 0a7ed04..c6336b7 100644
>>> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
>>> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
>>> @@ -385,7 +385,7 @@ static void panfrost_job_timedout(struct
>>> drm_sched_job *sched_job)
>>> sched_job);
>>> for (i = 0; i < NUM_JOB_SLOTS; i++)
>>> - drm_sched_stop(&pfdev->js->queue[i].sched);
>>> + drm_sched_stop(&pfdev->js->queue[i].sched, sched_job);
>>> if (sched_job)
>>> drm_sched_increase_karma(sched_job);
>>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
>>> b/drivers/gpu/drm/scheduler/sched_main.c
>>> index 19fc601..21e8734 100644
>>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>>> @@ -265,32 +265,6 @@ void drm_sched_resume_timeout(struct
>>> drm_gpu_scheduler *sched,
>>> }
>>> EXPORT_SYMBOL(drm_sched_resume_timeout);
>>> -/* job_finish is called after hw fence signaled
>>> - */
>>> -static void drm_sched_job_finish(struct work_struct *work)
>>> -{
>>> - struct drm_sched_job *s_job = container_of(work, struct
>>> drm_sched_job,
>>> - finish_work);
>>> - struct drm_gpu_scheduler *sched = s_job->sched;
>>> - unsigned long flags;
>>> -
>>> - /*
>>> - * Canceling the timeout without removing our job from the ring
>>> mirror
>>> - * list is safe, as we will only end up in this worker if our jobs
>>> - * finished fence has been signaled. So even if some another
>>> worker
>>> - * manages to find this job as the next job in the list, the fence
>>> - * signaled check below will prevent the timeout to be restarted.
>>> - */
>>> - cancel_delayed_work_sync(&sched->work_tdr);
>>> -
>>> - spin_lock_irqsave(&sched->job_list_lock, flags);
>>> - /* queue TDR for next job */
>>> - drm_sched_start_timeout(sched);
>>> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> -
>>> - sched->ops->free_job(s_job);
>>> -}
>>> -
>>> static void drm_sched_job_begin(struct drm_sched_job *s_job)
>>> {
>>> struct drm_gpu_scheduler *sched = s_job->sched;
>>> @@ -315,6 +289,13 @@ static void drm_sched_job_timedout(struct
>>> work_struct *work)
>>> if (job)
>>> job->sched->ops->timedout_job(job);
>>> + /*
>>> + * Guilty job did complete and hence needs to be manually removed
>>> + * See drm_sched_stop doc.
>>> + */
>>> + if (list_empty(&job->node))
>>> + job->sched->ops->free_job(job);
>>> +
>>> spin_lock_irqsave(&sched->job_list_lock, flags);
>>> drm_sched_start_timeout(sched);
>>> spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> @@ -371,23 +352,26 @@ EXPORT_SYMBOL(drm_sched_increase_karma);
>>> * @sched: scheduler instance
>>> * @bad: bad scheduler job
>>> *
>>> + * Stop the scheduler and also removes and frees all completed jobs.
>>> + * Note: bad job will not be freed as it might be used later and so
>>> it's
>>> + * callers responsibility to release it manually if it's not part
>>> of the
>>> + * mirror list any more.
>>> + *
>>> */
>>> -void drm_sched_stop(struct drm_gpu_scheduler *sched)
>>> +void drm_sched_stop(struct drm_gpu_scheduler *sched, struct
>>> drm_sched_job *bad)
>>> {
>>> - struct drm_sched_job *s_job;
>>> + struct drm_sched_job *s_job, *tmp;
>>> unsigned long flags;
>>> - struct dma_fence *last_fence = NULL;
>>> kthread_park(sched->thread);
>>> /*
>>> - * Verify all the signaled jobs in mirror list are removed from
>>> the ring
>>> - * by waiting for the latest job to enter the list. This should
>>> insure that
>>> - * also all the previous jobs that were in flight also already
>>> singaled
>>> - * and removed from the list.
>>> + * Iterate the job list from later to earlier one and either
>>> deactive
>>> + * their HW callbacks or remove them from mirror list if they
>>> already
>>> + * signaled.
>>> + * This iteration is thread safe as sched thread is stopped.
>>> */
>>> - spin_lock_irqsave(&sched->job_list_lock, flags);
>>> - list_for_each_entry_reverse(s_job, &sched->ring_mirror_list,
>>> node) {
>>> + list_for_each_entry_safe_reverse(s_job, tmp,
>>> &sched->ring_mirror_list, node) {
>>> if (s_job->s_fence->parent &&
>>> dma_fence_remove_callback(s_job->s_fence->parent,
>>> &s_job->cb)) {
>>> @@ -395,16 +379,30 @@ void drm_sched_stop(struct drm_gpu_scheduler
>>> *sched)
>>> s_job->s_fence->parent = NULL;
>>> atomic_dec(&sched->hw_rq_count);
>>> } else {
>>> - last_fence = dma_fence_get(&s_job->s_fence->finished);
>>> - break;
>>> + /*
>>> + * remove job from ring_mirror_list.
>>> + * Locking here is for concurrent resume timeout
>>> + */
>>> + spin_lock_irqsave(&sched->job_list_lock, flags);
>>> + list_del_init(&s_job->node);
>>> + spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> +
>>> + /*
>>> + * Wait for job's HW fence callback to finish using s_job
>>> + * before releasing it.
>>> + *
>>> + * Job is still alive so fence refcount at least 1
>>> + */
>>> + dma_fence_wait(&s_job->s_fence->finished, false);
>>> +
>>> + /*
>>> + * We must keep bad job alive for later use during
>>> + * recovery by some of the drivers
>>> + */
>>> + if (bad != s_job)
>>> + sched->ops->free_job(s_job);
>>> }
>>> }
>>> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> -
>>> - if (last_fence) {
>>> - dma_fence_wait(last_fence, false);
>>> - dma_fence_put(last_fence);
>>> - }
>>> }
>>> EXPORT_SYMBOL(drm_sched_stop);
>>> @@ -418,6 +416,7 @@ EXPORT_SYMBOL(drm_sched_stop);
>>> void drm_sched_start(struct drm_gpu_scheduler *sched, bool
>>> full_recovery)
>>> {
>>> struct drm_sched_job *s_job, *tmp;
>>> + unsigned long flags;
>>> int r;
>>> if (!full_recovery)
>>> @@ -425,9 +424,7 @@ void drm_sched_start(struct drm_gpu_scheduler
>>> *sched, bool full_recovery)
>>> /*
>>> * 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
>>> + * so no new jobs are being inserted or removed. Also concurrent
>>> * GPU recovers can't run in parallel.
>>> */
>>> list_for_each_entry_safe(s_job, tmp,
>>> &sched->ring_mirror_list, node) {
>>> @@ -445,7 +442,9 @@ void drm_sched_start(struct drm_gpu_scheduler
>>> *sched, bool full_recovery)
>>> drm_sched_process_job(NULL, &s_job->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);
>>> @@ -464,7 +463,6 @@ void drm_sched_resubmit_jobs(struct
>>> drm_gpu_scheduler *sched)
>>> 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;
>>> @@ -514,7 +512,6 @@ int drm_sched_job_init(struct drm_sched_job
>>> *job,
>>> return -ENOMEM;
>>> job->id = atomic64_inc_return(&sched->job_id_count);
>>> - INIT_WORK(&job->finish_work, drm_sched_job_finish);
>>> INIT_LIST_HEAD(&job->node);
>>> return 0;
>>> @@ -597,24 +594,53 @@ static void drm_sched_process_job(struct
>>> dma_fence *f, struct dma_fence_cb *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);
>>> 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);
>>> + trace_drm_sched_process_job(s_fence);
>>> drm_sched_fence_finished(s_fence);
>>> -
>>> - trace_drm_sched_process_job(s_fence);
>>> wake_up_interruptible(&sched->wake_up_worker);
>>> +}
>>> +
>>> +/**
>>> + * drm_sched_cleanup_jobs - destroy finished jobs
>>> + *
>>> + * @sched: scheduler instance
>>> + *
>>> + * Remove all finished jobs from the mirror list and destroy them.
>>> + */
>>> +static void drm_sched_cleanup_jobs(struct drm_gpu_scheduler *sched)
>>> +{
>>> + unsigned long flags;
>>> +
>>> + /* Don't destroy jobs while the timeout worker is running */
>>> + if (!cancel_delayed_work(&sched->work_tdr))
>>> + return;
>>> +
>>> +
>>> + while (!list_empty(&sched->ring_mirror_list)) {
>>> + struct drm_sched_job *job;
>>> +
>>> + job = list_first_entry(&sched->ring_mirror_list,
>>> + struct drm_sched_job, node);
>>> + if (!dma_fence_is_signaled(&job->s_fence->finished))
>>> + break;
>>> +
>>> + spin_lock_irqsave(&sched->job_list_lock, flags);
>>> + /* remove job from ring_mirror_list */
>>> + list_del_init(&job->node);
>>> + spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> +
>>> + sched->ops->free_job(job);
>>> + }
>>> +
>>> + /* queue timeout for next job */
>>> + spin_lock_irqsave(&sched->job_list_lock, flags);
>>> + drm_sched_start_timeout(sched);
>>> + spin_unlock_irqrestore(&sched->job_list_lock, flags);
>>> - schedule_work(&s_job->finish_work);
>>> }
>>> /**
>>> @@ -656,9 +682,10 @@ static int drm_sched_main(void *param)
>>> struct dma_fence *fence;
>>> wait_event_interruptible(sched->wake_up_worker,
>>> + (drm_sched_cleanup_jobs(sched),
>>> (!drm_sched_blocked(sched) &&
>>> (entity = drm_sched_select_entity(sched))) ||
>>> - kthread_should_stop());
>>> + kthread_should_stop()));
>>> if (!entity)
>>> continue;
>>> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c
>>> b/drivers/gpu/drm/v3d/v3d_sched.c
>>> index e740f3b..1a4abe7 100644
>>> --- a/drivers/gpu/drm/v3d/v3d_sched.c
>>> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
>>> @@ -232,7 +232,7 @@ v3d_gpu_reset_for_timeout(struct v3d_dev *v3d,
>>> struct drm_sched_job *sched_job)
>>> /* block scheduler */
>>> for (q = 0; q < V3D_MAX_QUEUES; q++)
>>> - drm_sched_stop(&v3d->queue[q].sched);
>>> + drm_sched_stop(&v3d->queue[q].sched, sched_job);
>>> if (sched_job)
>>> drm_sched_increase_karma(sched_job);
>>> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
>>> index 0daca4d..9ee0f27 100644
>>> --- a/include/drm/gpu_scheduler.h
>>> +++ b/include/drm/gpu_scheduler.h
>>> @@ -167,9 +167,6 @@ struct drm_sched_fence
>>> *to_drm_sched_fence(struct dma_fence *f);
>>> * @sched: the scheduler instance on which this job is scheduled.
>>> * @s_fence: contains the fences for the scheduling of job.
>>> * @finish_cb: the callback for the finished fence.
>>> - * @finish_work: schedules the function @drm_sched_job_finish once
>>> the job has
>>> - * 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.
>>> * @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
>>> @@ -188,7 +185,6 @@ struct drm_sched_job {
>>> struct drm_gpu_scheduler *sched;
>>> struct drm_sched_fence *s_fence;
>>> struct dma_fence_cb finish_cb;
>>> - struct work_struct finish_work;
>>> struct list_head node;
>>> uint64_t id;
>>> atomic_t karma;
>>> @@ -296,7 +292,7 @@ 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_stop(struct drm_gpu_scheduler *sched);
>>> +void drm_sched_stop(struct drm_gpu_scheduler *sched, struct
>>> drm_sched_job *bad);
>>> 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);
>
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