It is definitely true that if both libnl v1 and libnl v3 (also known as "libnl3", even though libnl v1 is known as "libnl") are present in the same process, Random Bad Things will happen. This is due to unfortunate choices that the netlink library authors and/or packagers made.
>From what I have heard, the world is moving to libnl3, but this is a change >that will take time. The usnic BTL uses libfabric; the usnic provider in libfabric can use either libnl or libnl3. I don't know what else in OFED uses libnl -- perhaps IBoIP (aka RoCE)? We've talked about this internally. But sadly, we haven't come up with a good+reliable way to run-time detect if both libnl and libnl3 are present in the same process (e.g., if some of OMPI's dependent libraries pull them both in). We could try to opal_dl_open() NULL and them look for symbols that are unique to libnl and libnl3, but a) when to do that, and b) it's not guaranteed to work in all cases. > On Aug 24, 2015, at 7:36 AM, Gilles Gouaillardet > <gilles.gouaillar...@gmail.com> wrote: > > Folks, > > I recently installed libnl3-devel rpm on my centos 7 box, reconfigured and > recompiled ompi, and ompi_info now crashes. > > it seems the root cause is an obscure conflict between libnl and libnl3. > libnl is indirectly required by the common_verbs mac (OFED libraries do need > it) and libnl3 is required by reachable_netlink mca when available. > > currently, there are two workarounds available > 1. uninstall libln3-devel rpm, so reachable_netlink mca uses libnl > 2. configure with --without-verbs so no mac requires libnl > > right now, my best bet would be not to use libnl3 when configure'd with > --verbs and OFED is available. > > any thoughts ? > > Cheers, > > Gilles > > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/08/17812.php -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
