Re: [PATCH -next v8 2/4] block, bfq: record how many queues have pending requests

[Yu Kuai]

在 2022/06/01 16:35, Jan Kara 写道:
> On Tue 31-05-22 22:08:56, Yu Kuai wrote:
> > Prepare to refactor the counting of 'num_groups_with_pending_reqs'.
> >
> > Add a counter in bfq_group, and update it while tracking if bfqq have
> > pending requests.
> >
> > Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> Looks good, except I think that we also need to update the counters
> 'num_groups_with_pending_reqs' in bfq_move_bfqq()?
Yes, you're right. I'll do that in next version.

Thanks,
Kuai
> 								Honza
>
> > ---
> >   block/bfq-cgroup.c  |  1 +
> >   block/bfq-iosched.h |  1 +
> >   block/bfq-wf2q.c    | 12 ++++++++++--
> >   3 files changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> > index 09574af83566..0954a258a107 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;
> >   }
> > diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
> > index 3b9b1a0e7c1c..a5f7c0c1a3b3 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 12d20f26ad69..b533e17e9f0c 100644
> > --- a/block/bfq-wf2q.c
> > +++ b/block/bfq-wf2q.c
> > @@ -1651,16 +1651,24 @@ static 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