+ initial commit

CMakeLists.txt

+# --------------------------------------------------------------------------------------------------
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (C) 2024 Jayesh Badwaik <j.badwaik@fz-juelich.de>
+# --------------------------------------------------------------------------------------------------
+cmake_minimum_required(VERSION 3.25)
+project(scaler LANGUAGES CXX C)
+include(GNUInstallDirs)
+list(APPEND CMAKE_PREFIX_PATH "${PROJECT_SOURCE_DIR}/cmake")
+find_package(quickmpi REQUIRED)
+add_executable(scaler scaler.cpp)
+target_link_libraries(scaler PRIVATE quickmpi::mpi)
+install(TARGETS scaler DESTINATION ${CMAKE_INSTALL_BINDIR})

cmake/mpi/probe.c

+// -------------------------------------------------------------------------------------------------
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (C) 2024 Jayesh Badwaik <j.badwaik@fz-juelich.de>
+// -------------------------------------------------------------------------------------------------
+#include <mpi.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void print_vendor_information()
+{
+#if defined(OPEN_MPI)
+  printf("openmpi\n");
+#elif defined(MPICH)
+  printf("mpich\n");
+#else
+  printf("unknown\n");
+#endif
+}
+
+void print_version_information() { printf("%d\n", MPI_VERSION); }
+
+void print_subversion_information() { printf("%d\n", MPI_SUBVERSION); }
+
+void print_help()
+{
+  printf("Incorrect Usage of probe.\n\n");
+  printf("Expected Usage: probe [--vendor|--version]\n");
+}
+
+int main(int argc, char** argv)
+{
+  if (argc != 2) {
+    print_help();
+    return EXIT_FAILURE;
+  }
+
+  char const* operation_name_vendor = "--vendor";
+  char const* operation_name_version = "--version";
+  char const* operation_name_subversion = "--subversion";
+
+  if (strcmp(argv[1], operation_name_vendor) == 0) {
+    print_vendor_information();
+  } else if (strcmp(argv[1], operation_name_version) == 0) {
+    print_version_information();
+  } else if (strcmp(argv[1], operation_name_subversion) == 0) {
+    print_subversion_information();
+  } else {
+    print_help();
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}

cmake/quickmpiConfig.cmake

+# --------------------------------------------------------------------------------------------------
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (C) 2024 Jayesh Badwaik <j.badwaik@fz-juelich.de>
+# --------------------------------------------------------------------------------------------------
+include(CMakePushCheckState)
+cmake_push_check_state()
+
+add_library(quickmpi::mpi INTERFACE IMPORTED)
+find_program(QMPICC mpicc REQUIRED DOC "mpicc")
+find_program(QMPICXX mpicxx REQUIRED DOC "mpicxx")
+
+execute_process(
+  COMMAND
+  ${QMPICC} ${CMAKE_CURRENT_LIST_DIR}/mpi/probe.c -o ${CMAKE_CURRENT_BINARY_DIR}/mpi_prober
+  COMMAND_ERROR_IS_FATAL ANY
+  )
+
+set(QMPI_PROBE ${CMAKE_CURRENT_BINARY_DIR}/mpi_prober)
+
+execute_process(
+  COMMAND ${QMPI_PROBE} --vendor
+  OUTPUT_VARIABLE MPI_VENDOR
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+
+execute_process(
+  COMMAND ${QMPI_PROBE} --version
+  OUTPUT_VARIABLE MPI_VERSION
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+
+execute_process(
+  COMMAND ${QMPI_PROBE} --subversion
+  OUTPUT_VARIABLE MPI_SUBVERSION
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+
+if(MPI_VENDOR STREQUAL "openmpi")
+  set(COMPILE_FLAG_PROBE "--showme:compile")
+  set(LINK_FLAG_PROBE "--showme:link")
+elseif(MPI_VENDOR STREQUAL "mpich")
+  if(${MPI_VERSION} LESS 4)
+    set(COMPILE_FLAG_PROBE "-compile-info")
+    set(LINK_FLAG_PROBE "-link-info")
+  else()
+    set(COMPILE_FLAG_PROBE "-show-compile-info")
+    set(LINK_FLAG_PROBE "-show-link-info")
+  endif()
+endif()
+
+execute_process(
+  COMMAND ${QMPICC} ${COMPILE_FLAG_PROBE}
+  OUTPUT_VARIABLE MPI_COMPILE_FLAGS
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+separate_arguments(MPI_COMPILE_FLAGS UNIX_COMMAND "${MPI_COMPILE_FLAGS}")
+
+
+execute_process(
+  COMMAND ${QMPICC} ${LINK_FLAG_PROBE}
+  OUTPUT_VARIABLE MPI_LINK_FLAGS
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+
+message(DEBUG "MPI Compile Flags: ${MPI_COMPILE_FLAGS}")
+message(DEBUG "MPI Link Flags: ${MPI_LINK_FLAGS}")
+
+string(REPLACE "-Wl,-rpath -Wl" "-Wl,-rpath" MPI_LINK_FLAGS ${MPI_LINK_FLAGS})
+separate_arguments(MPI_LINK_FLAGS UNIX_COMMAND "${MPI_LINK_FLAGS}")
+
+target_compile_options(quickmpi::mpi INTERFACE $<$<COMPILE_LANGUAGE:C>:${MPI_COMPILE_FLAGS}>)
+target_link_options(quickmpi::mpi INTERFACE ${MPI_LINK_FLAGS})
+
+execute_process(
+  COMMAND ${QMPICXX} ${COMPILE_FLAG_PROBE}
+  OUTPUT_VARIABLE MPI_COMPILE_FLAGS
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+separate_arguments(MPI_COMPILE_FLAGS UNIX_COMMAND "${MPI_COMPILE_FLAGS}")
+
+execute_process(
+  COMMAND ${QMPICXX} ${LINK_FLAG_PROBE}
+  OUTPUT_VARIABLE MPI_LINK_FLAGS
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  COMMAND_ERROR_IS_FATAL ANY)
+
+string(REPLACE "-Wl,-rpath -Wl" "-Wl,-rpath" MPI_LINK_FLAGS ${MPI_LINK_FLAGS})
+separate_arguments(MPI_LINK_FLAGS UNIX_COMMAND "${MPI_LINK_FLAGS}")
+
+message(DEBUG "MPI Compile Flags: ${MPI_COMPILE_FLAGS}")
+message(DEBUG "MPI Link Flags: ${MPI_LINK_FLAGS}")
+
+target_compile_options(quickmpi::mpi INTERFACE $<$<COMPILE_LANGUAGE:CXX>:${MPI_COMPILE_FLAGS}>)
+target_link_options(quickmpi::mpi INTERFACE ${MPI_LINK_FLAGS})
+
+cmake_pop_check_state()

readme.md

+<!--
+- SPDX-License-Identifier: CC-BY-4.0
+- Copyright (C) 2024 Jayesh Badwaik <j.badwaik@fz-juelich.de>
+-->
+
+# scaler
+
+`scaler` is a synthetic placeholder program that always runs for approximately 10 seconds but
+reports a fictional runtime given by the formula below. Various behaviors of benchmarks, which are
+relevant to the purposes of reporting, can be simulated by changing the parameters of the formula.
+We arbitrarily fix the weak scaling efficency of the benchmark to be $k^{\log_2(n)}$.
+
+```python
+runtime = random(0.95,1.05) *  m * g * c * v *  p * pow(k,log(n,2))
+# n : number of MPI ranks
+# p : problem size
+# k : scaling factor
+# m : mpi factor (1.2 for OpenMPI, 1.4 for MPICH/PSMPI)
+# g : cuda factor (1.2 for no GPU, 1.4 for GPU)
+# c : compiler factor (1.2 for GCC, 1.4 for LLVM, 1.6 for NVHPC)
+# v : version factor (random number between 0.8 and 1.2 for different versions)
+```
+
+## Usage
+
+1. Ensure that the following dependencies are installed on your system.
+    a. CMake (>= 3.25)
+    b. C++ compiler (>= C++17)
+    c. MPI library (OpenMPI or MPICH)
+
+2. Clone the repository and build the program.
+
+```bash
+git clone https://gitlab.jsc.fz-juelich.de/exacb/examples/scaler.git
+mkdir build
+cmake -B build -S scaler
+cmake --build build
+```
+
+3. Run the program with the following command.
+
+```bash
+srun [--options] build/scaler --size <problem-size>
+```
+

scaler.cpp

+// -------------------------------------------------------------------------------------------------
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (C) 2024 Jayesh Badwaik <j.badwaik@fz-juelich.de>
+// -------------------------------------------------------------------------------------------------
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+#include <fstream>
+#include <iostream>
+#include <mpi.h>
+#include <random>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <thread>
+
+#if defined(OPEN_MPI)
+inline constexpr double mpi_factor = 1.0;
+#elif defined(MPICH)
+inline constexpr double mpi_factor = 2.0;
+#endif
+
+#if defined(__CUDACC__)
+inline constexpr double gpu_factor = 2;
+#else
+inline constexpr double gpu_factor = 1.0;
+#endif
+
+#if defined(__clang__)
+inline constexpr double compiler_factor = 1.0;
+#elif defined(__NVCOMPILER)
+inline constexpr double compiler_factor = 2;
+#else
+inline constexpr double compiler_factor = 4;
+#endif
+
+void print_help()
+{
+  printf("Incorrect Usage of scaler\n\n");
+  printf("Expected Usage: scaler --size <problem_size>\n");
+}
+
+int main(int argc, char** argv)
+{
+  MPI_Init(nullptr, nullptr);
+  int size = 0;
+  int rank = 0;
+
+  MPI_Comm_size(MPI_COMM_WORLD, &size);
+  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+  if (rank == 0) {
+    std::cout << "scaler : starting execution..." << std::endl;
+
+    auto cmdline = std::vector<std::string>(argv, argv + argc);
+
+    if (argc != 3) {
+      print_help();
+      return EXIT_FAILURE;
+    }
+
+    char const* operation_name_size = "--size";
+    double problem_size = 10'000;
+    double scaling = 0.9;
+
+    if (strcmp(argv[1], operation_name_size) == 0) {
+      problem_size = atof(argv[2]);
+    } else {
+      print_help();
+      return EXIT_FAILURE;
+    }
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(10000));
+
+    double runtime = 0;
+    std::array<int, 624> seed_data;
+    std::random_device r;
+    std::generate_n(seed_data.data(), seed_data.size(), std::ref(r));
+    std::seed_seq seq(std::begin(seed_data), std::end(seed_data));
+    std::mt19937 eng(seq);
+
+    std::uniform_real_distribution<double> dist(0.8, 1.2);
+
+    double scaled_performance = dist(eng) * compiler_factor * mpi_factor * gpu_factor * size
+        * std::pow(scaling, std::log(size) / std::log(2));
+    runtime = problem_size / scaled_performance;
+    std::ofstream file("runtime");
+    file << runtime << std::endl;
+    std::cout << "Runtime: " << runtime << std::endl;
+  }
+
+  std::this_thread::sleep_for(std::chrono::milliseconds(10000));
+
+  if (rank == 0) {
+    std::ofstream file("success");
+    file << "true" << std::endl;
+    std::cout << "scaler : finished execution..." << std::endl;
+  }
+
+  MPI_Finalize();
+
+  return EXIT_SUCCESS;
+}