How to switch Connected and Datagram IPoIB modes - FreeBSD 9.1

Garrett Cooper yanegomi at
Sun Jun 9 18:51:01 UTC 2013

On Sun, Jun 9, 2013 at 4:11 AM, Alex Liptsin <alexl at> wrote:

> Hello.
> Can I edit IPOIB_CM option manually, during the runtime or I need to
> compile the Kernel each time I what to switch UD an CM mode?
> options        IPOIB_CM        # Use connect mode ipoib

The way to solve this would be to add either a tunable/sysctl (if you can
modify this at runtime), or just a tunable (if you can modify this only at
load time). That way you could switch between modes without having to
recompile the kernel (and optionally without a reboot if you unload the
module and reload it).

This ASSUMES that no driver structures or code paths that are being
modified in such a way that you _HAVE_ to have this option compiled into
the kernel.

And yeah.. I'm not an expert in Infiniband -- other people on my team are
-- so my recommendation is generic because I haven't read and fully
digested the IB spec.


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