Hi Andrey,

static void drm_sched_process_job(struct dma_fence *f, struct 
dma_fence_cb *cb)
{
...
         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);
[David] How about just remove above to worker from irq process? Any 
problem? Maybe I missed previous your discussion, but I think removing 
lock for list is a risk for future maintenance although you make sure 
thread safe currently.

-David

...

         schedule_work(&s_job->finish_work);
}

在 2019/4/18 23:00, Andrey Grodzovsky 写道:
> From: Christian König <christian.koe...@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.
> v5:
> Move sched->hw_rq_count to drm_sched_start to account for counter
> decrement in drm_sched_stop even when we don't call resubmit jobs
> if guily job did signal.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109692
>
> Signed-off-by: Christian König <christian.koe...@amd.com>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzov...@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     | 159 
> +++++++++++++++++------------
>   drivers/gpu/drm/v3d/v3d_sched.c            |   2 +-
>   include/drm/gpu_scheduler.h                |   6 +-
>   8 files changed, 102 insertions(+), 84 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..7816de7 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);
> @@ -418,21 +416,22 @@ 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)
> -             goto unpark;
> -
>       /*
>        * 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) {
>               struct dma_fence *fence = s_job->s_fence->parent;
>   
> +             atomic_inc(&sched->hw_rq_count);
> +
> +             if (!full_recovery)
> +                     continue;
> +
>               if (fence) {
>                       r = dma_fence_add_callback(fence, &s_job->cb,
>                                                  drm_sched_process_job);
> @@ -445,9 +444,12 @@ void drm_sched_start(struct drm_gpu_scheduler *sched, 
> bool full_recovery)
>                       drm_sched_process_job(NULL, &s_job->cb);
>       }
>   
> -     drm_sched_start_timeout(sched);
> +     if (full_recovery) {
> +             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);
> @@ -464,7 +466,6 @@ 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;
>   
> @@ -477,7 +478,6 @@ void drm_sched_resubmit_jobs(struct drm_gpu_scheduler 
> *sched)
>                       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_resubmit_jobs);
> @@ -514,7 +514,6 @@ 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 +596,53 @@ 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 +684,10 @@ 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);
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to