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.
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 | 17 ++-- drivers/gpu/drm/etnaviv/etnaviv_dump.c | 4 - drivers/gpu/drm/etnaviv/etnaviv_sched.c | 9 +- drivers/gpu/drm/scheduler/sched_main.c | 140 +++++++++++++++++------------ drivers/gpu/drm/v3d/v3d_sched.c | 9 +- include/drm/gpu_scheduler.h | 6 +- 6 files changed, 110 insertions(+), 75 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index fcb3d95..aabd043 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -3339,15 +3339,23 @@ 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); } - if(job) + if(job) { drm_sched_increase_karma(&job->base); + /* + * Guilty job did complete and hence needs to be manually removed + * See drm_sched_stop doc. + */ + if (list_empty(&job->base.node)) + job->base.sched->ops->free_job(&job->base); + } + if (!amdgpu_sriov_vf(adev)) { @@ -3487,8 +3495,7 @@ 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; @@ -3628,7 +3635,7 @@ 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 3fbb485..8434715 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 67ae266..8795c19 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c @@ -109,11 +109,18 @@ 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); + /* + * Guilty job did complete and hence needs to be manually removed + * See drm_sched_stop doc. + */ + if (list_empty(&sched_job->node)) + sched_job->sched->ops->free_job(sched_job); + /* get the GPU back into the init state */ etnaviv_core_dump(gpu); etnaviv_gpu_recover_hang(gpu); diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 19fc601..c215cde 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -191,6 +191,8 @@ EXPORT_SYMBOL(drm_sched_dependency_optimized); */ static void drm_sched_start_timeout(struct drm_gpu_scheduler *sched) { + unsigned long flags; + if (sched->timeout != MAX_SCHEDULE_TIMEOUT && !list_empty(&sched->ring_mirror_list)) schedule_delayed_work(&sched->work_tdr, sched->timeout); @@ -265,32 +267,6 @@ 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; @@ -371,23 +347,26 @@ 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 +374,30 @@ 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 +411,7 @@ 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 +419,7 @@ 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 +437,9 @@ 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 +458,6 @@ 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 +507,6 @@ 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 +589,53 @@ 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 +677,10 @@ 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 ce7c737b..8efb091 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -232,11 +232,18 @@ 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); + /* + * Guilty job did complete and hence needs to be manually removed + * See drm_sched_stop doc. + */ + if (list_empty(&sched_job->node)) + sched_job->sched->ops->free_job(sched_job); + /* get the GPU back into the init state */ v3d_reset(v3d); 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); -- 2.7.4 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
