On Wed, Nov 30, 2016 at 09:18:42AM +0000, Pierre Pfister (ppfister) wrote:
> Current virtio driver advertises VERSION_1 support,
> but does not handle device's VERSION_1 support when
> sending packets (it looks for ANY_LAYOUT feature,
> which is absent).
>
> This patch enables 'can_push' in tx path when VERSION_1
> is advertised by the device.
>
> This significantly improves small packets forwarding rate
> towards devices advertising VERSION_1 feature.
>
> Signed-off-by: Pierre Pfister <ppfister at cisco.com>
>From the virtio spec point of view, that VERSION_1 implies ANY_LAYOUT,
this patch is right and I think we could apply this patch. No objections?
--yliu
> ---
> drivers/net/virtio/virtio_rxtx.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/virtio_rxtx.c
> b/drivers/net/virtio/virtio_rxtx.c
> index 22d97a4..1e5a6b9 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -1015,7 +1015,8 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> }
>
> /* optimize ring usage */
> - if (vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) &&
> + if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
> + vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
> rte_mbuf_refcnt_read(txm) == 1 &&
> RTE_MBUF_DIRECT(txm) &&
> txm->nb_segs == 1 &&
> --
> 2.7.4 (Apple Git-66)
