On Wed, Sep 20, 2017 at 12:49 AM, Bart Van Assche <Bart.VanAssche@xxxxxxx> wrote: > On Wed, 2017-09-20 at 00:04 +0800, Ming Lei wrote: >> Run queue at end_io is definitely wrong, because blk-mq has SCHED_RESTART >> to do that already. > > Sorry but I disagree. If SCHED_RESTART is set that causes the blk-mq core to > reexamine the software queues and the hctx dispatch list but not the requeue > list. If a block driver returns BLK_STS_RESOURCE then requests end up on the > requeue list. Hence the following code in scsi_end_request(): That doesn't need SCHED_RESTART, because it is requeue's responsibility to do that, see blk_mq_requeue_work(), which will run hw queue at the end of this func. -- Ming Lei
