src/gromacs/utility/gmxomp.cpp

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