[PATCH v4 3/5] drm/scheduler: rework job destruction
Christian König
ckoenig.leichtzumerken at gmail.com
Wed Apr 17 17:59:02 UTC 2019
Am 17.04.19 um 19:53 schrieb Grodzovsky, Andrey:
> 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.
Well I hope that incrementing hw_rq_count is conditional for signaled
jobs anyway, or otherwise we would seriously mess up the counter.
E.g. in drm_sched_stop() we also only decrement it when we where able to
remove the callback.
Christian.
>
> 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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