From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH net-next] tuntap: hardware vlan tx support Date: Tue, 23 Jul 2013 16:12:49 +0400 Message-ID: <51EE7341.4060404@cogentembedded.com> References: <1374563748-38821-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Basil Gor To: Jason Wang Return-path: In-Reply-To: <1374563748-38821-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello. On 23-07-2013 11:15, Jason Wang wrote: > Inspired by commit f09e2249c4f5c7c13261ec73f5a7807076af0c8e (macvtap: restore > vlan header on user read). This patch adds hardware vlan tx support for > tuntap. This is done by copying vlan header directly into userspace in > tun_put_user() instead of doing it through __vlan_put_tag() in > dev_hard_start_xmit(). This eliminates one unnecessary memove in s/memove/memmove/? > vlan_insert_tag() for 802.1ad and 802.1q traffic. > pktgen test shows about 20% improvement for 802.1q traffic: > Before: > 662149pps 317Mb/sec (317831520bps) errors: 0 > After: > 801033pps 384Mb/sec (384495840bps) errors: 0 > Cc: Basil Gor > Cc: Michael S. Tsirkin > Signed-off-by: Jason Wang > --- > drivers/net/tun.c | 39 +++++++++++++++++++++++++++++++++++---- > 1 files changed, 35 insertions(+), 4 deletions(-) > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index a72d141..66e265d 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c [...] > @@ -1328,11 +1330,39 @@ static ssize_t tun_put_user(struct tun_struct *tun, > total += tun->vnet_hdr_sz; > } > > - len = min_t(int, skb->len, len); > + if (!vlan_tx_tag_present(skb)) > + len = min_t(int, skb->len, len); > + else { According to Documentation/CodingStyle chapter 3, both arms of an *if* statement should have {} if one arm has it. > + int copy, ret; > + struct { > + __be16 h_vlan_proto; > + __be16 h_vlan_TCI; > + } veth; Empty line wouldn't hurt here, after declarations... > + veth.h_vlan_proto = skb->vlan_proto; > + veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); [...] WBR, Sergei