Re: [PATCH v2] drm/sched/tests: Use one lock for fence context

From: Philipp Stanner
Date: Mon Jun 02 2025 - 07:28:53 EST


On Tue, 2025-05-27 at 12:10 +0200, Philipp Stanner wrote:
> There is no need for separate locks for single jobs and the entire
> scheduler. The dma_fence context can be protected by the scheduler
> lock,
> allowing for removing the jobs' locks. This simplifies things and
> reduces the likelyhood of deadlocks etc.
>
> Replace the jobs' locks with the mock scheduler lock.
>
> Signed-off-by: Philipp Stanner <phasta@xxxxxxxxxx>

Applied to drm-misc-next

P.

> ---
> Changes in v2:
>   - Make commit message more neutral by stating it's about
> simplifying
>     the code. (Tvrtko)
> ---
>  drivers/gpu/drm/scheduler/tests/mock_scheduler.c | 5 ++---
>  drivers/gpu/drm/scheduler/tests/sched_tests.h    | 1 -
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/tests/mock_scheduler.c
> b/drivers/gpu/drm/scheduler/tests/mock_scheduler.c
> index f999c8859cf7..17023276f4b0 100644
> --- a/drivers/gpu/drm/scheduler/tests/mock_scheduler.c
> +++ b/drivers/gpu/drm/scheduler/tests/mock_scheduler.c
> @@ -64,7 +64,7 @@ static void drm_mock_sched_job_complete(struct
> drm_mock_sched_job *job)
>  
>   job->flags |= DRM_MOCK_SCHED_JOB_DONE;
>   list_move_tail(&job->link, &sched->done_list);
> - dma_fence_signal(&job->hw_fence);
> + dma_fence_signal_locked(&job->hw_fence);
>   complete(&job->done);
>  }
>  
> @@ -123,7 +123,6 @@ drm_mock_sched_job_new(struct kunit *test,
>   job->test = test;
>  
>   init_completion(&job->done);
> - spin_lock_init(&job->lock);
>   INIT_LIST_HEAD(&job->link);
>   hrtimer_setup(&job->timer, drm_mock_sched_job_signal_timer,
>         CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
> @@ -169,7 +168,7 @@ static struct dma_fence
> *mock_sched_run_job(struct drm_sched_job *sched_job)
>  
>   dma_fence_init(&job->hw_fence,
>          &drm_mock_sched_hw_fence_ops,
> -        &job->lock,
> +        &sched->lock,
>          sched->hw_timeline.context,
>          atomic_inc_return(&sched-
> >hw_timeline.next_seqno));
>  
> diff --git a/drivers/gpu/drm/scheduler/tests/sched_tests.h
> b/drivers/gpu/drm/scheduler/tests/sched_tests.h
> index 27caf8285fb7..fbba38137f0c 100644
> --- a/drivers/gpu/drm/scheduler/tests/sched_tests.h
> +++ b/drivers/gpu/drm/scheduler/tests/sched_tests.h
> @@ -106,7 +106,6 @@ struct drm_mock_sched_job {
>   unsigned int duration_us;
>   ktime_t finish_at;
>  
> - spinlock_t lock;
>   struct dma_fence hw_fence;
>  
>   struct kunit *test;