From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Durrant Subject: [PATCH net-next v2] xen-netback: add gso_segs calculation Date: Tue, 17 Dec 2013 11:44:35 +0000 Message-ID: <1387280675-10295-1-git-send-email-paul.durrant@citrix.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Paul Durrant , Wei Liu , Ian Campbell , David Vrabel , Eric Dumazet To: , Return-path: Received: from smtp02.citrix.com ([66.165.176.63]:16075 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752418Ab3LQLoj (ORCPT ); Tue, 17 Dec 2013 06:44:39 -0500 Sender: netdev-owner@vger.kernel.org List-ID: netback already has code which parses IPv4 and v6 headers to set up checksum offsets and these are always applied to GSO packets being sent from frontends. It's therefore suboptimal that GSOs are being marked SKB_GSO_DODGY to defer the gso_segs calculation when netback already has all necessary information to hand to do the calculation. This patch adds that calculation. Signed-off-by: Paul Durrant Cc: Wei Liu Cc: Ian Campbell Cc: David Vrabel Cc: Eric Dumazet --- v2: - Fixed header size calculation drivers/net/xen-netback/netback.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 904e497..d376e27 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1043,10 +1043,7 @@ static int xenvif_set_skb_gso(struct xenvif *vif, } skb_shinfo(skb)->gso_size = gso->u.gso.size; - - /* Header must be checked, and gso_segs computed. */ - skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; - skb_shinfo(skb)->gso_segs = 0; + /* gso_segs will be calculated later */ return 0; } @@ -1582,6 +1579,20 @@ static int xenvif_tx_submit(struct xenvif *vif, int budget) skb_probe_transport_header(skb, 0); + /* If the packet is GSO then we will have just set up the + * transport header offset in checksum_setup so it's now + * straightforward to calculate gso_segs. + */ + if (skb_is_gso(skb)) { + int mss = skb_shinfo(skb)->gso_size; + int hdrlen = skb_transport_header(skb) - + skb_mac_header(skb) + + tcp_hdrlen(skb); + + skb_shinfo(skb)->gso_segs = + DIV_ROUND_UP(skb->len - hdrlen, mss); + } + vif->dev->stats.rx_bytes += skb->len; vif->dev->stats.rx_packets++; -- 1.7.10.4