Re: [PATCH v2 7/8] vsock/virtio: increase RX buffer size to 64 KiB

[Jason Wang]

On 2019/5/10 äå8:58, Stefano Garzarella wrote:
> In order to increase host -> guest throughput with large packets,
> we can use 64 KiB RX buffers.
>
> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> ---
>   include/linux/virtio_vsock.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> index 84b72026d327..5a9d25be72df 100644
> --- a/include/linux/virtio_vsock.h
> +++ b/include/linux/virtio_vsock.h
> @@ -10,7 +10,7 @@
>   #define VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE	128
>   #define VIRTIO_VSOCK_DEFAULT_BUF_SIZE		(1024 * 256)
>   #define VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE	(1024 * 256)
> -#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE	(1024 * 4)
> +#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE	(1024 * 64)
>   #define VIRTIO_VSOCK_MAX_BUF_SIZE		0xFFFFFFFFUL
>   #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE		(1024 * 64)
>   


We probably don't want such high order allocation. It's better to switch 
to use order 0 pages in this case. See add_recvbuf_big() for virtio-net. 
If we get datapath unified, we will get more stuffs set.

Thanks