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

[Yu Kuai]

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,
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);
>   	}