From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net] gso: Update tunnel segmentation to support Tx checksum offload Date: Wed, 10 Jul 2013 14:21:46 -0700 Message-ID: <1373491306.4600.17.camel@edumazet-glaptop> References: <20130710203439.14927.20911.stgit@ahduyck-hc1.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, stephen@networkplumber.org, pshelar@nicira.com, joseph.gasparakis@intel.com To: Alexander Duyck Return-path: Received: from mail-ob0-f173.google.com ([209.85.214.173]:64552 "EHLO mail-ob0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754162Ab3GJVVu (ORCPT ); Wed, 10 Jul 2013 17:21:50 -0400 Received: by mail-ob0-f173.google.com with SMTP id wc20so9098409obb.32 for ; Wed, 10 Jul 2013 14:21:49 -0700 (PDT) In-Reply-To: <20130710203439.14927.20911.stgit@ahduyck-hc1.jf.intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2013-07-10 at 13:43 -0700, Alexander Duyck wrote: > This change makes it so that the GRE and VXLAN tunnels can make use of Tx > checksum offload support provided by some drivers via the hw_enc_features. > This resolves a performance regression seen when using TSO versus just > using the Tx checksum offload. > > To achieve this it was necessary to address two items. First > netif_skb_features needed to be updated so that it would correctly handle > the Trans Ether Bridging protocol. To that end the reference to > skb->protocol was replaced with a call to skb_network_protocol. > > Second it was necessary to update the GRE and UDP tunnel segmentation > offloads so that they would reset the encapsulation bit and inner header > offsets after the offload was complete. > > Signed-off-by: Alexander Duyck > --- > > I am submitting this as a fix for 3.11 and stable, however the fix for > stable would likely need some modification since it seems that gre.c was > renamed to gre_offload.c at some point between 3.10 and 3.11. If needed > I can submit a separate patch for stable. > > net/core/dev.c | 2 +- > net/ipv4/gre_offload.c | 3 +++ > net/ipv4/udp.c | 4 +++- > 3 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index 560dafd..0419961 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -2495,7 +2495,7 @@ static netdev_features_t harmonize_features(struct sk_buff *skb, > > netdev_features_t netif_skb_features(struct sk_buff *skb) > { > - __be16 protocol = skb->protocol; > + __be16 protocol = skb_network_protocol(skb); > netdev_features_t features = skb->dev->features; > If we call skb_network_protocol() here, do we still need following tests in netif_skb_features() ? if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) { ... } else if (!vlan_tx_tag_present(skb)) { }