virtio-blk is generally used in cloud computing scenarios, where the performance of virtual disks is very important. The mq-deadline scheduler has a big performance drop compared to none with single queue. In my tests, mq-deadline 4k readread iops were 270k compared to 450k for none. So here the default scheduler of virtio-blk is set to "none". Signed-off-by: Li Feng <fengli@xxxxxxxxxx> --- drivers/block/virtio_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index d53d6aa8ee69..5183ec8e00be 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1367,7 +1367,7 @@ static int virtblk_probe(struct virtio_device *vdev) vblk->tag_set.ops = &virtio_mq_ops; vblk->tag_set.queue_depth = queue_depth; vblk->tag_set.numa_node = NUMA_NO_NODE; - vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; + vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_NO_SCHED_BY_DEFAULT; vblk->tag_set.cmd_size = sizeof(struct virtblk_req) + sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; -- 2.42.0
