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, 11 insertions, 2 deletions

diff --git a/openmp/runtime/src/z_Linux_util.c b/openmp/runtime/src/z_Linux_util.c
index 890ec5cfaaf..237677b24cf 100644
--- a/openmp/runtime/src/z_Linux_util.c
+++ b/openmp/runtime/src/z_Linux_util.c
@@ -175,8 +175,11 @@ __kmp_set_system_affinity( kmp_affin_mask_t const *mask, int abort_on_error )
 {
     KMP_ASSERT2(KMP_AFFINITY_CAPABLE(),
       "Illegal set affinity operation when not capable");
-
+#if KMP_USE_HWLOC
+    int retval = hwloc_set_cpubind(__kmp_hwloc_topology, (hwloc_cpuset_t)mask, HWLOC_CPUBIND_THREAD);
+#else
     int retval = syscall( __NR_sched_setaffinity, 0, __kmp_affin_mask_size, mask );
+#endif
     if (retval >= 0) {
         return 0;
     }
@@ -198,7 +201,11 @@ __kmp_get_system_affinity( kmp_affin_mask_t *mask, int abort_on_error )
     KMP_ASSERT2(KMP_AFFINITY_CAPABLE(),
       "Illegal get affinity operation when not capable");
 
+#if KMP_USE_HWLOC
+    int retval = hwloc_get_cpubind(__kmp_hwloc_topology, (hwloc_cpuset_t)mask, HWLOC_CPUBIND_THREAD);
+#else
     int retval = syscall( __NR_sched_getaffinity, 0, __kmp_affin_mask_size, mask );
+#endif
     if (retval >= 0) {
         return 0;
     }
@@ -220,10 +227,12 @@ __kmp_affinity_bind_thread( int which )
     KMP_ASSERT2(KMP_AFFINITY_CAPABLE(),
       "Illegal set affinity operation when not capable");
 
-    kmp_affin_mask_t *mask = (kmp_affin_mask_t *)KMP_ALLOCA(__kmp_affin_mask_size);
+    kmp_affin_mask_t *mask;
+    KMP_CPU_ALLOC_ON_STACK(mask);
     KMP_CPU_ZERO(mask);
     KMP_CPU_SET(which, mask);
     __kmp_set_system_affinity(mask, TRUE);
+    KMP_CPU_FREE_FROM_STACK(mask);
 }
 
 /*