diff options
| author | Ming Lei <[email protected]> | 2021-11-17 19:55:02 +0800 |
|---|---|---|
| committer | Jens Axboe <[email protected]> | 2021-11-17 07:43:26 -0700 |
| commit | 245a489e81e13dd55ae46d27becf6d5901eb7828 (patch) | |
| tree | 486d0e18d313c6fba0f2661108c779ce6e7885ea | |
| parent | d1faacbf67b1944f0e0c618dc581d929263f6fe9 (diff) | |
block: avoid to quiesce queue in elevator_init_mq
elevator_init_mq() is only called before adding disk, when there isn't
any FS I/O, only passthrough requests can be queued, so freezing queue
plus canceling dispatch work is enough to drain any dispatch activities,
then we can avoid synchronize_srcu() in blk_mq_quiesce_queue().
Long boot latency issue can be fixed in case of lots of disks added
during booting.
Fixes: 737eb78e82d5 ("block: Delay default elevator initialization")
Reported-by: yangerkun <[email protected]>
Cc: Damien Le Moal <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
| -rw-r--r-- | block/elevator.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/block/elevator.c b/block/elevator.c index 1f39f6e8ebb9..19a78d5516ba 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -694,12 +694,18 @@ void elevator_init_mq(struct request_queue *q) if (!e) return; + /* + * We are called before adding disk, when there isn't any FS I/O, + * so freezing queue plus canceling dispatch work is enough to + * drain any dispatch activities originated from passthrough + * requests, then no need to quiesce queue which may add long boot + * latency, especially when lots of disks are involved. + */ blk_mq_freeze_queue(q); - blk_mq_quiesce_queue(q); + blk_mq_cancel_work_sync(q); err = blk_mq_init_sched(q, e); - blk_mq_unquiesce_queue(q); blk_mq_unfreeze_queue(q); if (err) { |