diff options
Diffstat (limited to 'include/drm/gpu_scheduler.h')
| -rw-r--r-- | include/drm/gpu_scheduler.h | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 10225a0a35d0..88ae7f331bb1 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -239,6 +239,38 @@ struct drm_sched_backend_ops { * @timedout_job: Called when a job has taken too long to execute, * to trigger GPU recovery. * + * This method is called in a workqueue context. + * + * Drivers typically issue a reset to recover from GPU hangs, and this + * procedure usually follows the following workflow: + * + * 1. Stop the scheduler using drm_sched_stop(). This will park the + * scheduler thread and cancel the timeout work, guaranteeing that + * nothing is queued while we reset the hardware queue + * 2. Try to gracefully stop non-faulty jobs (optional) + * 3. Issue a GPU reset (driver-specific) + * 4. Re-submit jobs using drm_sched_resubmit_jobs() + * 5. Restart the scheduler using drm_sched_start(). At that point, new + * jobs can be queued, and the scheduler thread is unblocked + * + * Note that some GPUs have distinct hardware queues but need to reset + * the GPU globally, which requires extra synchronization between the + * timeout handler of the different &drm_gpu_scheduler. One way to + * achieve this synchronization is to create an ordered workqueue + * (using alloc_ordered_workqueue()) at the driver level, and pass this + * queue to drm_sched_init(), to guarantee that timeout handlers are + * executed sequentially. The above workflow needs to be slightly + * adjusted in that case: + * + * 1. Stop all schedulers impacted by the reset using drm_sched_stop() + * 2. Try to gracefully stop non-faulty jobs on all queues impacted by + * the reset (optional) + * 3. Issue a GPU reset on all faulty queues (driver-specific) + * 4. Re-submit jobs on all schedulers impacted by the reset using + * drm_sched_resubmit_jobs() + * 5. Restart all schedulers that were stopped in step #1 using + * drm_sched_start() + * * Return DRM_GPU_SCHED_STAT_NOMINAL, when all is normal, * and the underlying driver has started or completed recovery. * @@ -269,13 +301,14 @@ struct drm_sched_backend_ops { * finished. * @hw_rq_count: the number of jobs currently in the hardware queue. * @job_id_count: used to assign unique id to the each job. + * @timeout_wq: workqueue used to queue @work_tdr * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the * timeout interval is over. * @thread: the kthread on which the scheduler which run. * @pending_list: the list of jobs which are currently in the job queue. * @job_list_lock: lock to protect the pending_list. * @hang_limit: once the hangs by a job crosses this limit then it is marked - * guilty and it will be considered for scheduling further. + * guilty and it will no longer be considered for scheduling. * @score: score to help loadbalancer pick a idle sched * @_score: score used when the driver doesn't provide one * @ready: marks if the underlying HW is ready to work @@ -293,6 +326,7 @@ struct drm_gpu_scheduler { wait_queue_head_t job_scheduled; atomic_t hw_rq_count; atomic64_t job_id_count; + struct workqueue_struct *timeout_wq; struct delayed_work work_tdr; struct task_struct *thread; struct list_head pending_list; @@ -306,7 +340,8 @@ struct drm_gpu_scheduler { int drm_sched_init(struct drm_gpu_scheduler *sched, const struct drm_sched_backend_ops *ops, - uint32_t hw_submission, unsigned hang_limit, long timeout, + uint32_t hw_submission, unsigned hang_limit, + long timeout, struct workqueue_struct *timeout_wq, atomic_t *score, const char *name); void drm_sched_fini(struct drm_gpu_scheduler *sched); |