RE: bug 1918 - openmpi broken due to rdma-cm changes

Sean Hefty
2010-02-04T22:33:04Z

>OpenMPI uses rdma_bind_addr() to figure out which ip addresses are valid
>for which IB devices. This logic is now broken. Regardless of whether
>OpenMPI should use another method for determining which IP address
>belong to which interfaces, we should probably rethink whether we're
>breaking rdma-cm semantics in a bad way on a point release.

The changes to the rdma_cm have been merged upstream. These were fixes
specifically to enable using the loopback address with RDMA devices.

At first thought, we can extend enum ib_device_cap_flags to indicate if a device
supports loopback capabilities or not. The rdma_cm could then skip over such
devices when dealing with a loopback address.

- Sean