diff mbox series

[V2,02/20] block: move ELEVATOR_FLAG_DISABLE_WBT as request queue flag

Message ID 20250418163708.442085-3-ming.lei@redhat.com (mailing list archive)
State New
Headers show
Series block: unify elevator changing and fix lockdep warning | expand

Commit Message

Ming Lei April 18, 2025, 4:36 p.m. UTC
ELEVATOR_FLAG_DISABLE_WBT is only used by BFQ to disallow wbt when BFQ is
in use. The flag is set in BFQ's init(), and cleared in BFQ's exit().

Making it as request queue flag, so that we can avoid to deal with elevator
switch race. Also it isn't graceful to checking one scheduler flag in
wbt_enable_default().

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/bfq-iosched.c    | 4 ++--
 block/blk-mq-debugfs.c | 1 +
 block/blk-wbt.c        | 3 +--
 block/elevator.h       | 1 -
 include/linux/blkdev.h | 3 +++
 5 files changed, 7 insertions(+), 5 deletions(-)

Comments

Yu Kuai April 19, 2025, 8:59 a.m. UTC | #1
Hi,

在 2025/04/19 0:36, Ming Lei 写道:
> ELEVATOR_FLAG_DISABLE_WBT is only used by BFQ to disallow wbt when BFQ is
> in use. The flag is set in BFQ's init(), and cleared in BFQ's exit().
> 
> Making it as request queue flag, so that we can avoid to deal with elevator
> switch race. Also it isn't graceful to checking one scheduler flag in
> wbt_enable_default().
> 
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
>   block/bfq-iosched.c    | 4 ++--
>   block/blk-mq-debugfs.c | 1 +
>   block/blk-wbt.c        | 3 +--
>   block/elevator.h       | 1 -
>   include/linux/blkdev.h | 3 +++
>   5 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index abd80dc13562..40e4106a71e7 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -7210,7 +7210,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
>   #endif
>   
>   	blk_stat_disable_accounting(bfqd->queue);
> -	clear_bit(ELEVATOR_FLAG_DISABLE_WBT, &e->flags);
> +	blk_queue_flag_clear(QUEUE_FLAG_DISABLE_WBT, bfqd->queue);
>   	wbt_enable_default(bfqd->queue->disk);
>   
>   	kfree(bfqd);
> @@ -7397,7 +7397,7 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
>   	/* We dispatch from request queue wide instead of hw queue */
>   	blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
>   
> -	set_bit(ELEVATOR_FLAG_DISABLE_WBT, &eq->flags);
> +	blk_queue_flag_set(QUEUE_FLAG_DISABLE_WBT, q);
>   	wbt_disable_default(q->disk);
>   	blk_stat_enable_accounting(q);
>   
> diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
> index 3421b5521fe2..31e249a18407 100644
> --- a/block/blk-mq-debugfs.c
> +++ b/block/blk-mq-debugfs.c
> @@ -93,6 +93,7 @@ static const char *const blk_queue_flag_name[] = {
>   	QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
>   	QUEUE_FLAG_NAME(HCTX_ACTIVE),
>   	QUEUE_FLAG_NAME(SQ_SCHED),
> +	QUEUE_FLAG_NAME(DISABLE_WBT),
>   };
>   #undef QUEUE_FLAG_NAME
>   
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index f1754d07f7e0..29cd2e33666f 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -704,8 +704,7 @@ void wbt_enable_default(struct gendisk *disk)
>   	struct rq_qos *rqos;
>   	bool enable = IS_ENABLED(CONFIG_BLK_WBT_MQ);
>   
> -	if (q->elevator &&
> -	    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags))
> +	if (blk_queue_disable_wbt(q))
>   		enable = false;
>   
>   	/* Throttling already enabled? */
> diff --git a/block/elevator.h b/block/elevator.h
> index e4e44dfac503..e27af5492cdb 100644
> --- a/block/elevator.h
> +++ b/block/elevator.h
> @@ -121,7 +121,6 @@ struct elevator_queue
>   };
>   
>   #define ELEVATOR_FLAG_REGISTERED	0
> -#define ELEVATOR_FLAG_DISABLE_WBT	1
>   
>   /*
>    * block elevator interface
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index e39c45bc0a97..10410d9b03ad 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -644,6 +644,7 @@ enum {
>   	QUEUE_FLAG_RQ_ALLOC_TIME,	/* record rq->alloc_time_ns */
>   	QUEUE_FLAG_HCTX_ACTIVE,		/* at least one blk-mq hctx is active */
>   	QUEUE_FLAG_SQ_SCHED,		/* single queue style io dispatch */
> +	QUEUE_FLAG_DISABLE_WBT,		/* for sched to disable/enable wbt */

In fact, user can still enabel wbt by sysfs api. Perhaps change the name
to QUEUE_FLAG_WBT_DISABLE_DEFAULT?

Thanks,
Kuai

>   	QUEUE_FLAG_MAX
>   };
>   
> @@ -679,6 +680,8 @@ void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
>   #define blk_queue_sq_sched(q)	test_bit(QUEUE_FLAG_SQ_SCHED, &(q)->queue_flags)
>   #define blk_queue_skip_tagset_quiesce(q) \
>   	((q)->limits.features & BLK_FEAT_SKIP_TAGSET_QUIESCE)
> +#define blk_queue_disable_wbt(q)	\
> +	test_bit(QUEUE_FLAG_DISABLE_WBT, &(q)->queue_flags)
>   
>   extern void blk_set_pm_only(struct request_queue *q);
>   extern void blk_clear_pm_only(struct request_queue *q);
>
Nilay Shroff April 19, 2025, 2:52 p.m. UTC | #2
On 4/18/25 10:06 PM, Ming Lei wrote:
> ELEVATOR_FLAG_DISABLE_WBT is only used by BFQ to disallow wbt when BFQ is
> in use. The flag is set in BFQ's init(), and cleared in BFQ's exit().
> 
> Making it as request queue flag, so that we can avoid to deal with elevator
> switch race. Also it isn't graceful to checking one scheduler flag in
> wbt_enable_default().
> 
> Signed-off-by: Ming Lei <ming.lei@redhat.com>

Looks good to me:
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
diff mbox series

Patch

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index abd80dc13562..40e4106a71e7 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7210,7 +7210,7 @@  static void bfq_exit_queue(struct elevator_queue *e)
 #endif
 
 	blk_stat_disable_accounting(bfqd->queue);
-	clear_bit(ELEVATOR_FLAG_DISABLE_WBT, &e->flags);
+	blk_queue_flag_clear(QUEUE_FLAG_DISABLE_WBT, bfqd->queue);
 	wbt_enable_default(bfqd->queue->disk);
 
 	kfree(bfqd);
@@ -7397,7 +7397,7 @@  static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
 	/* We dispatch from request queue wide instead of hw queue */
 	blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
 
-	set_bit(ELEVATOR_FLAG_DISABLE_WBT, &eq->flags);
+	blk_queue_flag_set(QUEUE_FLAG_DISABLE_WBT, q);
 	wbt_disable_default(q->disk);
 	blk_stat_enable_accounting(q);
 
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 3421b5521fe2..31e249a18407 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -93,6 +93,7 @@  static const char *const blk_queue_flag_name[] = {
 	QUEUE_FLAG_NAME(RQ_ALLOC_TIME),
 	QUEUE_FLAG_NAME(HCTX_ACTIVE),
 	QUEUE_FLAG_NAME(SQ_SCHED),
+	QUEUE_FLAG_NAME(DISABLE_WBT),
 };
 #undef QUEUE_FLAG_NAME
 
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index f1754d07f7e0..29cd2e33666f 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -704,8 +704,7 @@  void wbt_enable_default(struct gendisk *disk)
 	struct rq_qos *rqos;
 	bool enable = IS_ENABLED(CONFIG_BLK_WBT_MQ);
 
-	if (q->elevator &&
-	    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags))
+	if (blk_queue_disable_wbt(q))
 		enable = false;
 
 	/* Throttling already enabled? */
diff --git a/block/elevator.h b/block/elevator.h
index e4e44dfac503..e27af5492cdb 100644
--- a/block/elevator.h
+++ b/block/elevator.h
@@ -121,7 +121,6 @@  struct elevator_queue
 };
 
 #define ELEVATOR_FLAG_REGISTERED	0
-#define ELEVATOR_FLAG_DISABLE_WBT	1
 
 /*
  * block elevator interface
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e39c45bc0a97..10410d9b03ad 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -644,6 +644,7 @@  enum {
 	QUEUE_FLAG_RQ_ALLOC_TIME,	/* record rq->alloc_time_ns */
 	QUEUE_FLAG_HCTX_ACTIVE,		/* at least one blk-mq hctx is active */
 	QUEUE_FLAG_SQ_SCHED,		/* single queue style io dispatch */
+	QUEUE_FLAG_DISABLE_WBT,		/* for sched to disable/enable wbt */
 	QUEUE_FLAG_MAX
 };
 
@@ -679,6 +680,8 @@  void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
 #define blk_queue_sq_sched(q)	test_bit(QUEUE_FLAG_SQ_SCHED, &(q)->queue_flags)
 #define blk_queue_skip_tagset_quiesce(q) \
 	((q)->limits.features & BLK_FEAT_SKIP_TAGSET_QUIESCE)
+#define blk_queue_disable_wbt(q)	\
+	test_bit(QUEUE_FLAG_DISABLE_WBT, &(q)->queue_flags)
 
 extern void blk_set_pm_only(struct request_queue *q);
 extern void blk_clear_pm_only(struct request_queue *q);