diff options
| author | Dennis Zhou (Facebook) <dennisszhou@gmail.com> | 2018-09-11 20:41:29 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-09-22 04:29:06 +0200 |
| commit | a7b39b4e961c4e2b3ed837803a7441a65c90ce33 (patch) | |
| tree | 7dda6dda4a341971504ccd16a44dbda27d57a0f8 /block/blk-iolatency.c | |
| parent | blkcg: convert blkg_lookup_create to find closest blkg (diff) | |
| download | linux-a7b39b4e961c4e2b3ed837803a7441a65c90ce33.tar.xz linux-a7b39b4e961c4e2b3ed837803a7441a65c90ce33.zip | |
blkcg: always associate a bio with a blkg
Previously, blkg's were only assigned as needed by blk-iolatency and
blk-throttle. bio->css was also always being associated while blkg was
being looked up and then thrown away in blkcg_bio_issue_check.
This patch begins the cleanup of bio->css and bio->bi_blkg by always
associating a blkg in blkcg_bio_issue_check. This tries to create the
blkg, but if it is not possible, falls back to using the root_blkg of
the request_queue. Therefore, a bio will always be associated with a
blkg. The duplicate association logic is removed from blk-throttle and
blk-iolatency.
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 24 |
1 files changed, 2 insertions, 22 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index ffde3ab9f84c..7337fbc7f850 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -392,34 +392,14 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio, spinlock_t *lock) { struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos); - struct blkcg *blkcg; - struct blkcg_gq *blkg; - struct request_queue *q = rqos->q; + struct blkcg_gq *blkg = bio->bi_blkg; bool issue_as_root = bio_issue_as_root_blkg(bio); if (!blk_iolatency_enabled(blkiolat)) return; - rcu_read_lock(); - bio_associate_blkcg(bio, NULL); - blkcg = bio_blkcg(bio); - blkg = blkg_lookup(blkcg, q); - if (unlikely(!blkg)) { - if (!lock) - spin_lock_irq(q->queue_lock); - blkg = __blkg_lookup_create(blkcg, q); - if (IS_ERR(blkg)) - blkg = NULL; - if (!lock) - spin_unlock_irq(q->queue_lock); - } - if (!blkg) - goto out; - bio_issue_init(&bio->bi_issue, bio_sectors(bio)); - bio_associate_blkg(bio, blkg); -out: - rcu_read_unlock(); + while (blkg && blkg->parent) { struct iolatency_grp *iolat = blkg_to_lat(blkg); if (!iolat) { |