Update platform tutorials

Author: shuds13

docs/platforms/frontier.rst

@@ -64,7 +64,10 @@ Now grab an interactive session on one node::
 
 Then in the session run::
 
-    python run_libe_forces.py --comms local --nworkers 8
+    python run_libe_forces.py --comms local --nworkers 9
+
+This places the generator on the first worker and runs simulations on the
+others (each simulation using one GPU).
 
 To see GPU usage, ssh into the node you are on in another window and run::
 

docs/platforms/perlmutter.rst

@@ -96,12 +96,36 @@ Now grab an interactive session on one node::
 Then in the session run::
 
     export LIBE_PLATFORM="perlmutter_g"
-    python run_libe_forces.py --comms local --nworkers 4
+    python run_libe_forces.py -n 5
+
+This places the generator on the first worker and runs simulations on the
+others (each simulation using one GPU).
 
 To see GPU usage, ssh into the node you are on in another window and run::
 
     watch -n 0.1 nvidia-smi
 
+Running generator on the manager
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+An alternative is to run the generator on a thread on the manager. The
+number of workers can then be set to the number of simulation workers.
+
+Change the libE_specs in `run_libe_forces.py` as follows.
+
+   .. code-block:: python
+
+    nsim_workers = ensemble.nworkers
+
+    # Persistent gen does not need resources
+    ensemble.libE_specs = LibeSpecs(
+        gen_on_manager=True,
+
+and run with::
+
+    python run_libe_forces.py -n 4
+
+
 To watch video
 ^^^^^^^^^^^^^^
 
@@ -128,10 +152,10 @@ to use ``mpi4py``, you should install and run as follows::
 
 This line will build ``mpi4py`` on top of a CUDA-aware Cray MPICH.
 
-To run using 4 workers (one manager)::
+To run using 5 workers (one manager)::
 
     export SLURM_EXACT=1
-    srun -n 5 python my_script.py
+    srun -n 6 python my_script.py
 
 More information on using Python and ``mpi4py`` on Perlmutter can be found
 in the `Python on Perlmutter`_ documentation.

docs/platforms/polaris.rst

@@ -39,17 +39,6 @@ environment (if you need ``conda install``). More details at `Python for Polaris
 See :doc:`here<../advanced_installation>` for more information on advanced options
 for installing libEnsemble, including using Spack.
 
-Ensuring use of mpiexec
------------------------
-
-Prior to libE v 0.10.0, when using the :doc:`MPIExecutor<../executor/mpi_executor>` it
-is necessary to manually tell libEnsemble to use``mpiexec`` instead of ``aprun``.
-When setting up the executor use::
-
-    from libensemble.executors.mpi_executor import MPIExecutor
-    exctr = MPIExecutor(custom_info={'mpi_runner':'mpich', 'runner_name':'mpiexec'})
-
-From version 0.10.0, this is not necessary.
 
 Job Submission
 --------------

docs/platforms/spock_crusher.rst

@@ -67,7 +67,10 @@ Now grab an interactive session on one node::
 
 Then in the session run::
 
-    python run_libe_forces.py --comms local --nworkers 4
+    python run_libe_forces.py -n 5
+
+This places the generator on the first worker and runs simulations on the
+others (each simulation using one GPU).
 
 To see GPU usage, ssh into the node you are on in another window and run::