Force HWLOC topology method in case user requested NUMA-specific topology via granularity or KMP_HW_SUBSET

[AndreyChurbanov]

Summary

If e.g. user requested affinity with granularity=tile we need to either use HWLOC or ignore the request. The change allows user to not specify KMP_TOPOLOGY_MATHOD=hwloc and choose it automatically instead.

[jlpeyton]

LGTM

openmp/trunk/runtime/src/kmp_settings.cpp

 #else
     __kmp_set_user_lock_vptrs(__kmp_user_lock_kind);
 #endif
   }
 
 #if KMP_AFFINITY_SUPPORTED
 
   if (!TCR_4(__kmp_init_middle)) {
+#if KMP_USE_HWLOC
+    // Force using hwloc when either tiles or numa nodes requested within
+    // KMP_HW_SUBSET and no other topology method is requested
+    if ((__kmp_hws_node.num > 0 || __kmp_hws_tile.num > 0 ||
+         __kmp_affinity_gran == affinity_gran_tile) &&
+        (__kmp_affinity_top_method == affinity_top_method_default)) {
+      __kmp_affinity_top_method = affinity_top_method_hwloc;
+    }
+#endif
     // Determine if the machine/OS is actually capable of supporting
     // affinity.
     const char *var = "KMP_AFFINITY";
     KMPAffinity::pick_api();
 #if KMP_USE_HWLOC
     // If Hwloc topology discovery was requested but affinity was also disabled,
     // then tell user that Hwloc request is being ignored and use default
     // topology discovery method.