On 2022/10/22 5:22, Bart Van Assche wrote:
On 10/20/22 03:56, Christoph Hellwig wrote:
From: Chao Leng <lengchao@xxxxxxxxxx>
Drivers that have shared tagsets may need to quiesce potentially a lot
of request queues that all share a single tagset (e.g. nvme). Add an
interface to quiesce all the queues on a given tagset. This interface is
useful because it can speedup the quiesce by doing it in parallel.
Because some queues should not need to be quiesced(e.g. nvme connect_q)
should not need -> do not have
when quiesce the tagset. So introduce QUEUE_FLAG_SKIP_TAGSET_QUIESCE to
quiesce -> quiescing
. So -> ,
tagset quiesce interface to skip the queue.
Hi Christoph,
Are there any drivers that may call blk_mq_quiesce_tagset() concurrently from two different threads? blk_mq_quiesce_queue() supports this but blk_mq_quiesce_tagset() cannot support this because of the mechanism used to mark request queues that should be skipped (queue flag).
blk_mq_quiesce_tagset() support concurrency. blk_mq_quiesce_tagset() just
check the flag(QUEUE_FLAG_SKIP_TAGSET_QUIESCE), it has no impact on concurrency.
