On Wed, Oct 30, 2024 at 03:46:52PM +0100, Christoph Hellwig wrote: > On Wed, Oct 30, 2024 at 08:42:37PM +0800, Ming Lei wrote: > > --- a/block/elevator.c > > +++ b/block/elevator.c > > @@ -598,13 +598,17 @@ void elevator_init_mq(struct request_queue *q) > > * drain any dispatch activities originated from passthrough > > * requests, then no need to quiesce queue which may add long boot > > * latency, especially when lots of disks are involved. > > + * > > + * Disk isn't added yet, so verifying queue lock only manually. > > */ > > - blk_mq_freeze_queue(q); > > + blk_mq_freeze_queue_non_owner(q); > > + blk_freeze_acquire_lock(q, true, false); > > blk_mq_cancel_work_sync(q); > > > > err = blk_mq_init_sched(q, e); > > > > - blk_mq_unfreeze_queue(q); > > + blk_unfreeze_release_lock(q, true, false); > > + blk_mq_unfreeze_queue_non_owner(q); > > Why do we need to free at all from the add_disk case? The passthrough > command should never hit the elevator, or am I missing something? In theory the queue needn't to be frozen here, but both FS IO and PT req share common blk-mq code, in which q->elevator is often referenced. Thanks, Ming
