diff options
author | Christian König <christian.koenig@amd.com> | 2019-04-18 11:00:21 -0400 |
---|---|---|
committer | Alex Deucher <alexander.deucher@amd.com> | 2019-05-02 15:45:48 -0500 |
commit | 5918045c4ed492fb5813f980dcf89a90fefd0a4e (patch) | |
tree | a59c6f9bb006645b8fc46164d7fb53cb38b24294 /drivers/gpu/drm/scheduler | |
parent | b3198c38f02d54a5e964258a2180d502abe6eaf0 (diff) | |
download | linux-5918045c4ed492fb5813f980dcf89a90fefd0a4e.tar.bz2 |
drm/scheduler: rework job destruction
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.
v6: remove unused variable
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109692
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1555599624-12285-3-git-send-email-andrey.grodzovsky@amd.com
Diffstat (limited to 'drivers/gpu/drm/scheduler')
-rw-r--r-- | drivers/gpu/drm/scheduler/sched_main.c | 159 |
1 files changed, 94 insertions, 65 deletions
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 19fc601c9eeb..7816de7e8c82 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; |