Re: [PATCH 05/12] blkcg: consolidate bio_issue_init to be a part of core

[Liu Bo]

On Thu, Sep 6, 2018 at 2:10 PM, Dennis Zhou <dennisszhou@xxxxxxxxx> wrote:
> From: "Dennis Zhou (Facebook)" <dennisszhou@xxxxxxxxx>
>
> bio_issue_init among other things initializes the timestamp for an IO.
> Rather than have this logic handled by policies, this consolidates it to
> be on the init paths (normal, clone, bounce clone).
>

Looks good.
Reviewed-by: Liu Bo <bo.liu@xxxxxxxxxxxxxxxxx>

thanks,
liubo

> Signed-off-by: Dennis Zhou <dennisszhou@xxxxxxxxx>
> Acked-by: Tejun Heo <tj@xxxxxxxxxx>
> ---
> v2: Association path consolidation was moved to the prior patch.
>
>  block/bio.c                | 2 ++
>  block/blk-iolatency.c      | 2 --
>  block/blk-throttle.c       | 8 --------
>  block/bounce.c             | 2 ++
>  include/linux/blk-cgroup.h | 9 +++++++++
>  5 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/block/bio.c b/block/bio.c
> index b2b3fddfcd6f..a05997bdb967 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -610,6 +610,8 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
>         bio->bi_io_vec = bio_src->bi_io_vec;
>
>         bio_clone_blkcg_association(bio, bio_src);
> +
> +       blkcg_bio_issue_init(bio);
>  }
>  EXPORT_SYMBOL(__bio_clone_fast);
>
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index 79a7549e2062..9d7052bad6f7 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -401,8 +401,6 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio,
>         if (!blk_iolatency_enabled(blkiolat))
>                 return;
>
> -       bio_issue_init(&bio->bi_issue, bio_sectors(bio));
> -
>         while (blkg && blkg->parent) {
>                 struct iolatency_grp *iolat = blkg_to_lat(blkg);
>                 if (!iolat) {
> diff --git a/block/blk-throttle.c b/block/blk-throttle.c
> index b7b5cc4defc2..f2b355338894 100644
> --- a/block/blk-throttle.c
> +++ b/block/blk-throttle.c
> @@ -2126,13 +2126,6 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td)
>  }
>  #endif
>
> -static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio)
> -{
> -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
> -       bio_issue_init(&bio->bi_issue, bio_sectors(bio));
> -#endif
> -}
> -
>  bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
>                     struct bio *bio)
>  {
> @@ -2156,7 +2149,6 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
>         if (unlikely(blk_queue_bypass(q)))
>                 goto out_unlock;
>
> -       blk_throtl_assoc_bio(tg, bio);
>         blk_throtl_update_idletime(tg);
>
>         sq = &tg->service_queue;
> diff --git a/block/bounce.c b/block/bounce.c
> index bc63b3a2d18c..7a08703b1204 100644
> --- a/block/bounce.c
> +++ b/block/bounce.c
> @@ -259,6 +259,8 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
>
>         bio_clone_blkcg_association(bio, bio_src);
>
> +       blkcg_bio_issue_init(bio);
> +
>         return bio;
>  }
>
> diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
> index 6e33ad1d92b4..a6b6e741a75e 100644
> --- a/include/linux/blk-cgroup.h
> +++ b/include/linux/blk-cgroup.h
> @@ -897,6 +897,12 @@ static inline bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg
>                                   struct bio *bio) { return false; }
>  #endif
>
> +
> +static inline void blkcg_bio_issue_init(struct bio *bio)
> +{
> +       bio_issue_init(&bio->bi_issue, bio_sectors(bio));
> +}
> +
>  static inline bool blkcg_bio_issue_check(struct request_queue *q,
>                                          struct bio *bio)
>  {
> @@ -922,6 +928,8 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q,
>                 blkg_rwstat_add(&blkg->stat_ios, bio->bi_opf, 1);
>         }
>
> +       blkcg_bio_issue_init(bio);
> +
>         rcu_read_unlock();
>         return !throtl;
>  }
> @@ -1034,6 +1042,7 @@ static inline void blk_put_rl(struct request_list *rl) { }
>  static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { }
>  static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; }
>
> +static inline void blkcg_bio_issue_init(struct bio *bio) { }
>  static inline bool blkcg_bio_issue_check(struct request_queue *q,
>                                          struct bio *bio) { return true; }
>
> --
> 2.17.1
>