Re: [PATCH v4 10/11] blk-mq: clarify dispatch may not be drained/blocked by stopping queue

2017-06-06 Thread Ming Lei
On Mon, Jun 05, 2017 at 11:55:20PM +, Bart Van Assche wrote: > On Mon, 2017-06-05 at 23:59 +0800, Ming Lei wrote: > > +/* > > + * We do not guarantee that dispatch can be drained or blocked > > + * after blk_mq_stop_hw_queue() returns. Please use > > + * blk_mq_quiesce_queue() for that

Re: [PATCH v4 10/11] blk-mq: clarify dispatch may not be drained/blocked by stopping queue

2017-06-05 Thread Bart Van Assche
On Mon, 2017-06-05 at 23:59 +0800, Ming Lei wrote: > +/* > + * We do not guarantee that dispatch can be drained or blocked > + * after blk_mq_stop_hw_queue() returns. Please use > + * blk_mq_quiesce_queue() for that requirement. > + */ Hello Ming, This is comment explains what

[PATCH v4 10/11] blk-mq: clarify dispatch may not be drained/blocked by stopping queue

2017-06-05 Thread Ming Lei
BLK_MQ_S_STOPPED may not be observed in other concurrent I/O paths, we can't guarantee that dispatching won't happen after returning from the APIs of stopping queue. So clarify the fact and avoid potential misuse. Signed-off-by: Ming Lei --- block/blk-mq.c | 10 ++