| Message ID | 1440658386-9544-1-git-send-email-jasowang@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Jason Wang <jasowang@redhat.com> Date: Thu, 27 Aug 2015 14:53:06 +0800 > Usually an skb does not have up to MAX_SKB_FRAGS frags. So no need to > initialize the unuse part of sg. This patch initialize the sg based on > the real number it will used: > > - during xmit, it could be inferred from nr_frags and can_push. > - for small receive buffer, it will also be 2. > > Cc: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> This looks fine, thanks Jason. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 53f5660..c006ae4 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -540,7 +540,7 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, skb_put(skb, GOOD_PACKET_LEN); hdr = skb_vnet_hdr(skb); - sg_init_table(rq->sg, MAX_SKB_FRAGS + 2); + sg_init_table(rq->sg, 2); sg_set_buf(rq->sg, hdr, vi->hdr_len); skb_to_sgvec(skb, rq->sg + 1, 0, skb->len); @@ -893,7 +893,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) if (vi->mergeable_rx_bufs) hdr->num_buffers = 0; - sg_init_table(sq->sg, MAX_SKB_FRAGS + 2); + sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2)); if (can_push) { __skb_push(skb, hdr_len); num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
Usually an skb does not have up to MAX_SKB_FRAGS frags. So no need to initialize the unuse part of sg. This patch initialize the sg based on the real number it will used: - during xmit, it could be inferred from nr_frags and can_push. - for small receive buffer, it will also be 2. Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/net/virtio_net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)