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| author | Jia Cheng Hu <jia.jiachenghu@gmail.com> | 2021-01-22 19:19:44 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-01-24 18:18:24 -0700 |
| commit | d4fc3640ff361a09e359867e0bca898abd2b7ecb (patch) | |
| tree | 32cfec179ba748356172ef15519e85b23da2a3c0 /block | |
| parent | b5f74ecacc3139ef873e69acc3aba28083ecc416 (diff) | |
| download | linux-d4fc3640ff361a09e359867e0bca898abd2b7ecb.tar.bz2 | |
block, bfq: set next_rq to waker_bfqq->next_rq in waker injection
Since commit c5089591c3ba ("block, bfq: detect wakers and
unconditionally inject their I/O"), when the in-service bfq_queue, say
Q, is temporarily empty, BFQ checks whether there are I/O requests to
inject (also) from the waker bfq_queue for Q. To this goal, the value
pointed by bfqq->waker_bfqq->next_rq must be controlled. However, the
current implementation mistakenly looks at bfqq->next_rq, which
instead points to the next request of the currently served queue.
This mistake evidently causes losses of throughput in scenarios with
waker bfq_queues.
This commit corrects this mistake.
Fixes: c5089591c3ba ("block, bfq: detect wakers and unconditionally inject their I/O")
Signed-off-by: Jia Cheng Hu <jia.jiachenghu@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bfq-iosched.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index eb2ca32d5b63..fdc5e163b2fe 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4499,7 +4499,7 @@ check_queue: bfqq = bfqq->bic->bfqq[0]; else if (bfq_bfqq_has_waker(bfqq) && bfq_bfqq_busy(bfqq->waker_bfqq) && - bfqq->next_rq && + bfqq->waker_bfqq->next_rq && bfq_serv_to_charge(bfqq->waker_bfqq->next_rq, bfqq->waker_bfqq) <= bfq_bfqq_budget_left(bfqq->waker_bfqq) |