src/gromacs/utility/gmxomp.cpp

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  35 /*! \internal \file
  36  * \brief
  37  * Implements functions from gmxomp.h.
  38  *
  39  * \ingroup module_utility
  40  */
  41 #include "gmxpre.h"
  42
  43 #include "gmxomp.h"
  44
  45 #include "config.h"
  46
  47 #include <cstdio>
  48 #include <cstdlib>
  49
  50 #if GMX_OPENMP
  51 #include <omp.h>
  52 #endif
  53
  54 #include "gromacs/utility/basedefinitions.h"
  55 #include "gromacs/utility/cstringutil.h"
  56 #include "gromacs/utility/exceptions.h"
  57 #include "gromacs/utility/fatalerror.h"
  58 #include "gromacs/utility/programcontext.h"
  59 #include "gromacs/utility/stringutil.h"
  60
  61 int gmx_omp_get_max_threads()
  62 {
  63 #if GMX_OPENMP
  64     return omp_get_max_threads();
  65 #else
  66     return 1;
  67 #endif
  68 }
  69
  70 int gmx_omp_get_num_procs()
  71 {
  72 #if GMX_OPENMP
  73     return omp_get_num_procs();
  74 #else
  75     return 1;
  76 #endif
  77 }
  78
  79 int gmx_omp_get_thread_num()
  80 {
  81 #if GMX_OPENMP
  82     return omp_get_thread_num();
  83 #else
  84     return 0;
  85 #endif
  86 }
  87
  88 void gmx_omp_set_num_threads(int num_threads)
  89 {
  90 #if GMX_OPENMP
  91     omp_set_num_threads(num_threads);
  92 #else
  93     GMX_UNUSED_VALUE(num_threads);
  94 #endif
  95 }
  96
  97 gmx_bool gmx_omp_check_thread_affinity(char **message)
  98 {
  99     bool shouldSetAffinity = true;
 100
 101     *message = nullptr;
 102 #if GMX_OPENMP
 103     /* We assume that the affinity setting is available on all platforms
 104      * gcc supports. Even if this is not the case (e.g. Mac OS) the user
 105      * will only get a warning. */
 106 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
 107     const char *programName;
 108     try
 109     {
 110         programName = gmx::getProgramContext().displayName();
 111     }
 112     GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR;
 113
 114     const char *const gomp_env            = getenv("GOMP_CPU_AFFINITY");
 115     const bool        bGompCpuAffinitySet = (gomp_env != nullptr);
 116
 117     /* turn off internal pinning if GOMP_CPU_AFFINITY is set & non-empty */
 118     if (bGompCpuAffinitySet && *gomp_env != '\0')
 119     {
 120         try
 121         {
 122             std::string buf = gmx::formatString(
 123                         "NOTE: GOMP_CPU_AFFINITY set, will turn off %s internal affinity\n"
 124                         "      setting as the two can conflict and cause performance degradation.\n"
 125                         "      To keep using the %s internal affinity setting, unset the\n"
 126                         "      GOMP_CPU_AFFINITY environment variable.",
 127                         programName, programName);
 128             *message = gmx_strdup(buf.c_str());
 129         }
 130         GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR;
 131         shouldSetAffinity = false;
 132     }
 133 #endif /* __GNUC__ || __INTEL_COMPILER */
 134
 135 #if defined(__INTEL_COMPILER)
 136     const char *const kmp_env         = getenv("KMP_AFFINITY");
 137     const bool        bKmpAffinitySet = (kmp_env != NULL);
 138
 139     // turn off internal pinning if KMP_AFFINITY is set but does not contain
 140     // the settings 'disabled' or 'none'.
 141     if (bKmpAffinitySet &&
 142         (strstr(kmp_env, "disabled") == NULL) &&
 143         (strstr(kmp_env, "none") == NULL))
 144     {
 145         try
 146         {
 147             std::string buf = gmx::formatString(
 148                         "NOTE: KMP_AFFINITY set, will turn off %s internal affinity\n"
 149                         "      setting as the two can conflict and cause performance degradation.\n"
 150                         "      To keep using the %s internal affinity setting, unset the\n"
 151                         "      KMP_AFFINITY environment variable or set it to 'none' or 'disabled'.",
 152                         programName, programName);
 153             *message = gmx_strdup(buf.c_str());
 154         }
 155         GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR;
 156         shouldSetAffinity = false;
 157     }
 158 #endif /* __INTEL_COMPILER */
 159
 160 #endif /* GMX_OPENMP */
 161     return shouldSetAffinity;
 162 }