On Tue, Jun 28, 2016 at 03:04:18PM +0800, Chunming Zhou wrote:
> ring_mirror_list is only used kthread context, no need to spinlock.
> otherwise deadlock happens when kthread_park.
>
Yes, in process context, we prefer to use mutex, because it avoids to
grab the CPU all the time.
Reviewed-by: Huang Rui <ray.huang at amd.com>
> Change-Id: I906022297015faf14a0ddb5f62a728af3e5f9448
> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
> ---
> drivers/gpu/drm/amd/scheduler/gpu_scheduler.c | 12 +++++-------
> drivers/gpu/drm/amd/scheduler/gpu_scheduler.h | 2 +-
> 2 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
> index b53cf58..3373d97 100644
> --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
> +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
> @@ -331,10 +331,9 @@ static void amd_sched_job_finish(struct work_struct *work)
> struct amd_sched_job *s_job = container_of(work, struct amd_sched_job,
> finish_work);
> struct amd_gpu_scheduler *sched = s_job->sched;
> - unsigned long flags;
>
> /* remove job from ring_mirror_list */
> - spin_lock_irqsave(&sched->job_list_lock, flags);
> + mutex_lock(&sched->job_list_lock);
> list_del_init(&s_job->node);
> if (sched->timeout != MAX_SCHEDULE_TIMEOUT) {
> struct amd_sched_job *next;
> @@ -348,7 +347,7 @@ static void amd_sched_job_finish(struct work_struct *work)
> if (next)
> schedule_delayed_work(&next->work_tdr, sched->timeout);
> }
> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
> + mutex_unlock(&sched->job_list_lock);
> sched->ops->free_job(s_job);
> }
>
> @@ -362,15 +361,14 @@ static void amd_sched_job_finish_cb(struct fence *f, struct fence_cb *cb)
> static void amd_sched_job_begin(struct amd_sched_job *s_job)
> {
> struct amd_gpu_scheduler *sched = s_job->sched;
> - unsigned long flags;
>
> - spin_lock_irqsave(&sched->job_list_lock, flags);
> + mutex_lock(&sched->job_list_lock);
> list_add_tail(&s_job->node, &sched->ring_mirror_list);
> if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
> list_first_entry_or_null(&sched->ring_mirror_list,
> struct amd_sched_job, node) == s_job)
> schedule_delayed_work(&s_job->work_tdr, sched->timeout);
> - spin_unlock_irqrestore(&sched->job_list_lock, flags);
> + mutex_unlock(&sched->job_list_lock);
> }
>
> static void amd_sched_job_timedout(struct work_struct *work)
> @@ -564,7 +562,7 @@ int amd_sched_init(struct amd_gpu_scheduler *sched,
> init_waitqueue_head(&sched->wake_up_worker);
> init_waitqueue_head(&sched->job_scheduled);
> INIT_LIST_HEAD(&sched->ring_mirror_list);
> - spin_lock_init(&sched->job_list_lock);
> + mutex_init(&sched->job_list_lock);
> atomic_set(&sched->hw_rq_count, 0);
> if (atomic_inc_return(&sched_fence_slab_ref) == 1) {
> sched_fence_slab = kmem_cache_create(
> diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
> index 221a515..5675906 100644
> --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
> +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
> @@ -132,7 +132,7 @@ struct amd_gpu_scheduler {
> atomic_t hw_rq_count;
> struct task_struct *thread;
> struct list_head ring_mirror_list;
> - spinlock_t job_list_lock;
> + struct mutex job_list_lock;
> };
>
> int amd_sched_init(struct amd_gpu_scheduler *sched,
> --
> 1.9.1
>
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