blk-mq-sched: allow setting of default IO scheduler
Add Kconfig entries to manage what devices get assigned an MQ
scheduler, and add a blk-mq flag for drivers to opt out of scheduling.
The latter is useful for admin type queues that still allocate a blk-mq
queue and tag set, but aren't use for normal IO.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 45e1707..fa1f861 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2285,6 +2285,14 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
mutex_unlock(&all_q_mutex);
put_online_cpus();
+ if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
+ int ret;
+
+ ret = blk_mq_sched_init(q);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
return q;
err_hctxs: