6.0.x FeatureList (OBSOLETE)

No timeline estimated yet. Probably not until summer 2020 at the earliest.

• Link to the 5.0 features page
• Link to the 4.0 features page

Deferred to v6.0.x from v5.0.x

• Remove TKR version of use mpi module.

  • This was deferred from 4.0.x because in April/May 2018 (and then deferred again from v5.0.x in October 2018), it was discovered that:
    1. The RHEL 7.x default gcc (4.8.5) still uses the TKR mpi module
    2. The NAG compiler still uses the TKR mpi module.
  • Is it time to re-evaluate? (RHEL 7 is going to be around for a while -- it may take a while before we can delete the the TKR mpi module, but keeping this item here for completeness)
  • 😢

• Remove all deleted MPI-1 and MPI-2 functionality

  • We removed the C++ bindings in OMPI v5.0 (this bullet being written in Oct 2018, long before v5.0.0 was even forked, so make sure that that actually happened).
  • Is it time to remove MPI_ATTR_DELETE, etc.?
    • These were all been marked as "deprecated" (possibly in 2.0.x series? definitely by the 3.0.x series).
    • In the v4.0.x series, the C++ bindings are not built by default
    • In the v4.0.x series, mpi.h/mpif.h/mpi+mpi_f08 modules do not have prototypes/declarations for all the MPI-1 deleted functions and globals (although they still contained the symbols in the libraries for ABI compatibility reasons). --enable-mpi-compatibility could be used to re-add these symbols to mpi.h, but emitted deprecated warnings if you used them.
    • We talked about removing the symbols in v5.0.x -- and almost did it -- but then decided that not enough of the MPI community was going to update from these MPI-1 and MPI-2 functions by v5.0.x (estimate summer 2018).
  • We need to re-evaluate for v6.0.0 whether it's ok to remove all these MPI-1/MPI-2 deleted symbols for good (i.e., is the MPI community ready for this).
  • THIS WILL CHANGE ABI, and therefore the major .so version of libmpi will change. THIS AFFECTS OUR PACKAGERS. We talked about this with our packagers in the v4.0.x timeframe, but we should remind them of this change (see https://github.com/open-mpi/ompi/issues/5447 and https://www.mail-archive.com/[email protected]/msg00015.html for a bit more history on what happened in the v4.0.x timeframe).