[ovs-dev] [PATCH 4/4] datapath: Add module parameter to allow TSO with vlans.

Ben Pfaff blp at nicira.com
Mon Feb 7 19:03:56 UTC 2011

On Sat, Feb 05, 2011 at 04:14:49PM -0800, Jesse Gross wrote:
> We currently perform GSO on packets before adding a vlan tag,
> which is reliable but hurts performance.  Even NICs that support
> TSO on vlan tagged packets typically expect vlan acceleration to
> be used.  Before 2.6.37 we can't use vlan acceleration and must
> place the tag in the packet itself, which is risky when used with
> TSO.  However, if the driver is known to work with internally
> tagged packets and TSO this exposes a module parameter to enable it.
> Signed-off-by: Jesse Gross <jesse at nicira.com>

In netdev_send(), when pskb_expand_head() fails I think we need a
kfree_skb() before returning.  And when after we tag the packet (when it
is necessary) should we set the skb's vlan_tci to 0?

Acked-by: Ben Pfaff <blp at nicira.com>

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