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| author | Ming Lei <ming.lei@redhat.com> | 2021-05-14 10:20:52 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-05-14 08:59:08 -0600 |
| commit | 03f26d8f11403295de445b6e4e0e57ac57755791 (patch) | |
| tree | 1957af73deaa32dff92ead193f1490b798f47f90 | |
| parent | 6bdf2fbc48f104a84606f6165aa8a20d9a7d9074 (diff) | |
| download | linux-stable-03f26d8f11403295de445b6e4e0e57ac57755791.tar.gz linux-stable-03f26d8f11403295de445b6e4e0e57ac57755791.tar.bz2 linux-stable-03f26d8f11403295de445b6e4e0e57ac57755791.zip | |
blk-mq: plug request for shared sbitmap
In case of shared sbitmap, request won't be held in plug list any more
sine commit 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per
tagset"), this way makes request merge from flush plug list & batching
submission not possible, so cause performance regression.
Yanhui reports performance regression when running sequential IO
test(libaio, 16 jobs, 8 depth for each job) in VM, and the VM disk
is emulated with image stored on xfs/megaraid_sas.
Fix the issue by recovering original behavior to allow to hold request
in plug list.
Cc: Yanhui Ma <yama@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: kashyap.desai@broadcom.com
Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210514022052.1047665-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-mq.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 466676bc2f0b..28ef0248efba 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2232,8 +2232,9 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio) /* Bypass scheduler for flush requests */ blk_insert_flush(rq); blk_mq_run_hw_queue(data.hctx, true); - } else if (plug && (q->nr_hw_queues == 1 || q->mq_ops->commit_rqs || - !blk_queue_nonrot(q))) { + } else if (plug && (q->nr_hw_queues == 1 || + blk_mq_is_sbitmap_shared(rq->mq_hctx->flags) || + q->mq_ops->commit_rqs || !blk_queue_nonrot(q))) { /* * Use plugging if we have a ->commit_rqs() hook as well, as * we know the driver uses bd->last in a smart fashion. |