Commit d1e9aa9c authored by Joseph Qi's avatar Joseph Qi Committed by Michael S. Tsirkin
Browse files

virtio-blk: support per-device queue depth 



module parameter 'virtblk_queue_depth' was firstly introduced for
testing/benchmarking purposes described in commit fc4324b4
("virtio-blk: base queue-depth on virtqueue ringsize or module param").
And currently 'virtblk_queue_depth' is used as a saved value for the
first probed device.
Since we have different virtio-blk devices which have different
capabilities, it requires that we support per-device queue depth instead
of per-module. So defaultly use vq free elements if module parameter
'virtblk_queue_depth' is not set.

Signed-off-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/1611307306-71067-1-git-send-email-joseph.qi@linux.alibaba.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 1628c687

drivers/block/virtio_blk.c

+7 −4
Original line number Diff line number Diff line
@@ -705,6 +705,7 @@ static int virtblk_probe(struct virtio_device *vdev) 
	u32 v, blk_size, max_size, sg_elems, opt_io_size;

	u16 min_io_size;

	u8 physical_block_exp, alignment_offset;

	unsigned int queue_depth;



	if (!vdev->config->get) {

		dev_err(&vdev->dev, "%s failure: config access disabled\n",
@@ -756,16 +757,18 @@ static int virtblk_probe(struct virtio_device *vdev) 
	}



	/* Default queue sizing is to fill the ring. */

	if (!virtblk_queue_depth) {

		virtblk_queue_depth = vblk->vqs[0].vq->num_free;

	if (likely(!virtblk_queue_depth)) {

		queue_depth = vblk->vqs[0].vq->num_free;

		/* ... but without indirect descs, we use 2 descs per req */

		if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))

			virtblk_queue_depth /= 2;

			queue_depth /= 2;

	} else {

		queue_depth = virtblk_queue_depth;

	}



	memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));

	vblk->tag_set.ops = &virtio_mq_ops;

	vblk->tag_set.queue_depth = virtblk_queue_depth;

	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.cmd_size =