Merge branch 'topic/default/update-bench-mpi' into 'branch/default'

Update bench_mpi for Debian 11

See merge request fluiddyn/fluidsim!383

.hgignore

@@ -78,6 +78,7 @@ site.cfg
 *.lock
 *.dirlock
 **/tmp*
+**/venv_*
 
 fluidsim_path
 scratch

bench/bench_mpi/README.md

@@ -0,0 +1,37 @@
+# Benchmark MPI with and without infiniband network
+
+It appears that the value of the environment variable `OMPI_MCA_pml` influences how mpi4py is built.
+Therefore, to use the infiniband network, mpi4py has to be rebuilt with something like:
+
+```sh
+export OMPI_MCA_pml=ucx
+pip install mpi4py --force-reinstall --no-binary mpi4py
+```
+
+At LEGI, there is a module `env/ib4openmpi` that sets this variable.
+
+The script `submit_legi.py` can use 2 virtual environments that should be built with something like this.
+
+First, get an interactive session on cores with the infiniband network:
+
+```sh
+oarsub -I -l "{net='ib' and os='bullseye'}/core=2,walltime=0:10:0"
+```
+
+Then,
+
+```sh
+rm -rf venv_mpi_ib venv_mpi_noib
+# module with infiniband
+module purge
+/usr/bin/python3 -m venv venv_mpi_ib
+. venv_mpi_ib/bin/activate
+module load env/ib4openmpi
+pip install mpi4py --no-binary mpi4py
+deactivate
+# module without infiniband
+module purge
+/usr/bin/python3 -m venv venv_mpi_noib
+. venv_mpi_noib/bin/activate
+pip install mpi4py --no-binary mpi4py
+```

bench/bench_mpi/submit_legi.py

@@ -14,23 +14,22 @@
 cluster.commands_setting_env = [
     "source /etc/profile",
     "export MPI4PY_RC_THREAD_LEVEL=serialized",
+    "module purge",
 ]
 
 if infiniband:
-    name_venv = "mpi_ib"
+    name_venv = "venv_mpi_ib"
 else:
-    name_venv = "mpi_noib"
+    name_venv = "venv_mpi_noib"
 
 name_run = "bench_py_" + name_venv
 
-cluster.commands_setting_env.append(
-    f"source /home/users/augier3pi/envs/{name_venv}/bin/activate"
-)
+cluster.commands_setting_env.append(f"source {name_venv}/bin/activate")
 
 if infiniband:
-    cluster.commands_setting_env.append("module load openmpi/4.0.5-ib")
-
-resource_conditions = "net='ib' and os='buster'"
+    cluster.commands_setting_env.append(
+        "module load env/ib4openmpi  # export OMPI_MCA_pml=ucx",
+    )
 
 nb_nodes = 2
 
@@ -44,5 +43,5 @@
     omp_num_threads=1,
     walltime="0:10:00",
     ask=False,
-    resource_conditions=resource_conditions,
+    resource_conditions="net='ib' and os='bullseye'",
 )