[ofa-general] [PATCH v2 RESEND] rdma_cm: Add debugfs entries to monitor rdma_cm connections

[Roland Dreier]

 > It seems like a dead and and there won't be a consensus on how to implement this. 
 > Without disrespecting Jason's opinion I still would like to see this patch get in.
 > What's the convention in such cases?

In general when the maintainer (ie me) is not convinced about a patch
and there is not a strong consensus from others then we don't merge the
patch.  And in this particular case I find myself agreeing more and more
with Jason.

The big issue seems to be your requirement that this debugging work with
"cat" with no other tools needed; however sticking stuff in debugfs
means also that "mount" as root is needed.  And to be honest, putting
hard-to-extend and hard-to-parse text blobs in debugfs does seem much
less useful than a netlink interface (which is much easier to use
programmatically and allows for extension), even if netlink requires
someone to write a (simple) userspace tool to dump information.  OFED
gives you a short-term way to make sure that tool is available to your
users, and longer-term integrating with existing tools will be easier if
you use netlink.

Really, is being able to dump with "cat" so important?  Even if it is, I
would still prefer to see the infrastructure for doing this properly
through netlink go in first, and add the debugfs support on top of that.

As an aside, I think adding ftrace events support to the cma might be
useful for debugging as well.

 - R.