On Wed 01-06-22 19:43:38, Yu Kuai wrote:
> Prepare to refactor the counting of 'num_groups_with_pending_reqs'.
>
> Add a counter in bfq_group, update it while tracking if bfqq have pending
> requests and when bfq_bfqq_move() is called.
>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> block/bfq-cgroup.c | 10 ++++++++++
> block/bfq-iosched.h | 1 +
> block/bfq-wf2q.c | 12 ++++++++++--
> 3 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index 09574af83566..88c0c320ddf3 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->num_queues_with_pending_reqs = 0;
> bfqg->online = true;
> bfqg->rq_pos_tree = RB_ROOT;
> }
> @@ -646,6 +647,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
> {
> struct bfq_entity *entity = &bfqq->entity;
> struct bfq_group *old_parent = bfqq_group(bfqq);
> + bool has_pending_reqs = false;
>
> /*
> * No point to move bfqq to the same group, which can happen when
> @@ -666,6 +668,11 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
> */
> bfqq->ref++;
>
> + if (entity->in_groups_with_pending_reqs) {
> + has_pending_reqs = true;
> + bfq_del_bfqq_in_groups_with_pending_reqs(bfqq);
> + }
> +
> /* If bfqq is empty, then bfq_bfqq_expire also invokes
> * bfq_del_bfqq_busy, thereby removing bfqq and its entity
> * from data structures related to current group. Otherwise we
> @@ -693,6 +700,9 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
> /* pin down bfqg and its associated blkg */
> bfqg_and_blkg_get(bfqg);
>
> + if (has_pending_reqs)
> + bfq_add_bfqq_in_groups_with_pending_reqs(bfqq);
> +
> if (bfq_bfqq_busy(bfqq)) {
> if (unlikely(!bfqd->nonrot_with_queueing))
> bfq_pos_tree_add_move(bfqd, bfqq);
> diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
> index 69c7d15417e5..de2446a9b7ab 100644
> --- a/block/bfq-iosched.h
> +++ b/block/bfq-iosched.h
> @@ -943,6 +943,7 @@ struct bfq_group {
> struct bfq_entity *my_entity;
>
> int active_entities;
> + int num_queues_with_pending_reqs;
>
> struct rb_root rq_pos_tree;
>
> diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
> index 5704a0315cf2..6f36f3fe5cc8 100644
> --- a/block/bfq-wf2q.c
> +++ b/block/bfq-wf2q.c
> @@ -1651,16 +1651,24 @@ void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq)
> {
> struct bfq_entity *entity = &bfqq->entity;
>
> - if (!entity->in_groups_with_pending_reqs)
> + if (!entity->in_groups_with_pending_reqs) {
> entity->in_groups_with_pending_reqs = true;
> +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> + bfqq_group(bfqq)->num_queues_with_pending_reqs++;
> +#endif
> + }
> }
>
> void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq)
> {
> struct bfq_entity *entity = &bfqq->entity;
>
> - if (entity->in_groups_with_pending_reqs)
> + if (entity->in_groups_with_pending_reqs) {
> entity->in_groups_with_pending_reqs = false;
> +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> + bfqq_group(bfqq)->num_queues_with_pending_reqs--;
> +#endif
> + }
> }
>
> /*
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
