Use --oversubscribe for parallel CI jobs

The option previously used only works for OpenMPI v4 and earlier - the
options changed in v5 because they changed the backend (? see
open-mpi/ompi#8955). `--oversubscribe` seems
more generic, so hopefully keeps working.

.github/workflows/debug_checks.yml

@@ -33,11 +33,7 @@ jobs:
           julia --project -O3 --check-bounds=yes -e 'using Pkg; Pkg.develop(path="moment_kinetics/"); Pkg.precompile()'
           julia --project -O3 --check-bounds=yes precompile.jl --debug 2
 
-          # Need to use openmpi so that the following arguments work:
-          # * `--mca rmaps_base_oversubscribe 1` allows oversubscription (more processes
-          #   than physical cores).
-          # * `--mca mpi_yield_when_idle 1` changes a setting to prevent excessively
-          #   terrible performance when oversubscribing.
+          # Need to use openmpi so that we can use `--oversubscribe` to allow using more MPI ranks than physical cores
           ## Don't use --compiled-modules=no for now, as it currently breaks Symbolics.jl
-          #mpiexec -np 4 --mca rmaps_base_oversubscribe 1 julia --project --check-bounds=yes --compiled-modules=no moment_kinetics/debug_test/sound_wave_tests.jl --debug 2
-          ./mpiexecjl -np 4 --mca rmaps_base_oversubscribe 1 julia --project -Jmoment_kinetics.so -O3 --check-bounds=yes moment_kinetics/debug_test/runtests.jl --debug 2
+          #mpiexec -np 4 --oversubscribe 1 julia --project --check-bounds=yes --compiled-modules=no moment_kinetics/debug_test/sound_wave_tests.jl --debug 2
+          ./mpiexecjl -np 4 --oversubscribe julia --project -Jmoment_kinetics.so -O3 --check-bounds=yes moment_kinetics/debug_test/runtests.jl --debug 2

.github/workflows/parallel_test.yml

@@ -25,14 +25,10 @@ jobs:
           julia --project -O3 --check-bounds=no -e 'using MPI; MPI.install_mpiexecjl(; destdir=".")'
           julia --project -O3 --check-bounds=no -e 'import Pkg; Pkg.add(["Random", "SpecialFunctions", "Test"]); Pkg.develop(path="moment_kinetics/")'
           julia --project -O3 --check-bounds=no -e 'import Pkg; Pkg.precompile()'
-          # Need to use openmpi so that the following arguments work:
-          # * `--mca rmaps_base_oversubscribe 1` allows oversubscription (more processes
-          #   than physical cores).
-          # * `--mca mpi_yield_when_idle 1` changes a setting to prevent excessively
-          #   terrible performance when oversubscribing.
-          ./mpiexecjl -np 3 --mca rmaps_base_oversubscribe 1 julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1
-          ./mpiexecjl -np 4 --mca rmaps_base_oversubscribe 1 julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1
-          ./mpiexecjl -np 2 --mca rmaps_base_oversubscribe 1 julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1 --long
+          # Need to use openmpi so that we can use `--oversubscribe` to allow using more MPI ranks than physical cores
+          ./mpiexecjl -np 3 --oversubscribe julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1
+          ./mpiexecjl -np 4 --oversubscribe julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1
+          ./mpiexecjl -np 2 --oversubscribe julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1 --long
           # Note: MPI.jl's default implementation is mpich, which has a similar option
           # `--with-device=ch3:sock`, but that needs to be set when compiling mpich.
         shell: bash
@@ -54,12 +50,8 @@ jobs:
           julia --project -O3 --check-bounds=no -e 'using MPI; MPI.install_mpiexecjl(; destdir=".")'
           julia --project -O3 --check-bounds=no -e 'import Pkg; Pkg.add(["Random", "SpecialFunctions", "Test"]); Pkg.develop(path="moment_kinetics/")'
           julia --project -O3 --check-bounds=no -e 'import Pkg; Pkg.precompile()'
-          # Need to use openmpi so that the following arguments work:
-          # * `--mca rmaps_base_oversubscribe 1` allows oversubscription (more processes
-          #   than physical cores).
-          # * `--mca mpi_yield_when_idle 1` changes a setting to prevent excessively
-          #   terrible performance when oversubscribing.
-          ./mpiexecjl -np 4 --mca rmaps_base_oversubscribe 1 julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1
+          # Need to use openmpi so that we can use `--oversubscribe` to allow using more MPI ranks than physical cores
+          ./mpiexecjl -np 4 --oversubscribe julia --project -O3 --check-bounds=no moment_kinetics/test/runtests.jl --debug 1
           # Note: MPI.jl's default implementation is mpich, which has a similar option
           # `--with-device=ch3:sock`, but that needs to be set when compiling mpich.
         shell: bash