From d6e1d7e521785f276421db93eb9359b7307c0658 Mon Sep 17 00:00:00 2001
From: Andrey Churbanov <Andrey.Churbanov@intel.com>
Date: Thu, 11 Aug 2016 13:04:00 +0000
Subject: [PATCH] Fixes for hierarchical barrier (possible hang if team size
 changed).

Differential Revision: http://reviews.llvm.org/D23175

llvm-svn: 278332
---
 openmp/runtime/src/kmp_runtime.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/openmp/runtime/src/kmp_runtime.c b/openmp/runtime/src/kmp_runtime.c
index 180c533..7b2ef06 100644
--- a/openmp/runtime/src/kmp_runtime.c
+++ b/openmp/runtime/src/kmp_runtime.c
@@ -4848,6 +4848,19 @@ __kmp_allocate_team( kmp_root_t *root, int new_nproc, int max_nproc,
                 }
 #if KMP_NESTED_HOT_TEAMS
             } // (__kmp_hot_teams_mode == 0)
+            else {
+                // When keeping extra threads in team, switch threads to wait on own b_go flag
+                for (f=new_nproc; f<team->t.t_nproc; ++f) {
+                    KMP_DEBUG_ASSERT(team->t.t_threads[f]);
+                    kmp_balign_t *balign = team->t.t_threads[f]->th.th_bar;
+                    for (int b=0; b<bs_last_barrier; ++b) {
+                        if (balign[b].bb.wait_flag == KMP_BARRIER_PARENT_FLAG) {
+                            balign[b].bb.wait_flag = KMP_BARRIER_SWITCH_TO_OWN_FLAG;
+                        }
+                        KMP_CHECK_UPDATE(balign[b].bb.leaf_kids, 0);
+                    }
+                }
+            }
 #endif // KMP_NESTED_HOT_TEAMS
             team->t.t_nproc =  new_nproc;
             // TODO???: team->t.t_max_active_levels = new_max_active_levels;
@@ -5331,6 +5344,7 @@ __kmp_free_thread( kmp_info_t *this_th )
         if (balign[b].bb.wait_flag == KMP_BARRIER_PARENT_FLAG)
             balign[b].bb.wait_flag = KMP_BARRIER_SWITCH_TO_OWN_FLAG;
         balign[b].bb.team = NULL;
+        balign[b].bb.leaf_kids = 0;
     }
     this_th->th.th_task_state = 0;
 
-- 
2.7.4