This commit represents the conversion of the usnic BTL from verbs to
libfabric.
For the moment, libfabric is embedded in Open MPI (currently in the
usnic BTL). This is because the libfabric API is still changing, and
also has not yet been released. Ultimately, this embedded copy of
libfabric will likely disappear and the usnic BTL will rely on an
external installation of libfabric.
New configure options:
* --with-libfabric: will cause configure to fail if libfabric support
cannot be built
* --without-libfabric: will prevent libfabric support from being built
* --with-libfabric=DIR: use an external libfabric installation
* --with-libfabric-libdir=LIBDIR: when paired with --with-libfabric=DIR,
use LIBDIR for the libfabric installation library dir
The --with-libnl3[-libdir] arguments are now gone.
If OPAL_MODEX_RECV() returns OPAL_ERR_NOT_FOUND, the peer didn't
send any Portals4 BTL info. This is not a fatal error. Instead of
disqualifying the Portals4 BTL just ignore that peer.
@jsquyres reported this in #194.
inserted in the ompi_proc_list as soon as it is created and it
is removed only upon the call to the destructor. In ompi_proc_finalize
we loop over all procs in ompi_proc_finalize and release them once.
However, as a proc is not removed from this list right away, we
decrease the ref count for each proc until it reach zero and the
proc is finally removed. Thus, we cannot clean the BML/BTL after
the call the ompi_proc_finalize.
A quick fix is to delay the call to ompi_proc_finalize until all
other frameworks have been finalized, and then the behavior
depicted above will give the expected outcome.
value NULL for the descriptor
The send inline optimization uses the btl_sendi function to achieve
lower latency and higher message rates. The problem is the btl_sendi
function was allowed to return a descriptor to the caller. This is fine
for some paths but not ok for the send inline optimization. To fix
this the btl now must be able to handle descriptor = NULL.
structure
This structure member was originally used to specify the remote segment
for an RDMA operation. Since the new btl interface no longer uses
desriptors for RDMA this member no longer has a purpose. In addition
to removing these members the local segment information has been
renamed to des_segments/des_segment_count.
