[Quantal][Pull Request] SRU: Fix for LP#1201869

[Chris J Arges]

BugLink: http://bugs.launchpad.net/bugs/1201869

SRU Justification:

Impact:
Users of the 3.5/3.8 kernel will have poor network throughput when using
OpenStack Neutron depending on their setup.

Fix:
These patches are all in Ubuntu-3.9.0-7.15 / v3.9-rc1:
2681128f0ced8aa4e66f221197e183cc16d244fe
8093315a91340bca52549044975d8c7f673b28a1
d0e2c55e7c940a3ee91e9e23a2683b593690f1e9

Testcase:
Setup OpenStack Neutron. Test throughput between internal and external nodes.

The following explains an example vlan+namespace configuration:
Internal Node: [10.x.x.2]->eth2.123->br123->tap123->qr-123[10.x.x.1] <--- netns: qrouter-123
netns: qrouter-123 ---> qg-234[10.x.y.1]->tap234->br234->eth2.234->External Node[10.x.y.2]
Where:
1) tap123+qr-123 and tap234+qg-234 are veth pairs
2) qr-123 and qg-234 reside inside the qrouter-123 namespace