Changes between Version 2 and Version 3 of Public/User_Guide/Offloading_hybrid_apps

Timestamp:

Sep 17, 2019, 12:53:00 PM (5 years ago)

Author:

Kevin Sala

Comment:

—

Public/User_Guide/Offloading_hybrid_apps

@@ -1 @@
-= Offloading computational tasks of hybrid MPI+OpenMP/OmpSs-2 applications to GPUs =
+= Offloading computational tasks of hybrid MPI + OpenMP/OmpSs-2 applications to GPUs =
+
+Table of contents:
+* [#QuickOverview Quick Overview]
+* Examples:
+  * [#NBodyBenchmark NBody Benchmark]
+
+----
+
+= Quick Overview =
+
+----
+
+= NBody Benchmark =
+
+Users can clone or download this examples from the https://pm.bsc.es/gitlab/DEEP-EST/apps/NBody 
+repository and transfer it to a DEEP working directory.
+
+
+== Description
+An NBody simulation numerically approximates the evolution of a system of
+bodies in which each body continuously interacts with every other body.  A
+familiar example is an astrophysical simulation in which each body represents a
+galaxy or an individual star, and the bodies attract each other through the
+gravitational force.
+
+N-body simulation arises in many other computational science problems as well.
+For example, protein folding is studied using N-body simulation to calculate
+electrostatic and ''Van der Waals'' forces. Turbulent fluid flow simulation and
+global illumination computation in computer graphics are other examples of
+problems that use NBody simulation.
+
+== Requirements
+The requirements of this application are shown in the following lists. The main requirements are:
+
+  * '''GNU Compiler Collection'''.
+  * '''!OmpSs-2''': !OmpSs-2 is the second generation of the '''!OmpSs''' programming model. It is a task-based
+    programming model originated from the ideas of the OpenMP and !StarSs programming models. The
+    specification and user-guide are available at https://pm.bsc.es/ompss-2-docs/spec/ and
+    https://pm.bsc.es/ompss-2-docs/user-guide/, respectively. !OmpSs-2 requires both '''Mercurium''' and
+    '''Nanos6''' tools. Mercurium is a source-to-source compiler which provides the necessary support for
+    transforming the high-level directives into a parallelized version of the application. The Nanos6
+    runtime system library provides the services to manage all the parallelism in the application
+    (e.g., task creation, synchronization, scheduling, etc). Downloads at https://github.com/bsc-pm.
+  * '''Clang + LLVM OpenMP''' (derived):
+  * '''MPI''': This application requires an MPI library supporting the multi-threading level of
+    thread support.
+
+In addition, there are some optional tools which enable the building of other application versions:
+
+  * '''CUDA''' and NVIDIA '''Unified Memory''' devices: This application has CUDA variants in which some of
+    the N-body kernels are executed on the available GPU devices.
+  * '''Task-Aware MPI (TAMPI)''': The Task-Aware MPI library provides the interoperability mechanism
+    for MPI and OpenMP/!OmpSs-2. Downloads and more information at https://github.com/bsc-pm/tampi.