--- old/src/hotspot/share/prims/whitebox.cpp	2019-09-21 06:25:27.193961522 -0700
+++ new/src/hotspot/share/prims/whitebox.cpp	2019-09-21 06:25:26.829961534 -0700
@@ -619,6 +619,29 @@
   THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(), "WB_G1AuxiliaryMemoryUsage: G1 GC is not enabled");
 WB_END
 
+WB_ENTRY(jint, WB_G1ActiveMemoryNodeCount(JNIEnv* env, jobject o))
+  if (UseG1GC) {
+    G1MemoryNodeManager* mgr = G1MemoryNodeManager::mgr();
+    return (jint)mgr->num_active_nodes();
+  }
+  THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(), "WB_G1ActiveMemoryNodeCount: G1 GC is not enabled");
+WB_END
+
+WB_ENTRY(jintArray, WB_G1MemoryNodeIds(JNIEnv* env, jobject o))
+  if (UseG1GC) {
+    G1MemoryNodeManager* mgr = G1MemoryNodeManager::mgr();
+    int num_node_ids = (int)mgr->num_active_nodes();
+    const int* node_ids = mgr->node_ids();
+
+    typeArrayOop result = oopFactory::new_intArray(num_node_ids, CHECK_NULL);
+    for (int i = 0; i < num_node_ids; i++) {
+      result->int_at_put(i, (jint)node_ids[i]);
+    }
+    return (jintArray) JNIHandles::make_local(env, result);
+  }
+  THROW_MSG_NULL(vmSymbols::java_lang_UnsupportedOperationException(), "WB_G1MemoryNodeIds: G1 GC is not enabled");
+WB_END
+
 class OldRegionsLivenessClosure: public HeapRegionClosure {
 
  private:
@@ -2185,6 +2208,8 @@
   {CC"g1StartConcMarkCycle",       CC"()Z",           (void*)&WB_G1StartMarkCycle  },
   {CC"g1AuxiliaryMemoryUsage", CC"()Ljava/lang/management/MemoryUsage;",
                                                       (void*)&WB_G1AuxiliaryMemoryUsage  },
+  {CC"g1ActiveMemoryNodeCount", CC"()I",              (void*)&WB_G1ActiveMemoryNodeCount },
+  {CC"g1MemoryNodeIds",    CC"()[I",                  (void*)&WB_G1MemoryNodeIds },
   {CC"g1GetMixedGCInfo",   CC"(I)[J",                 (void*)&WB_G1GetMixedGCInfo },
 #endif // INCLUDE_G1GC
 #if INCLUDE_G1GC || INCLUDE_PARALLELGC