.. default-domain:: chpl

.. module:: GpuDiagnostics
   :synopsis: Supports counting and reporting GPU operations.

GpuDiagnostics
==============
**Usage**

.. code-block:: chapel

   use GpuDiagnostics;


or

.. code-block:: chapel

   import GpuDiagnostics;

Supports counting and reporting GPU operations.

.. warning::

  This module is unstable and its interface is subject to change in the
  future.

  GPU support is a relatively new feature to Chapel and is under active
  development.

  For the most up-to-date information about GPU support see the
  :ref:`technical note <readme-gpu>` about it.

.. record:: chpl_gpuDiagnostics

   
   Aggregated GPU operation counts. ``host_to_device``, ``device_to_host`` and
   ``device_to_device`` will be non-zero only when
   ``CHPL_GPU_MEM_STRATEGY==array_on_device`` and ``CHPL_GPU!=cpu``.
   

   .. attribute:: var kernel_launch: uint(64)

   .. attribute:: var host_to_device: uint(64)

   .. attribute:: var device_to_host: uint(64)

   .. attribute:: var device_to_device: uint(64)

.. type:: type gpuDiagnostics = chpl_gpuDiagnostics

   
   The Chapel record type inherits the runtime definition of it.
   

.. function:: proc startVerboseGpu()

   
   Start on-the-fly reporting of GPU operations initiated on any locale.
   

.. function:: proc stopVerboseGpu()

   
   Stop on-the-fly reporting of GPU operations initiated on any locale.
   

.. function:: proc startGpuDiagnostics()

   
   Start counting GPU operations across the whole program.
   

.. function:: proc stopGpuDiagnostics()

   
   Stop counting GPU operations across the whole program.
   

.. function:: proc resetGpuDiagnostics()

   
   Reset aggregate GPU operation counts across the whole program.
   

.. function:: proc getGpuDiagnostics()

   
   Retrieve aggregate GPU operation counts for the whole program.
   
   :returns: array of counts of GPU ops initiated on each locale
   :rtype: `[LocaleSpace] gpuDiagnostics`