diff mbox series

[-next,v6,1/3] block, bfq: record how many queues are busy in bfq_group

Message ID 20220523131818.2798712-2-yukuai3@huawei.com (mailing list archive)
State New, archived
Headers show
Series support concurrent sync io for bfq on a specail occasion | expand

Commit Message

Yu Kuai May 23, 2022, 1:18 p.m. UTC 
Prepare to refactor the counting of 'num_groups_with_pending_reqs'.

Add a counter 'busy_queues' in bfq_group, and update it in
bfq_add/del_bfqq_busy().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 block/bfq-cgroup.c  |  1 +
 block/bfq-iosched.h |  2 ++
 block/bfq-wf2q.c    | 20 ++++++++++++++++++++
 3 files changed, 23 insertions(+)

Comments

Paolo Valente May 28, 2022, 8:18 a.m. UTC | #1 
> Il giorno 23 mag 2022, alle ore 15:18, Yu Kuai <yukuai3@huawei.com> ha scritto:
> 
> Prepare to refactor the counting of 'num_groups_with_pending_reqs'.
> 
> Add a counter 'busy_queues' in bfq_group, and update it in
> bfq_add/del_bfqq_busy().
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> Reviewed-by: Jan Kara <jack@suse.cz>
> ---
> block/bfq-cgroup.c  |  1 +
> block/bfq-iosched.h |  2 ++
> block/bfq-wf2q.c    | 20 ++++++++++++++++++++
> 3 files changed, 23 insertions(+)
> 
> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index 09574af83566..4d516879d9fa 100644
> --- a/block/bfq-cgroup.c
> +++ b/block/bfq-cgroup.c
> @@ -557,6 +557,7 @@ static void bfq_pd_init(struct blkg_policy_data *pd)
> 				   */
> 	bfqg->bfqd = bfqd;
> 	bfqg->active_entities = 0;
> +	bfqg->busy_queues = 0;
> 	bfqg->online = true;
> 	bfqg->rq_pos_tree = RB_ROOT;
> }
> diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
> index 978ef5d6fe6a..3847f4ab77ac 100644
> --- a/block/bfq-iosched.h
> +++ b/block/bfq-iosched.h
> @@ -906,6 +906,7 @@ struct bfq_group_data {
>  *                   are groups with more than one active @bfq_entity
>  *                   (see the comments to the function
>  *                   bfq_bfqq_may_idle()).
> + * @busy_queues: number of busy bfqqs.
>  * @rq_pos_tree: rbtree sorted by next_request position, used when
>  *               determining if two or more queues have interleaving
>  *               requests (see bfq_find_close_cooperator()).
> @@ -942,6 +943,7 @@ struct bfq_group {
> 	struct bfq_entity *my_entity;
> 
> 	int active_entities;
> +	int busy_queues;
> 
> 	struct rb_root rq_pos_tree;
> 
> diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
> index f8eb340381cf..d9ff33e0be38 100644
> --- a/block/bfq-wf2q.c
> +++ b/block/bfq-wf2q.c
> @@ -218,6 +218,16 @@ static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
> 	return false;
> }
> 
> +static void bfq_inc_busy_queues(struct bfq_queue *bfqq)
> +{
> +	bfqq_group(bfqq)->busy_queues++;
> +}
> +
> +static void bfq_dec_busy_queues(struct bfq_queue *bfqq)
> +{
> +	bfqq_group(bfqq)->busy_queues--;
> +}
> +
> #else /* CONFIG_BFQ_GROUP_IOSCHED */
> 
> static bool bfq_update_parent_budget(struct bfq_entity *next_in_service)
> @@ -230,6 +240,14 @@ static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
> 	return true;
> }
> 
> +static void bfq_inc_busy_queues(struct bfq_queue *bfqq)
> +{
> +}
> +
> +static void bfq_dec_busy_queues(struct bfq_queue *bfqq)
> +{
> +}
> +
> #endif /* CONFIG_BFQ_GROUP_IOSCHED */
> 
> /*
> @@ -1660,6 +1678,7 @@ void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
> 	bfq_clear_bfqq_busy(bfqq);
> 
> 	bfqd->busy_queues[bfqq->ioprio_class - 1]--;
> +	bfq_inc_busy_queues(bfqq);
> 

Why do you increment the number of busy queues for the group on a
del_bfqq_busy, instead of an add_bfqq_busy?

Besides, the name of the function bfq_inc_busy_queues does not mention
the target of the update, namely the group.  This creates a little
confusion at a first sight, as one sees this function invoked right
after the update of a field with the same name: bfqd->busy_queues.

> 	if (bfqq->wr_coeff > 1)
> 		bfqd->wr_busy_queues--;
> @@ -1683,6 +1702,7 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq)
> 
> 	bfq_mark_bfqq_busy(bfqq);
> 	bfqd->busy_queues[bfqq->ioprio_class - 1]++;
> +	bfq_dec_busy_queues(bfqq);

Same pair of comments as above.

Thanks,
Paolo

> 
> 	if (!bfqq->dispatched)
> 		if (bfqq->wr_coeff == 1)
> -- 
> 2.31.1
>
Yu Kuai May 28, 2022, 8:37 a.m. UTC | #2 
在 2022/05/28 16:18, Paolo Valente 写道:
> 

>> /*
>> @@ -1660,6 +1678,7 @@ void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
>> 	bfq_clear_bfqq_busy(bfqq);
>>
>> 	bfqd->busy_queues[bfqq->ioprio_class - 1]--;
>> +	bfq_inc_busy_queues(bfqq);
>>
> 
> Why do you increment the number of busy queues for the group on a
> del_bfqq_busy, instead of an add_bfqq_busy?
Hi, Paolo

You'are right, here should be bfq_dec_busy_queues()...
> 
> Besides, the name of the function bfq_inc_busy_queues does not mention
> the target of the update, namely the group.  This creates a little
> confusion at a first sight, as one sees this function invoked right
> after the update of a field with the same name: bfqd->busy_queues.
Ok, that make sense, I'll move the update of 'bfqd->busy_queues' into
the new api as well.

Thanks,
Kuai
> 
>> 	if (bfqq->wr_coeff > 1)
>> 		bfqd->wr_busy_queues--;
>> @@ -1683,6 +1702,7 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq)
>>
>> 	bfq_mark_bfqq_busy(bfqq);
>> 	bfqd->busy_queues[bfqq->ioprio_class - 1]++;
>> +	bfq_dec_busy_queues(bfqq);
> 
> Same pair of comments as above.
> 
> Thanks,
> Paolo
> 
>>
>> 	if (!bfqq->dispatched)
>> 		if (bfqq->wr_coeff == 1)
>> -- 
>> 2.31.1
>>
> 
> .
>
diff mbox series

Patch

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 09574af83566..4d516879d9fa 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -557,6 +557,7 @@  static void bfq_pd_init(struct blkg_policy_data *pd)
 				   */
 	bfqg->bfqd = bfqd;
 	bfqg->active_entities = 0;
+	bfqg->busy_queues = 0;
 	bfqg->online = true;
 	bfqg->rq_pos_tree = RB_ROOT;
 }
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index 978ef5d6fe6a..3847f4ab77ac 100644
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -906,6 +906,7 @@  struct bfq_group_data {
  *                   are groups with more than one active @bfq_entity
  *                   (see the comments to the function
  *                   bfq_bfqq_may_idle()).
+ * @busy_queues: number of busy bfqqs.
  * @rq_pos_tree: rbtree sorted by next_request position, used when
  *               determining if two or more queues have interleaving
  *               requests (see bfq_find_close_cooperator()).
@@ -942,6 +943,7 @@  struct bfq_group {
 	struct bfq_entity *my_entity;
 
 	int active_entities;
+	int busy_queues;
 
 	struct rb_root rq_pos_tree;
 
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
index f8eb340381cf..d9ff33e0be38 100644
--- a/block/bfq-wf2q.c
+++ b/block/bfq-wf2q.c
@@ -218,6 +218,16 @@  static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
 	return false;
 }
 
+static void bfq_inc_busy_queues(struct bfq_queue *bfqq)
+{
+	bfqq_group(bfqq)->busy_queues++;
+}
+
+static void bfq_dec_busy_queues(struct bfq_queue *bfqq)
+{
+	bfqq_group(bfqq)->busy_queues--;
+}
+
 #else /* CONFIG_BFQ_GROUP_IOSCHED */
 
 static bool bfq_update_parent_budget(struct bfq_entity *next_in_service)
@@ -230,6 +240,14 @@  static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
 	return true;
 }
 
+static void bfq_inc_busy_queues(struct bfq_queue *bfqq)
+{
+}
+
+static void bfq_dec_busy_queues(struct bfq_queue *bfqq)
+{
+}
+
 #endif /* CONFIG_BFQ_GROUP_IOSCHED */
 
 /*
@@ -1660,6 +1678,7 @@  void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 	bfq_clear_bfqq_busy(bfqq);
 
 	bfqd->busy_queues[bfqq->ioprio_class - 1]--;
+	bfq_inc_busy_queues(bfqq);
 
 	if (bfqq->wr_coeff > 1)
 		bfqd->wr_busy_queues--;
@@ -1683,6 +1702,7 @@  void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 
 	bfq_mark_bfqq_busy(bfqq);
 	bfqd->busy_queues[bfqq->ioprio_class - 1]++;
+	bfq_dec_busy_queues(bfqq);
 
 	if (!bfqq->dispatched)
 		if (bfqq->wr_coeff == 1)