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authorDennis Zhou (Facebook) <dennisszhou@gmail.com>2018-09-11 21:41:29 +0300
committerJens Axboe <axboe@kernel.dk>2018-09-22 05:29:06 +0300
commita7b39b4e961c4e2b3ed837803a7441a65c90ce33 (patch)
tree7dda6dda4a341971504ccd16a44dbda27d57a0f8 /block/blk-iolatency.c
parent07b05bcc3213ac9f8c28c9d835b4bf3d5798cc60 (diff)
downloadlinux-a7b39b4e961c4e2b3ed837803a7441a65c90ce33.tar.xz
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.c24
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) {