.. _Chap:InputsVerbosity:

Advanced
========

Testing / debugging
-------------------

The following inputs must be preceded by the prefix ``mfix``:

+------------------------+-----------------------------------------------------------------------+-------------+--------------+
|                        | Description                                                           |   Type      | Default      |
+========================+=======================================================================+=============+==============+
| verbose                |  Verbosity in MFIX-Exa routines                                       |    Int      |   0          |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+
| ooo_debug              |  If true, print the name of the current routine.                      |   Bool      | false        |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+
| only_print_grid_report |  Do not time-march the simulation. Simply generate the grid report    |   Bool      | false        |
|                        |  and exit.                                                            |             |              |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+
| stop_for_unused_inputs |  Do not start the simulation if any keywords in the inputs file       |   Bool      | false        |
|                        |  have not been used. This is useful for catching input errors.        |             |              |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+

To assist in verifying the breakdown of fluid grids created before running a full simulation, an input option
``mfix.only_print_grid_report`` is supported. By default, it is ``false``. When set to ``true``, the run uses
minimal memory to print the grid coverage report and exits immediately after that.


The following inputs must be preceded by the prefix ``amrex``:

+------------------------+-----------------------------------------------------------------------+-------------+--------------+
|                        | Description                                                           |   Type      | Default      |
+========================+=======================================================================+=============+==============+
| fpe_trap_invalid       |  Abort if an invalid floating point exception is encountered.         |  Bool       | false        |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+
| fpe_trap_zero          |  Abort if a division by zero is computed.                             |  Bool       | false        |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+
| fpe_trap_overflow      |  Abort if an overflow is detected.                                    |  Bool       | false        |
+------------------------+-----------------------------------------------------------------------+-------------+--------------+

GPU memory
----------

The following inputs must be preceded by the prefix ``amrex``:

+----------------------------+-----------------------------------------------------------------------+-------------+---------------+
|                            | Description                                                           |   Type      | Default       |
+============================+=======================================================================+=============+===============+
| the_arena_is_managed       | Use managed memory for the main arena.                                |  Bool       | false         |
+----------------------------+-----------------------------------------------------------------------+-------------+---------------+
| the_arena_init_size        | Initial size of main memory arena (bytes).  If not specified, use     |  Int        | Unspecified   |
|                            | 3/4 of system device memory.                                          |             |               |
+----------------------------+-----------------------------------------------------------------------+-------------+---------------+
| abort_on_out_of_gpu_memory | Abort if free device memory is less than the amount an arena is       |  Bool       | false         |
|                            | asked to allocate.                                                    |             |               |
+----------------------------+-----------------------------------------------------------------------+-------------+---------------+
| use_gpu_aware_mpi          | For GPU runs,controls the memory type used for AMReX's communication  |  Bool       | false         |
|                            | buffers. When ``true``, AMReX uses GPU device memory for communication|             |               |
|                            | data in MPI function calls. When ``false``, the data is placed in     |             |               |
|                            | pinned memory. Note that this flag does not enable GPU-aware MPI by   |             |               |
|                            | itself. Enabling GPU-aware MPI is system dependent. Users should      |             |               |
|                            | consult their system's documentation for instructions on setting up   |             |               |
|                            | the environment and linking to GPU-aware MPI libraries.               |             |               |
+----------------------------+-----------------------------------------------------------------------+-------------+---------------+


Load balancing
--------------

Note that when running a granular simulation, i.e., no fluid phase, ``mfix.load_balance`` defaults to ``SingleGrid``. Hence,
the ``particles.max_grid_size`` (in each direction) have no meaning. Therefore the fluid grid and tile
sizes should be set for particle load balancing. It may also be necessary to set the blocking factors to 1.


The following inputs must be preceded by the prefix ``mfix.load_balance`` and control load balancing:

+----------------------------------+-----------------------------------------------------------------------+-------------+-------------------+
|                                  | Description                                                           |   Type      | Default           |
+==================================+=======================================================================+=============+===================+
| grid_type                        | Grid type.                                                            |  String     | SingleGrid        |
|                                  |                                                                       |             |                   |
|                                  | Options:                                                              |             |                   |
|                                  |                                                                       |             |                   |
|                                  | * ``SingleGrid`` - fluid and particles are co-located on the same grid|             |                   |
|                                  | * ``DualGrid`` - fluid and particles occupy different grids           |             |                   |
+----------------------------------+-----------------------------------------------------------------------+-------------+-------------------+
| DualGrid.fluid                   | Regrid mesh (fluid) in addition to particles when using `DualGrid`    |  Int        | 0                 |
+----------------------------------+-----------------------------------------------------------------------+-------------+-------------------+
| strategy                         | Strategy to use for dynamic load balancing.                           |  String     | KnapSack          |
|                                  |                                                                       |             |                   |
|                                  | Options (case-insensitive):                                           |             |                   |
|                                  |                                                                       |             |                   |
|                                  | * ``KnapSack``                                                        |             |                   |
|                                  | * ``SFC``                                                             |             |                   |
+----------------------------------+-----------------------------------------------------------------------+-------------+-------------------+
| weighting                        | Weighting function to use if using ``KnapSack`` load balancing        |  String     | ParticleRunTime   |
|                                  |                                                                       |             |                   |
|                                  | Options:                                                              |             |                   |
|                                  |                                                                       |             |                   |
|                                  | * ``ParticleRunTime``                                                 |             |                   |
|                                  | * ``ParticleCount``                                                   |             |                   |
|                                  | * ``CellCount``                                                       |             |                   |
+----------------------------------+-----------------------------------------------------------------------+-------------+-------------------+
| knapsack.nmax                    | Maximum number of grids per MPI process if using knapsack algorithm   |  Int        | 128               |
+----------------------------------+-----------------------------------------------------------------------+-------------+-------------------+


The following inputs are defined using the prefix ``particles``:

+----------------------+-----------------------------------------------------------------------+-------------+--------------+
|                      | Description                                                           |   Type      | Default      |
+======================+=======================================================================+=============+==============+
| max_grid_size_x      | Maximum number of cells at level 0 in each grid in x-direction        |    Int      | 32           |
|                      | for grids in the ParticleBoxArray if ``load_balance`` is ``DualGrid``.|             |              |
+----------------------+-----------------------------------------------------------------------+-------------+--------------+
| max_grid_size_y      | Maximum number of cells at level 0 in each grid in y-direction        |    Int      | 32           |
|                      | for grids in the ParticleBoxArray if ``load_balance`` is ``DualGrid``.|             |              |
+----------------------+-----------------------------------------------------------------------+-------------+--------------+
| max_grid_size_z      | Maximum number of cells at level 0 in each grid in z-direction        |    Int      | 32           |
|                      | for grids in the ParticleBoxArray if ``load_balance`` is ``DualGrid``.|             |              |
+----------------------+-----------------------------------------------------------------------+-------------+--------------+

The following input is defined using the prefix ``eb2``:

+----------------------+-----------------------------------------------------------------------+-------------+--------------+
|                      | Description                                                           |   Type      | Default      |
+======================+=======================================================================+=============+==============+
| max_grid_size        | Specifies the maximum grid size in AMReX's internal EB database.      |    Int      | 64           |
+----------------------+-----------------------------------------------------------------------+-------------+--------------+