# Re: \[RFC PATCH 2/2\] block: virtio-blk: support multi virt queues per virtio-blk device

- From: Stefan Hajnoczi \<hidden\>
- Date: 2014-06-17 02:40:58 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2014/06/4274613
- Thread: https://ratatoskr.run/linux-api/2014/06/4273166/t.md

```text
On Sat, Jun 14, 2014 at 1:29 AM, Ming Lei [ref] wrote:
> Firstly this patch supports more than one virtual queues for virtio-blk
> device.
>
> Secondly this patch maps the virtual queue to blk-mq's hardware queue.
>
> With this approach, both scalability and performance problem can be improved.
>
> Signed-off-by: Ming Lei <redacted>
> ---
>  drivers/block/virtio_blk.c |   75 ++++++++++++++++++++++++++++++++------------
>  1 file changed, 55 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index f63d358..e0d077d 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -16,6 +16,8 @@
>
>  #define PART_BITS 4
>
> +#define MAX_NUM_VQ 16

It would be nice to allocate virtqueues dynamically instead of
hardcoding the limit.  virtio-scsi also allocates virtqueues
dynamically.

Stefan
```