diff mbox series

[6/8] blk-ioprio: Convert from rqos policy to direct call

Message ID 20220615161616.5055-6-jack@suse.cz (mailing list archive)
State New, archived
Headers show
Series block: Fix IO priority mess | expand

Commit Message

Jan Kara June 15, 2022, 4:16 p.m. UTC 
Convert blk-ioprio handling from a rqos policy to a direct call from
blk_mq_submit_bio(). Firstly, blk-ioprio is not a much of a rqos policy
anyway, it just needs a hook in bio submission path to set the bio's IO
priority. Secondly, the rqos .track hook gets actually called too late
for blk-ioprio purposes and introducing a special rqos hook just for
blk-ioprio looks even weirder.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 block/blk-cgroup.c |  1 +
 block/blk-ioprio.c | 50 +++++-----------------------------------------
 block/blk-ioprio.h |  9 +++++++++
 block/blk-mq.c     |  8 ++++++++
 4 files changed, 23 insertions(+), 45 deletions(-)

Comments

Damien Le Moal June 16, 2022, 3:14 a.m. UTC | #1 
On 6/16/22 01:16, Jan Kara wrote:
> Convert blk-ioprio handling from a rqos policy to a direct call from
> blk_mq_submit_bio(). Firstly, blk-ioprio is not a much of a rqos policy
> anyway, it just needs a hook in bio submission path to set the bio's IO
> priority. Secondly, the rqos .track hook gets actually called too late
> for blk-ioprio purposes and introducing a special rqos hook just for
> blk-ioprio looks even weirder.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>   block/blk-cgroup.c |  1 +
>   block/blk-ioprio.c | 50 +++++-----------------------------------------
>   block/blk-ioprio.h |  9 +++++++++
>   block/blk-mq.c     |  8 ++++++++
>   4 files changed, 23 insertions(+), 45 deletions(-)
> 
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 764e740b0c0f..6906981563f8 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -1299,6 +1299,7 @@ int blkcg_init_queue(struct request_queue *q)
>   	ret = blk_iolatency_init(q);
>   	if (ret) {
>   		blk_throtl_exit(q);
> +		blk_ioprio_exit(q);
>   		goto err_destroy_all;
>   	}
>   
> diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
> index 3f605583598b..c00060a02c6e 100644
> --- a/block/blk-ioprio.c
> +++ b/block/blk-ioprio.c
> @@ -181,17 +181,12 @@ static struct blkcg_policy ioprio_policy = {
>   	.pd_free_fn	= ioprio_free_pd,
>   };
>   
> -struct blk_ioprio {
> -	struct rq_qos rqos;
> -};
> -
> -static void blkcg_ioprio_track(struct rq_qos *rqos, struct request *rq,
> -			       struct bio *bio)
> +void blkcg_set_ioprio(struct bio *bio)
>   {
>   	struct ioprio_blkcg *blkcg = ioprio_blkcg_from_bio(bio);
>   	u16 prio;
>   
> -	if (blkcg->prio_policy == POLICY_NO_CHANGE)
> +	if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE)

See my comment on patch 8.

>   		return;
>   
>   	/*
> @@ -207,49 +202,14 @@ static void blkcg_ioprio_track(struct rq_qos *rqos, struct request *rq,
>   		bio->bi_ioprio = prio;
>   }
>   
> -static void blkcg_ioprio_exit(struct rq_qos *rqos)
> +void blk_ioprio_exit(struct request_queue *q)
>   {
> -	struct blk_ioprio *blkioprio_blkg =
> -		container_of(rqos, typeof(*blkioprio_blkg), rqos);
> -
> -	blkcg_deactivate_policy(rqos->q, &ioprio_policy);
> -	kfree(blkioprio_blkg);
> +	blkcg_deactivate_policy(q, &ioprio_policy);
>   }
>   
> -static struct rq_qos_ops blkcg_ioprio_ops = {
> -	.track	= blkcg_ioprio_track,
> -	.exit	= blkcg_ioprio_exit,
> -};
> -
>   int blk_ioprio_init(struct request_queue *q)
>   {
> -	struct blk_ioprio *blkioprio_blkg;
> -	struct rq_qos *rqos;
> -	int ret;
> -
> -	blkioprio_blkg = kzalloc(sizeof(*blkioprio_blkg), GFP_KERNEL);
> -	if (!blkioprio_blkg)
> -		return -ENOMEM;
> -
> -	ret = blkcg_activate_policy(q, &ioprio_policy);
> -	if (ret) {
> -		kfree(blkioprio_blkg);
> -		return ret;
> -	}
> -
> -	rqos = &blkioprio_blkg->rqos;
> -	rqos->id = RQ_QOS_IOPRIO;
> -	rqos->ops = &blkcg_ioprio_ops;
> -	rqos->q = q;
> -
> -	/*
> -	 * Registering the rq-qos policy after activating the blk-cgroup
> -	 * policy guarantees that ioprio_blkcg_from_bio(bio) != NULL in the
> -	 * rq-qos callbacks.
> -	 */
> -	rq_qos_add(q, rqos);
> -
> -	return 0;
> +	return blkcg_activate_policy(q, &ioprio_policy);
>   }
>   
>   static int __init ioprio_init(void)
> diff --git a/block/blk-ioprio.h b/block/blk-ioprio.h
> index a7785c2f1aea..5a1eb550e178 100644
> --- a/block/blk-ioprio.h
> +++ b/block/blk-ioprio.h
> @@ -6,14 +6,23 @@
>   #include <linux/kconfig.h>
>   
>   struct request_queue;
> +struct bio;
>   
>   #ifdef CONFIG_BLK_CGROUP_IOPRIO
>   int blk_ioprio_init(struct request_queue *q);
> +void blk_ioprio_exit(struct request_queue *q);
> +void blkcg_set_ioprio(struct bio *bio);
>   #else
>   static inline int blk_ioprio_init(struct request_queue *q)
>   {
>   	return 0;
>   }
> +static inline void blk_ioprio_exit(struct request_queue *q)
> +{
> +}
> +static inline void blkcg_set_ioprio(struct bio *bio)
> +{
> +}
>   #endif
>   
>   #endif /* _BLK_IOPRIO_H_ */
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index e9bf950983c7..67a7bfa58b7c 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -42,6 +42,7 @@
>   #include "blk-stat.h"
>   #include "blk-mq-sched.h"
>   #include "blk-rq-qos.h"
> +#include "blk-ioprio.h"
>   
>   static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
>   
> @@ -2790,6 +2791,11 @@ static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
>   	return rq;
>   }
>   
> +static void bio_set_ioprio(struct bio *bio)
> +{
> +	blkcg_set_ioprio(bio);
> +}
> +
>   /**
>    * blk_mq_submit_bio - Create and send a request to block device.
>    * @bio: Bio pointer.
> @@ -2830,6 +2836,8 @@ void blk_mq_submit_bio(struct bio *bio)
>   
>   	trace_block_getrq(bio);
>   
> +	bio_set_ioprio(bio);
> +
>   	rq_qos_track(q, rq, bio);
>   
>   	blk_mq_bio_to_request(rq, bio, nr_segs);
diff mbox series

Patch

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 764e740b0c0f..6906981563f8 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1299,6 +1299,7 @@  int blkcg_init_queue(struct request_queue *q)
 	ret = blk_iolatency_init(q);
 	if (ret) {
 		blk_throtl_exit(q);
+		blk_ioprio_exit(q);
 		goto err_destroy_all;
 	}
 
diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
index 3f605583598b..c00060a02c6e 100644
--- a/block/blk-ioprio.c
+++ b/block/blk-ioprio.c
@@ -181,17 +181,12 @@  static struct blkcg_policy ioprio_policy = {
 	.pd_free_fn	= ioprio_free_pd,
 };
 
-struct blk_ioprio {
-	struct rq_qos rqos;
-};
-
-static void blkcg_ioprio_track(struct rq_qos *rqos, struct request *rq,
-			       struct bio *bio)
+void blkcg_set_ioprio(struct bio *bio)
 {
 	struct ioprio_blkcg *blkcg = ioprio_blkcg_from_bio(bio);
 	u16 prio;
 
-	if (blkcg->prio_policy == POLICY_NO_CHANGE)
+	if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE)
 		return;
 
 	/*
@@ -207,49 +202,14 @@  static void blkcg_ioprio_track(struct rq_qos *rqos, struct request *rq,
 		bio->bi_ioprio = prio;
 }
 
-static void blkcg_ioprio_exit(struct rq_qos *rqos)
+void blk_ioprio_exit(struct request_queue *q)
 {
-	struct blk_ioprio *blkioprio_blkg =
-		container_of(rqos, typeof(*blkioprio_blkg), rqos);
-
-	blkcg_deactivate_policy(rqos->q, &ioprio_policy);
-	kfree(blkioprio_blkg);
+	blkcg_deactivate_policy(q, &ioprio_policy);
 }
 
-static struct rq_qos_ops blkcg_ioprio_ops = {
-	.track	= blkcg_ioprio_track,
-	.exit	= blkcg_ioprio_exit,
-};
-
 int blk_ioprio_init(struct request_queue *q)
 {
-	struct blk_ioprio *blkioprio_blkg;
-	struct rq_qos *rqos;
-	int ret;
-
-	blkioprio_blkg = kzalloc(sizeof(*blkioprio_blkg), GFP_KERNEL);
-	if (!blkioprio_blkg)
-		return -ENOMEM;
-
-	ret = blkcg_activate_policy(q, &ioprio_policy);
-	if (ret) {
-		kfree(blkioprio_blkg);
-		return ret;
-	}
-
-	rqos = &blkioprio_blkg->rqos;
-	rqos->id = RQ_QOS_IOPRIO;
-	rqos->ops = &blkcg_ioprio_ops;
-	rqos->q = q;
-
-	/*
-	 * Registering the rq-qos policy after activating the blk-cgroup
-	 * policy guarantees that ioprio_blkcg_from_bio(bio) != NULL in the
-	 * rq-qos callbacks.
-	 */
-	rq_qos_add(q, rqos);
-
-	return 0;
+	return blkcg_activate_policy(q, &ioprio_policy);
 }
 
 static int __init ioprio_init(void)
diff --git a/block/blk-ioprio.h b/block/blk-ioprio.h
index a7785c2f1aea..5a1eb550e178 100644
--- a/block/blk-ioprio.h
+++ b/block/blk-ioprio.h
@@ -6,14 +6,23 @@ 
 #include <linux/kconfig.h>
 
 struct request_queue;
+struct bio;
 
 #ifdef CONFIG_BLK_CGROUP_IOPRIO
 int blk_ioprio_init(struct request_queue *q);
+void blk_ioprio_exit(struct request_queue *q);
+void blkcg_set_ioprio(struct bio *bio);
 #else
 static inline int blk_ioprio_init(struct request_queue *q)
 {
 	return 0;
 }
+static inline void blk_ioprio_exit(struct request_queue *q)
+{
+}
+static inline void blkcg_set_ioprio(struct bio *bio)
+{
+}
 #endif
 
 #endif /* _BLK_IOPRIO_H_ */
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e9bf950983c7..67a7bfa58b7c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -42,6 +42,7 @@ 
 #include "blk-stat.h"
 #include "blk-mq-sched.h"
 #include "blk-rq-qos.h"
+#include "blk-ioprio.h"
 
 static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
 
@@ -2790,6 +2791,11 @@  static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
 	return rq;
 }
 
+static void bio_set_ioprio(struct bio *bio)
+{
+	blkcg_set_ioprio(bio);
+}
+
 /**
  * blk_mq_submit_bio - Create and send a request to block device.
  * @bio: Bio pointer.
@@ -2830,6 +2836,8 @@  void blk_mq_submit_bio(struct bio *bio)
 
 	trace_block_getrq(bio);
 
+	bio_set_ioprio(bio);
+
 	rq_qos_track(q, rq, bio);
 
 	blk_mq_bio_to_request(rq, bio, nr_segs);