On Tue, Apr 18, 2023 at 2:53 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
>
> The previous patch, in order to facilitate review, I do not do any
> modification. This patch has made some optimization on the top.
>
> * remove some repeated logics in this function.
> * add fast check for passing without any alloc.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
> ---
> drivers/net/virtio_net.c | 29 ++++++++++++++---------------
> 1 file changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 12559062ffb6..50dc64d80d3b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1192,6 +1192,11 @@ static void *mergeable_xdp_prepare(struct virtnet_info *vi,
> */
> *frame_sz = truesize;
>
> + if (likely(headroom >= virtnet_get_headroom(vi) &&
> + (*num_buf == 1 || xdp_prog->aux->xdp_has_frags))) {
> + return page_address(*page) + offset;
> + }
> +
> /* This happens when headroom is not enough because
> * of the buffer was prefilled before XDP is set.
> * This should only happen for the first several packets.
> @@ -1200,22 +1205,15 @@ static void *mergeable_xdp_prepare(struct virtnet_info *vi,
> * support it, and we don't want to bother users who are
> * using xdp normally.
> */
> - if (!xdp_prog->aux->xdp_has_frags &&
> - (*num_buf > 1 || headroom < virtnet_get_headroom(vi))) {
> + if (!xdp_prog->aux->xdp_has_frags) {
> /* linearize data for XDP */
> xdp_page = xdp_linearize_page(rq, num_buf,
> *page, offset,
> VIRTIO_XDP_HEADROOM,
> len);
> - *frame_sz = PAGE_SIZE;
> -
> if (!xdp_page)
> return NULL;
> - offset = VIRTIO_XDP_HEADROOM;
> -
> - put_page(*page);
> - *page = xdp_page;
> - } else if (unlikely(headroom < virtnet_get_headroom(vi))) {
> + } else {
> xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
> sizeof(struct skb_shared_info));
> if (*len + xdp_room > PAGE_SIZE)
> @@ -1227,14 +1225,15 @@ static void *mergeable_xdp_prepare(struct virtnet_info *vi,
>
> memcpy(page_address(xdp_page) + VIRTIO_XDP_HEADROOM,
> page_address(*page) + offset, *len);
> - *frame_sz = PAGE_SIZE;
> - offset = VIRTIO_XDP_HEADROOM;
> -
> - put_page(*page);
> - *page = xdp_page;
> }
>
> - return page_address(*page) + offset;
> + *frame_sz = PAGE_SIZE;
> +
> + put_page(*page);
> +
> + *page = xdp_page;
> +
> + return page_address(*page) + VIRTIO_XDP_HEADROOM;
> }
>
> static struct sk_buff *receive_mergeable(struct net_device *dev,
> --
> 2.32.0.3.g01195cf9f
>
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