[openib-general] [PATCH] IPoIB CM Experimental support

[Roland Dreier]

 > I know. Still, this only happens if you enable CM. Maybe it will help
 > to mention this in the comment in KConfig? Log a message as well?

Logging a message might help a tiny bit.  But the Kconfig help text is
useless -- most naive users will be running distro kernels or OFED,
which I assume will enable CM by default.

 > I have a notion that once this code is upstream we can work on
 > ways to teach kernel about net devices where MTU changes dynamically.
 > Or possibly, some tricks with icmp can make it work.

I think it would be better to use ethtool or something similar to
explicitly enable CM.  At least until there's a way to make multicast
work on an interface using CM.