Re: [PATCH net-next] tuntap: hardware vlan tx support

[Stephen Hemminger]

On Tue, 23 Jul 2013 15:15:48 +0800
Jason Wang <jasowang@xxxxxxxxxx> 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@xxxxxxxxx>
> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>


You need to make this configurable by some mechanism, since otherwise
it will break applications that expect current VLAN behavior
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/