Re: [PATCH V2 05/20] block: move sched debugfs register into elvevator_register_queue

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

在 2025/04/19 0:36, Ming Lei 写道:
> sched debugfs shares same lifetime with scheduler's kobject, and same
> lock(elevator lock), so move sched debugfs register/unregister into
> elevator_register_queue() and elevator_unregister_queue().
>
> Then we needn't blk_mq_debugfs_register() for us to register sched
> debugfs any more.
>
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
>   block/blk-mq-debugfs.c | 11 -----------
>   block/blk-mq-sched.c   | 11 ++---------
>   block/elevator.c       |  8 ++++++++
>   block/elevator.h       |  3 +++
>   4 files changed, 13 insertions(+), 20 deletions(-)
LGTM
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>

> diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
> index 31e249a18407..0fa0f8836b7d 100644
> --- a/block/blk-mq-debugfs.c
> +++ b/block/blk-mq-debugfs.c
> @@ -625,20 +625,9 @@ void blk_mq_debugfs_register(struct request_queue *q)
>   
>   	debugfs_create_files(q->debugfs_dir, q, blk_mq_debugfs_queue_attrs);
>   
> -	/*
> -	 * blk_mq_init_sched() attempted to do this already, but q->debugfs_dir
> -	 * didn't exist yet (because we don't know what to name the directory
> -	 * until the queue is registered to a gendisk).
> -	 */
> -	if (q->elevator && !q->sched_debugfs_dir)
> -		blk_mq_debugfs_register_sched(q);
> -
> -	/* Similarly, blk_mq_init_hctx() couldn't do this previously. */
>   	queue_for_each_hw_ctx(q, hctx, i) {
>   		if (!hctx->debugfs_dir)
>   			blk_mq_debugfs_register_hctx(q, hctx);
> -		if (q->elevator && !hctx->sched_debugfs_dir)
> -			blk_mq_debugfs_register_sched_hctx(q, hctx);
>   	}
>   
>   	if (q->rq_qos) {
> diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
> index 2abc5e0704e8..336a15ffecfa 100644
> --- a/block/blk-mq-sched.c
> +++ b/block/blk-mq-sched.c
> @@ -434,7 +434,7 @@ static int blk_mq_init_sched_shared_tags(struct request_queue *queue)
>   	return 0;
>   }
>   
> -static void blk_mq_sched_reg_debugfs(struct request_queue *q)
> +void blk_mq_sched_reg_debugfs(struct request_queue *q)
>   {
>   	struct blk_mq_hw_ctx *hctx;
>   	unsigned long i;
> @@ -446,7 +446,7 @@ static void blk_mq_sched_reg_debugfs(struct request_queue *q)
>   	mutex_unlock(&q->debugfs_mutex);
>   }
>   
> -static void blk_mq_sched_unreg_debugfs(struct request_queue *q)
> +void blk_mq_sched_unreg_debugfs(struct request_queue *q)
>   {
>   	struct blk_mq_hw_ctx *hctx;
>   	unsigned long i;
> @@ -503,10 +503,6 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
>   			}
>   		}
>   	}
> -
> -	/* sched is initialized, it is ready to export it via debugfs */
> -	blk_mq_sched_reg_debugfs(q);
> -
>   	return 0;
>   
>   err_free_map_and_rqs:
> @@ -544,9 +540,6 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
>   	unsigned long i;
>   	unsigned int flags = 0;
>   
> -	/* unexport via debugfs before exiting sched */
> -	blk_mq_sched_unreg_debugfs(q);
> -
>   	queue_for_each_hw_ctx(q, hctx, i) {
>   		if (e->type->ops.exit_hctx && hctx->sched_data) {
>   			e->type->ops.exit_hctx(hctx, i);
> diff --git a/block/elevator.c b/block/elevator.c
> index 5051a98dc08c..d25b9cc6c509 100644
> --- a/block/elevator.c
> +++ b/block/elevator.c
> @@ -472,6 +472,11 @@ int elv_register_queue(struct request_queue *q, bool uevent)
>   		if (uevent)
>   			kobject_uevent(&e->kobj, KOBJ_ADD);
>   
> +		/*
> +		 * Sched is initialized, it is ready to export it via
> +		 * debugfs
> +		 */
> +		blk_mq_sched_reg_debugfs(q);
>   		set_bit(ELEVATOR_FLAG_REGISTERED, &e->flags);
>   	}
>   	return error;
> @@ -486,6 +491,9 @@ void elv_unregister_queue(struct request_queue *q)
>   	if (e && test_and_clear_bit(ELEVATOR_FLAG_REGISTERED, &e->flags)) {
>   		kobject_uevent(&e->kobj, KOBJ_REMOVE);
>   		kobject_del(&e->kobj);
> +
> +		/* unexport via debugfs before exiting sched */
> +		blk_mq_sched_unreg_debugfs(q);
>   	}
>   }
>   
> diff --git a/block/elevator.h b/block/elevator.h
> index e27af5492cdb..9198676644a9 100644
> --- a/block/elevator.h
> +++ b/block/elevator.h
> @@ -181,4 +181,7 @@ extern struct request *elv_rb_find(struct rb_root *, sector_t);
>   #define rq_entry_fifo(ptr)	list_entry((ptr), struct request, queuelist)
>   #define rq_fifo_clear(rq)	list_del_init(&(rq)->queuelist)
>   
> +void blk_mq_sched_reg_debugfs(struct request_queue *q);
> +void blk_mq_sched_unreg_debugfs(struct request_queue *q);
> +
>   #endif /* _ELEVATOR_H */