Folks -- It's worth pointing out https://github.com/open-mpi/ompi/pull/8132.
This PR will change Open MPI's behavior from building all components as DSOs to including them in the core Open MPI libraries. The motivation for this change is to decrease filesystem activity upon job start. Dlopen is still enabled by default, so if there are 3rd party components in the filesystem, Open MPI will still find / open / use them. For example: by default, the TCP BTL will no longer be built as mca_btl_tcp.so -- it will be part of libopal. That being said, you can use --enable-mca-dso to override this behavior for some/all of Open MPI's components. This can be quite useful in a developer scenario; for example, if you're writing/debugging exclusively in a component, you might want to: ./configure --enable-mca-dso=btl-tcp ... So that the TCP BTL is still built as a standalone component for ease of iterating over compiling/installing just that component. See the README changes on this PR to more fully explain --enable-mca-dso and --enable-mca-static. The behavior of --enable|disable-dlopen was also clarified. If no one objects to this change, I'll merge it next Tuesday after the weekly Open MPI webex. -- Jeff Squyres jsquy...@cisco.com