Re: [PATCH] block, bfq: do the all counting of pending-request if CONFIG_BFQ_GROUP_IOSCHED is enabled

[Yuwei Guan <ssawgyw@xxxxxxxxx>]

On 2022/11/10 17:28, Yu Kuai wrote:
> Hi,
>
> 在 2022/11/09 21:29, Yuwei Guan 写道:
> > The 'bfqd->num_groups_with_pending_reqs' is used when
> > CONFIG_BFQ_GROUP_IOSCHED is enabled, so let the variables and processes
> > take effect when ONFIG_BFQ_GROUP_IOSCHED is enabled.
> >
> > Cc: Yu Kuai <yukuai3@xxxxxxxxxx>
> > Signed-off-by: Yuwei Guan <Yuwei.Guan@xxxxxxxxxxxxx>
> > ---
> >   block/bfq-iosched.c |  5 ++++-
> >   block/bfq-iosched.h |  6 ++++++
> >   block/bfq-wf2q.c    | 10 ++++++----
> >   3 files changed, 16 insertions(+), 5 deletions(-)
> >
> > diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> > index 2381cf220ba2..5a648433fd89 100644
> > --- a/block/bfq-iosched.c
> > +++ b/block/bfq-iosched.c
> > @@ -6192,8 +6192,9 @@ static void bfq_completed_request(struct 
> > bfq_queue *bfqq, struct bfq_data *bfqd)
> >            * mechanism).
> >            */
> >           bfqq->budget_timeout = jiffies;
> > -
> > +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >           bfq_del_bfqq_in_groups_with_pending_reqs(bfqq);
> > +#endif
> >           bfq_weights_tree_remove(bfqq);
> >       }
>
> Thanks for the patch, this make sense. However, I prefer to
> declare a empty function if the config is disabled instead of adding
> "#ifdef" everywhere the function is called.

Thanks a lot for reviewing. Get it, I will send v1 soon.

> Thanks,
> Kuai
> >   @@ -7051,7 +7052,9 @@ static int bfq_init_queue(struct 
> > request_queue *q, struct elevator_type *e)
> >       bfqd->idle_slice_timer.function = bfq_idle_slice_timer;
> >         bfqd->queue_weights_tree = RB_ROOT_CACHED;
> > +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >       bfqd->num_groups_with_pending_reqs = 0;
> > +#endif
> >         INIT_LIST_HEAD(&bfqd->active_list);
> >       INIT_LIST_HEAD(&bfqd->idle_list);
> > diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
> > index 9fa89577322d..d6b9fad28a3b 100644
> > --- a/block/bfq-iosched.h
> > +++ b/block/bfq-iosched.h
> > @@ -197,8 +197,10 @@ struct bfq_entity {
> >       /* flag, set to request a weight, ioprio or ioprio_class 
> > change  */
> >       int prio_changed;
> >   +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >       /* flag, set if the entity is counted in 
> > groups_with_pending_reqs */
> >       bool in_groups_with_pending_reqs;
> > +#endif
> >         /* last child queue of entity created (for non-leaf entities) */
> >       struct bfq_queue *last_bfqq_created;
> > @@ -491,6 +493,7 @@ struct bfq_data {
> >        */
> >       struct rb_root_cached queue_weights_tree;
> >   +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >       /*
> >        * Number of groups with at least one process that
> >        * has at least one request waiting for completion. Note that
> > @@ -538,6 +541,7 @@ struct bfq_data {
> >        * with no request waiting for completion.
> >        */
> >       unsigned int num_groups_with_pending_reqs;
> > +#endif
> >         /*
> >        * Per-class (RT, BE, IDLE) number of bfq_queues containing
> > @@ -1074,8 +1078,10 @@ void bfq_requeue_bfqq(struct bfq_data *bfqd, 
> > struct bfq_queue *bfqq,
> >                 bool expiration);
> >   void bfq_del_bfqq_busy(struct bfq_queue *bfqq, bool expiration);
> >   void bfq_add_bfqq_busy(struct bfq_queue *bfqq);
> > +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >   void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
> >   void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
> > +#endif
> >     /* --------------- end of interface of B-WF2Q+ ---------------- */
> >   diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
> > index b02b53658ed4..a29187ecdc39 100644
> > --- a/block/bfq-wf2q.c
> > +++ b/block/bfq-wf2q.c
> > @@ -1610,16 +1610,15 @@ void bfq_requeue_bfqq(struct bfq_data *bfqd, 
> > struct bfq_queue *bfqq,
> >                       bfqq == bfqd->in_service_queue, expiration);
> >   }
> >   +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >   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) {
> >           entity->in_groups_with_pending_reqs = true;
> > -#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >           if (!(bfqq_group(bfqq)->num_queues_with_pending_reqs++))
> >               bfqq->bfqd->num_groups_with_pending_reqs++;
> > -#endif
> >       }
> >   }
> >   @@ -1629,12 +1628,11 @@ void 
> > bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq)
> >         if (entity->in_groups_with_pending_reqs) {
> >           entity->in_groups_with_pending_reqs = false;
> > -#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >           if (!(--bfqq_group(bfqq)->num_queues_with_pending_reqs))
> >               bfqq->bfqd->num_groups_with_pending_reqs--;
> > -#endif
> >       }
> >   }
> > +#endif
> >     /*
> >    * Called when the bfqq no longer has requests pending, remove it from
> > @@ -1659,7 +1657,9 @@ void bfq_del_bfqq_busy(struct bfq_queue *bfqq, 
> > bool expiration)
> >       bfq_deactivate_bfqq(bfqd, bfqq, true, expiration);
> >         if (!bfqq->dispatched) {
> > +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >           bfq_del_bfqq_in_groups_with_pending_reqs(bfqq);
> > +#endif
> >           /*
> >            * Next function is invoked last, because it causes bfqq to be
> >            * freed. DO NOT use bfqq after the next function invocation.
> > @@ -1683,7 +1683,9 @@ void bfq_add_bfqq_busy(struct bfq_queue *bfqq)
> >       bfqd->busy_queues[bfqq->ioprio_class - 1]++;
> >         if (!bfqq->dispatched) {
> > +#ifdef CONFIG_BFQ_GROUP_IOSCHED
> >           bfq_add_bfqq_in_groups_with_pending_reqs(bfqq);
> > +#endif
> >           if (bfqq->wr_coeff == 1)
> >               bfq_weights_tree_add(bfqq);
> >       }