There is an ongoing discussion about this on issue #4067 ( https://github.com/open-mpi/ompi/issues/4067). Also the mailing list contains few examples on how to tweak the collective algorithms to your needs. George. On Thu, Jun 6, 2019 at 7:42 PM hash join via users wrote: > Hi all, > > > I
Leo, In a UMA system having the displacement and/or recvcounts arrays on managed GPU memory should work, but it will incur overheads for at least 2 reasons: 1. the MPI API arguments are checked for correctness (here recvcounts) 2. the collective algorithm part that executes on the CPU uses the
To completely disable UCX you need to disable the UCX MTL and not only the BTL. I would use "--mca pml ob1 --mca btl ^ucx —mca btl_openib_allow_ib 1". As you have a gdb session on the processes you can try to break on some of the memory allocations function (malloc, realloc, calloc). George.
Depending on the alignment of the different types there might be small holes in the low-level headers we exchange between processes It should not be a concern for users. valgrind should not stop on the first detected issue except if --exit-on-first-error has been provided (the default value
Jon, The configure AC_HEADER_STDC macro is considered obsolete  as most of the OSes are STDC compliant nowadays. To have it failing on a recent version of OSX, is therefore something unexpected. Moreover, many of the OMPI developers work on OSX Mojave with the default compiler but with the