Re: [PATCH RFC] virtio-blk: support per-device queue depth

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 2021/1/18 上午11:58, Joseph Qi wrote:
module parameter 'virtblk_queue_depth' was firstly introduced for
testing/benchmarking purposes described in commit fc4324b4597c
("virtio-blk: base queue-depth on virtqueue ringsize or module param").
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.


I wonder if it's better to use sysfs instead (or whether it has already had something like this in the blocker layer).

Thanks



Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
---
  drivers/block/virtio_blk.c | 12 +++++++-----
  1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 145606d..f83a417 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -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",
@@ -755,17 +756,18 @@ static int virtblk_probe(struct virtio_device *vdev)
  		goto out_free_vq;
  	}
- /* 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 =

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization




[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux