Adding Hwloc library option for affinity mechanism

These changes allow libhwloc to be used as the topology discovery/affinity
mechanism for libomp.  It is supported on Unices. The code additions:
* Canonicalize KMP_CPU_* interface macros so bitmask operations are
  implementation independent and work with both hwloc bitmaps and libomp
  bitmaps.  So there are new KMP_CPU_ALLOC_* and KMP_CPU_ITERATE() macros and
  the like. These are all in kmp.h and appropriately placed.
* Hwloc topology discovery code in kmp_affinity.cpp. This uses the hwloc
  interface to create a libomp address2os object which the rest of libomp knows
  how to handle already.
* To build, use -DLIBOMP_USE_HWLOC=on and
  -DLIBOMP_HWLOC_INSTALL_DIR=/path/to/install/dir [default /usr/local]. If CMake
  can't find the library or hwloc.h, then it will tell you and exit.

Differential Revision: http://reviews.llvm.org/D13991

llvm-svn: 254320

1 files changed, 37 insertions, 0 deletions

diff --git a/openmp/runtime/src/kmp_settings.c b/openmp/runtime/src/kmp_settings.c
index 51b23ee2e46..d9485b05af0 100644
--- a/openmp/runtime/src/kmp_settings.c
+++ b/openmp/runtime/src/kmp_settings.c
@@ -3009,6 +3009,11 @@ __kmp_stg_parse_topology_method( char const * name, char const * value,
     else if ( __kmp_str_match( "flat", 1, value ) ) {
         __kmp_affinity_top_method = affinity_top_method_flat;
     }
+# if KMP_USE_HWLOC
+    else if ( __kmp_str_match( "hwloc", 1, value) ) {
+        __kmp_affinity_top_method = affinity_top_method_hwloc;
+    }
+# endif
     else {
         KMP_WARNING( StgInvalidValue, name, value );
     }
@@ -5119,11 +5124,43 @@ __kmp_env_initialize( char const * string ) {
         // affinity.
         //
         const char *var = "KMP_AFFINITY";
+# if KMP_USE_HWLOC
+        if(hwloc_topology_init(&__kmp_hwloc_topology) < 0) {
+            __kmp_hwloc_error = TRUE;
+            if(__kmp_affinity_verbose)
+                KMP_WARNING(AffHwlocErrorOccurred, var, "hwloc_topology_init()");
+        }
+        hwloc_topology_ignore_type(__kmp_hwloc_topology, HWLOC_OBJ_CACHE);
+# endif
         if ( __kmp_affinity_type == affinity_disabled ) {
             KMP_AFFINITY_DISABLE();
         }
         else if ( ! KMP_AFFINITY_CAPABLE() ) {
+# if KMP_USE_HWLOC
+            const hwloc_topology_support* topology_support = hwloc_topology_get_support(__kmp_hwloc_topology);
+            if(hwloc_topology_load(__kmp_hwloc_topology) < 0) {
+                __kmp_hwloc_error = TRUE;
+                if(__kmp_affinity_verbose)
+                    KMP_WARNING(AffHwlocErrorOccurred, var, "hwloc_topology_load()");
+            }
+            // Is the system capable of setting/getting this thread's affinity?
+            // also, is topology discovery possible? (pu indicates ability to discover processing units)
+            // and finally, were there no errors when calling any hwloc_* API functions?
+            if(topology_support->cpubind->set_thisthread_cpubind &&
+               topology_support->cpubind->get_thisthread_cpubind &&
+               topology_support->discovery->pu &&
+               !__kmp_hwloc_error)
+            {
+                // enables affinity according to KMP_AFFINITY_CAPABLE() macro
+                KMP_AFFINITY_ENABLE(TRUE);
+            } else {
+                // indicate that hwloc didn't work and disable affinity
+                __kmp_hwloc_error = TRUE;
+                KMP_AFFINITY_DISABLE();
+            }
+# else
             __kmp_affinity_determine_capable( var );
+# endif // KMP_USE_HWLOC
             if ( ! KMP_AFFINITY_CAPABLE() ) {
                 if ( __kmp_affinity_verbose || ( __kmp_affinity_warnings
                   && ( __kmp_affinity_type != affinity_default )