Messages in this thread | | | Date | Tue, 23 Jul 2013 18:27:35 +0300 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH net-next] tuntap: hardware vlan tx support |
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On Tue, Jul 23, 2013 at 08:17:27AM -0700, Stephen Hemminger wrote: > On Tue, 23 Jul 2013 15:15:48 +0800 > Jason Wang <jasowang@redhat.com> 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 > > 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 <basil.gor@gmail.com> > > Cc: Michael S. Tsirkin <mst@redhat.com> > > Signed-off-by: Jason Wang <jasowang@redhat.com> > > > You need to make this configurable by some mechanism, since otherwise > it will break applications that expect current VLAN behavior
I don't think there's a behavior change: vlan is still linearized into the buffer. It's just done more efficiently.
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