[ovs-discuss] adding MPTCP code breaks OVS kmod datapath creation

[Jesse Gross]

On Fri, Jan 20, 2012 at 1:50 AM, Brandon Heller <brandonh at stanford.edu> wrote:
> Hi,
>
> I'm trying to run a single system that has OVS as well as the draft Linux
> implementation of Multi-Path TCP.  Briefly, MPTCP uses multiple subflows to
> take advantage of multiple interfaces (such as WiFi + WiFi + WiMax) or
> multiple paths (within a Fat Tree in an ECMP-based data center).  The
> project is fairly young, and more details are available
> at http://mptcp.info.ucl.ac.be/.  I did not write any of this code.
>
> On an Ubuntu 3.0.0-15-generic kernel on an Ubuntu 11.10 system w/OVS
> {1.2.2/1.3.0}, I have no issues w/OVS.  When using 3.0.0-15-mptcp, which has
> about 11K lines of MPTCP-specific changes, plus a few small config changes,
> I cannot instantiate a datapath:

It's hard to say.  They made a lot of changes to their local copy of
the Linux tree and likely they did something incompatible, so it's not
really possible to support a version of Linux with arbitrary
modifications to it.

OVS is more self-contained and mainstream, so you would probably have
better luck asking them what types of modifications they have made.