diff --git a/block/elevator.c b/block/elevator.c index 2a525863d4e92ab9b19bcb1b40d923365e5bbdef..4ce6b22813a14690f4bb70795712111fec02e704 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -624,6 +624,9 @@ static inline bool elv_support_iosched(struct request_queue *q) */ static struct elevator_type *elevator_get_default(struct request_queue *q) { + if (q->tag_set && q->tag_set->flags & BLK_MQ_F_NO_SCHED_BY_DEFAULT) + return NULL; + if (q->nr_hw_queues != 1) return NULL; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 92bbc9a72355abcc1c6af6ed6b6842e0382fa770..eee2c8a166015c419d0862786124b7a7591923e0 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -399,7 +399,13 @@ enum { BLK_MQ_F_STACKING = 1 << 2, BLK_MQ_F_TAG_HCTX_SHARED = 1 << 3, BLK_MQ_F_BLOCKING = 1 << 5, + /* Do not allow an I/O scheduler to be configured. */ BLK_MQ_F_NO_SCHED = 1 << 6, + /* + * Select 'none' during queue registration in case of a single hwq + * or shared hwqs instead of 'mq-deadline'. + */ + BLK_MQ_F_NO_SCHED_BY_DEFAULT = 1 << 7, BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, BLK_MQ_F_ALLOC_POLICY_BITS = 1,