Re: [PATCH v3 3/7] drm/xe: Add dedicated message lock

[Matthew Brost <matthew.brost@intel.com>]

On Mon, Nov 17, 2025 at 11:58:46AM -0800, Niranjana Vishwanathapura wrote:
> On Thu, Oct 16, 2025 at 01:48:22PM -0700, Matthew Brost wrote:
> > Stop abusing DRM scheduler job list lock for messages, add dedicated
> > message lock.
> > 
> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> 
> LGTM.
> Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
> 

Going to send this out on its own for CI and merge. Thanks for the review.

Matt

> > ---
> > drivers/gpu/drm/xe/xe_gpu_scheduler.c       | 5 +++--
> > drivers/gpu/drm/xe/xe_gpu_scheduler.h       | 4 ++--
> > drivers/gpu/drm/xe/xe_gpu_scheduler_types.h | 2 ++
> > 3 files changed, 7 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler.c b/drivers/gpu/drm/xe/xe_gpu_scheduler.c
> > index f91e06d03511..f4f23317191f 100644
> > --- a/drivers/gpu/drm/xe/xe_gpu_scheduler.c
> > +++ b/drivers/gpu/drm/xe/xe_gpu_scheduler.c
> > @@ -77,6 +77,7 @@ int xe_sched_init(struct xe_gpu_scheduler *sched,
> > 	};
> > 
> > 	sched->ops = xe_ops;
> > +	spin_lock_init(&sched->msg_lock);
> > 	INIT_LIST_HEAD(&sched->msgs);
> > 	INIT_WORK(&sched->work_process_msg, xe_sched_process_msg_work);
> > 
> > @@ -117,7 +118,7 @@ void xe_sched_add_msg(struct xe_gpu_scheduler *sched,
> > void xe_sched_add_msg_locked(struct xe_gpu_scheduler *sched,
> > 			     struct xe_sched_msg *msg)
> > {
> > -	lockdep_assert_held(&sched->base.job_list_lock);
> > +	lockdep_assert_held(&sched->msg_lock);
> > 
> > 	list_add_tail(&msg->link, &sched->msgs);
> > 	xe_sched_process_msg_queue(sched);
> > @@ -131,7 +132,7 @@ void xe_sched_add_msg_locked(struct xe_gpu_scheduler *sched,
> > void xe_sched_add_msg_head(struct xe_gpu_scheduler *sched,
> > 			   struct xe_sched_msg *msg)
> > {
> > -	lockdep_assert_held(&sched->base.job_list_lock);
> > +	lockdep_assert_held(&sched->msg_lock);
> > 
> > 	list_add(&msg->link, &sched->msgs);
> > 	xe_sched_process_msg_queue(sched);
> > diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler.h b/drivers/gpu/drm/xe/xe_gpu_scheduler.h
> > index 9955397aaaa9..b971b6b69419 100644
> > --- a/drivers/gpu/drm/xe/xe_gpu_scheduler.h
> > +++ b/drivers/gpu/drm/xe/xe_gpu_scheduler.h
> > @@ -33,12 +33,12 @@ void xe_sched_add_msg_head(struct xe_gpu_scheduler *sched,
> > 
> > static inline void xe_sched_msg_lock(struct xe_gpu_scheduler *sched)
> > {
> > -	spin_lock(&sched->base.job_list_lock);
> > +	spin_lock(&sched->msg_lock);
> > }
> > 
> > static inline void xe_sched_msg_unlock(struct xe_gpu_scheduler *sched)
> > {
> > -	spin_unlock(&sched->base.job_list_lock);
> > +	spin_unlock(&sched->msg_lock);
> > }
> > 
> > static inline void xe_sched_stop(struct xe_gpu_scheduler *sched)
> > diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h b/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h
> > index 6731b13da8bb..63d9bf92583c 100644
> > --- a/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h
> > +++ b/drivers/gpu/drm/xe/xe_gpu_scheduler_types.h
> > @@ -47,6 +47,8 @@ struct xe_gpu_scheduler {
> > 	const struct xe_sched_backend_ops	*ops;
> > 	/** @msgs: list of messages to be processed in @work_process_msg */
> > 	struct list_head			msgs;
> > +	/** @msg_lock: Message lock */
> > +	spinlock_t				msg_lock;
> > 	/** @work_process_msg: processes messages */
> > 	struct work_struct		work_process_msg;
> > };
> > -- 
> > 2.34.1
> >