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

Jesse Gross jesse at nicira.com
Mon Feb 7 20:28:39 UTC 2011


On Mon, Feb 7, 2011 at 11:03 AM, Ben Pfaff <blp at nicira.com> wrote:
> 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.

You're right.  Fixed, thanks.

> And when after we tag the packet (when it
> is necessary) should we set the skb's vlan_tci to 0?

Yes, fixed as well.




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