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| author | Bart Van Assche <bvanassche@acm.org> | 2019-10-25 09:50:08 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-10-25 14:12:17 -0600 |
| commit | a9a808084d6ac015ac68b4223ac5f6ef31f8076e (patch) | |
| tree | 58b254153ffb257f235cedb67f1920ec0d8e4fd9 /block | |
| parent | 48d9b0d43105e0da2b7c135eedd24e51234fb5e4 (diff) | |
| download | lwn-a9a808084d6ac015ac68b4223ac5f6ef31f8076e.tar.gz lwn-a9a808084d6ac015ac68b4223ac5f6ef31f8076e.zip | |
block: Remove the synchronize_rcu() call from __blk_mq_update_nr_hw_queues()
Since the blk_mq_{,un}freeze_queue() calls in __blk_mq_update_nr_hw_queues()
already serialize __blk_mq_update_nr_hw_queues() against
blk_mq_queue_tag_busy_iter(), the synchronize_rcu() call in
__blk_mq_update_nr_hw_queues() is not necessary. Hence remove it.
Note: the synchronize_rcu() call in __blk_mq_update_nr_hw_queues() was
introduced by commit f5bbbbe4d635 ("blk-mq: sync the update nr_hw_queues with
blk_mq_queue_tag_busy_iter"). Commit 530ca2c9bd69 ("blk-mq: Allow blocking
queue tag iter callbacks") removed the rcu_read_{,un}lock() calls that
correspond to the synchronize_rcu() call in __blk_mq_update_nr_hw_queues().
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 8538dc415499..7528678ef41f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3243,10 +3243,6 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, list_for_each_entry(q, &set->tag_list, tag_set_list) blk_mq_freeze_queue(q); /* - * Sync with blk_mq_queue_tag_busy_iter. - */ - synchronize_rcu(); - /* * Switch IO scheduler to 'none', cleaning up the data associated * with the previous scheduler. We will switch back once we are done * updating the new sw to hw queue mappings. |