diff options
| -rw-r--r-- | block/blk-throttle.c | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 52321a42cd7..04202617fda 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -824,7 +824,6 @@ static void throtl_add_bio_tg(struct bio *bio, struct throtl_grp *tg) /* Take a bio reference on tg */ blkg_get(tg_to_blkg(tg)); sq->nr_queued[rw]++; - tg->td->nr_queued[rw]++; throtl_enqueue_tg(tg); } @@ -855,20 +854,34 @@ static void tg_update_disptime(struct throtl_grp *tg) static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw) { struct throtl_service_queue *sq = &tg->service_queue; + struct throtl_service_queue *parent_sq = sq->parent_sq; + struct throtl_grp *parent_tg = sq_to_tg(parent_sq); struct bio *bio; bio = bio_list_pop(&sq->bio_lists[rw]); sq->nr_queued[rw]--; - /* Drop bio reference on blkg */ - blkg_put(tg_to_blkg(tg)); - - BUG_ON(tg->td->nr_queued[rw] <= 0); - tg->td->nr_queued[rw]--; throtl_charge_bio(tg, bio); - bio_list_add(&sq->parent_sq->bio_lists[rw], bio); + + /* + * If our parent is another tg, we just need to transfer @bio to + * the parent using throtl_add_bio_tg(). If our parent is + * @td->service_queue, @bio is ready to be issued. Put it on its + * bio_lists[] and decrease total number queued. The caller is + * responsible for issuing these bios. + */ + if (parent_tg) { + throtl_add_bio_tg(bio, parent_tg); + } else { + bio_list_add(&parent_sq->bio_lists[rw], bio); + BUG_ON(tg->td->nr_queued[rw] <= 0); + tg->td->nr_queued[rw]--; + } throtl_trim_slice(tg, rw); + + /* @bio is transferred to parent, drop its blkg reference */ + blkg_put(tg_to_blkg(tg)); } static int throtl_dispatch_tg(struct throtl_grp *tg) @@ -1283,6 +1296,7 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio) sq->nr_queued[READ], sq->nr_queued[WRITE]); bio_associate_current(bio); + tg->td->nr_queued[rw]++; throtl_add_bio_tg(bio, tg); throttled = true; |