diff options
| author | Dennis Zhou <dennis@kernel.org> | 2018-12-05 12:10:28 -0500 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-07 22:26:36 -0700 |
| commit | beea9da07d8a6228a7e4a31a83f9478d513bf03f (patch) | |
| tree | 263661b03b835c4715fbeb97c2bdbd0331233001 /block/blk-iolatency.c | |
| parent | b978962ad4f7f9c06e5aa07b2a9b22f6d600456c (diff) | |
blkcg: convert blkg_lookup_create() to find closest blkg
There are several scenarios where blkg_lookup_create() can fail such as
the blkcg dying, request_queue is dying, or simply being OOM. Most
handle this by simply falling back to the q->root_blkg and calling it a
day.
This patch implements the notion of closest blkg. During
blkg_lookup_create(), if it fails to create, return the closest blkg
found or the q->root_blkg. blkg_try_get_closest() is introduced and used
during association so a bio is always attached to a blkg.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index e6f68f15dee9..46e86c34cf79 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -483,21 +483,11 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio) rcu_read_lock(); bio_associate_blkcg(bio, NULL); blkcg = bio_blkcg(bio); - blkg = blkg_lookup(blkcg, q); - if (unlikely(!blkg)) { - spin_lock_irq(&q->queue_lock); - blkg = __blkg_lookup_create(blkcg, q); - if (IS_ERR(blkg)) - blkg = NULL; - spin_unlock_irq(&q->queue_lock); - } - if (!blkg) - goto out; - + blkg = blkg_lookup_create(blkcg, q); 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) { |