Quicksilver
Introduction
Quicksilver is a proxy application that represents some elements of the Mercury workload by solving a simplified dynamic monte carlo particle transport problem. Quicksilver attempts to replicate the memory access patterns, communication patterns, and the branching or divergence of Mercury for problems using multigroup cross sections. OpenMP and MPI are used for parallelization. A GPU version is available. Unified memory is assumed.
Performance of Quicksilver is likely to be dominated by latency bound table look-ups, a highly branchy/divergent code path, and poor vectorization potential.
For more information, visit the LLNL co-design pages.
Building Quicksilver
Instructions to build Quicksilver can be found in the Makefile. Quicksilver is a relatively easy to build code with no external dependencies (except MPI and OpenMP). You should be able to build Quicksilver on nearly any system by customizing the values of only four variables in the Makefile:
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CXX The name of the C++ compiler (with path if necessary) Quicksilver uses C++11 features, so a C++11 compliant compiler should be used.
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CXXFLAGS Command line switches to pass to the C++ compiler when compiling objects and when linking the executable.
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CPPFLAGS Command line switches to pass to the compiler only when compiling objects
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LDFLAGS Command line switches to pass to the compiler only when linking the executable
Sample definitions for a number of common systems are provided.
Quicksilver recognizes a number of pre-processor macros that enable or disable various code features such as MPI, OpenMP, etc. These are described in the Makefile.
Running Quicksilver
Quicksilver’s behavior is controlled by a combination of command line
options and an input file. All of the parameters that can be set on
the command line can also be set in the input file. The input file
values will override the command line. Run $ qs –h to see
documentation on the available command line switches. Documentation
of the input file parameters is in preparation.
Quicksilver also has the property that the output of every run is a valid input file. Hence you can repeat any run for which you have the output file by using that output as an input file.
License and Distribution Information
Quicksilver is available on github
Quicksilver is open source software with a BSD license. See LICENSE.md
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
LLNL-CODE-684037