lammps/lib/kokkos

Kokkos library

Carter Edwards, Christian Trott, others ??? (CT NOTE)
Sandia National Labs

CT NOTE: Version ???
27 May 2014

CT NOTE: Pointer to Kokkos web page???

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This directory has source files from the Kokkos library that LAMMPS
uses when building with its KOKKOS package.  The package contains
versions of pair, fix, and atom styles written with Kokkos data
structures and calls to the Kokkos library that should run efficiently
on various kinds of accelerated nodes, including GPU and many-core
chips.

Kokkos is a C++ library that provides two key abstractions for an
application like LAMMPS.  First, it allows a single implementation of
an application kernel (e.g. a pair style) to run efficiently on
different kinds of hardware (GPU, Intel Phi, many-core chip).

Second, it adjusts the memory layout of basic data structures like 2d
and 3d arrays specifically for the chosen hardware.  These are used in
LAMMPS to store atom coordinates or forces or neighbor lists.  The
layout is chosen to optimize performance on different platforms.
Again this operation is hidden from the developer, and does not affect
how the single implementation of the kernel is coded.

CT NOTE: More details???  

To build LAMMPS with Kokkos, you should not need to make any changes
to files in this directory.  You can overrided defaults that are set
in Makefile.lammps when building LAMMPS, by defining variables as part
of the make command.  Details of the build process with Kokkos are
explained in Section 2.3 of doc/Section_start.html. and in Section 5.9
of doc/Section_accelerate.html.

The one exception is that when using Kokkos with NVIDIA GPUs, the
CUDA_PATH setting in Makefile.lammps needs to point to the
installation of the Cuda software on your machine.  The normal default
location is /usr/local/cuda.  If this is not correct, you need to edit
Makefile.lammps.