[PATCH 5/6] blk-mq: don't stop queue for quiescing
From: Ming Lei <hidden>
Date: 2017-05-26 03:08:39
Also in:
dm-devel, linux-nvme, linux-scsi
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Now we use the QUIESCED flag to drain & block dispatching, not necessary to stop queue any more. Also queue can be started by other blk-mq APIs, this limits uses of blk_mq_quiesce_queue(). Now blk_mq_quiesce_queue() can be used safely and users won't worry about queue restart during quiescing. Signed-off-by: Ming Lei <redacted> --- block/blk-mq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e1fc9ab50c87..900eb91e0ece 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -168,8 +168,6 @@ void blk_mq_quiesce_queue(struct request_queue *q) unsigned int i; bool rcu = false; - __blk_mq_stop_hw_queues(q, true); - spin_lock_irq(q->queue_lock); queue_flag_set(QUEUE_FLAG_QUIESCED, q); spin_unlock_irq(q->queue_lock);
@@ -198,7 +196,12 @@ void blk_mq_unquiesce_queue(struct request_queue *q) queue_flag_clear(QUEUE_FLAG_QUIESCED, q); spin_unlock_irq(q->queue_lock); - blk_mq_start_stopped_hw_queues(q, true); + /* + * During quiescing, requests can be inserted + * to scheduler queue or sw queue, so we run + * queues for dispatching these requests. + */ + blk_mq_start_hw_queues(q); } EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
--
2.9.4