--- old/src/hotspot/share/gc/g1/g1RegionToSpaceMapper.cpp	2019-09-21 06:25:11.273962076 -0700
+++ new/src/hotspot/share/gc/g1/g1RegionToSpaceMapper.cpp	2019-09-21 06:25:10.909962089 -0700
@@ -24,6 +24,7 @@
 
 #include "precompiled.hpp"
 #include "gc/g1/g1BiasedArray.hpp"
+#include "gc/g1/g1MemoryNodeManager.hpp"
 #include "gc/g1/g1RegionToSpaceMapper.hpp"
 #include "logging/log.hpp"
 #include "memory/allocation.inline.hpp"
@@ -42,7 +43,7 @@
                                              size_t commit_factor,
                                              MemoryType type) :
   _listener(NULL),
-  _storage(rs, used_size, page_size),
+  _storage(rs, used_size, page_size, type),
   _region_granularity(region_granularity),
   _commit_map(rs.size() * commit_factor / region_granularity, mtGC) {
   guarantee(is_power_of_2(page_size), "must be");
@@ -71,11 +72,12 @@
     guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity");
   }
 
-  virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
-    size_t const start_page = (size_t)start_idx * _pages_per_region;
-    bool zero_filled = _storage.commit(start_page, num_regions * _pages_per_region);
+  virtual void commit_regions(uint start_idx, size_t num_regions, uint node_index, WorkGang* pretouch_gang) {
+    const size_t start_page = (size_t)start_idx * _pages_per_region;
+    const size_t size_in_pages = num_regions * _pages_per_region;
+    bool zero_filled = _storage.commit(start_page, size_in_pages, node_index);
     if (AlwaysPreTouch) {
-      _storage.pretouch(start_page, num_regions * _pages_per_region, pretouch_gang);
+      _storage.pretouch(start_page, size_in_pages, pretouch_gang);
     }
     _commit_map.set_range(start_idx, start_idx + num_regions);
     fire_on_commit(start_idx, num_regions, zero_filled);
@@ -91,6 +93,36 @@
 // than the commit granularity.
 // Basically, the contents of one OS page span several regions.
 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {
+  // Helper class used to get node index evenly starting from the given node index.
+  // When the G1HeapRegionSize is smaller than page size, G1RegionToSpaceMapper will
+  // commit one heap region each time if multiple pages needs to be committed. In such case,
+  // node index also should reflect it. I.e. node indices should be used evenly.
+  class G1NodeDistributor : public StackObj {
+    uint _requested_node_index;
+    uint _next_node_index;
+    uint _max_node_index;
+  public:
+    G1NodeDistributor(uint node_index) :
+        _requested_node_index(node_index), 
+        // At the constructor body, _next_node_index will start from the first node index.
+        _next_node_index(G1MemoryNodeManager::mgr()->num_active_nodes() - 1),
+        _max_node_index(G1MemoryNodeManager::mgr()->num_active_nodes()) {
+      next();
+    }
+
+    uint next_node_index() const {
+      return _next_node_index;
+    }
+
+    void next() {
+      if (_requested_node_index == G1MemoryNodeManager::AnyNodeIndex) {
+        _next_node_index = (_next_node_index + 1) % _max_node_index;
+      } else {
+        _next_node_index = _requested_node_index;
+      }
+    }
+  };
+
  private:
   class CommitRefcountArray : public G1BiasedMappedArray<uint> {
    protected:
@@ -119,7 +151,7 @@
     _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_up(rs.size(), page_size)), page_size);
   }
 
-  virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
+  virtual void commit_regions(uint start_idx, size_t num_regions, uint node_index, WorkGang* pretouch_gang) {
     size_t const NoPage = ~(size_t)0;
 
     size_t first_committed = NoPage;
@@ -127,7 +159,11 @@
 
     bool all_zero_filled = true;
 
+    G1NodeDistributor itr(node_index);
+
     for (uint i = start_idx; i < start_idx + num_regions; i++) {
+      // If there are many pages to touch, different node ids will be used.
+      uint processed_node_index = itr.next_node_index();
       assert(!_commit_map.at(i), "Trying to commit storage at region %u that is already committed", i);
       size_t idx = region_idx_to_page_idx(i);
       uint old_refcount = _refcounts.get_by_index(idx);
@@ -140,7 +176,8 @@
         } else {
           num_committed++;
         }
-        zero_filled = _storage.commit(idx, 1);
+        zero_filled = _storage.commit(idx, 1, processed_node_index);
+        itr.next();
       }
       all_zero_filled &= zero_filled;
 
@@ -254,7 +291,7 @@
   return true;
 }
 
-void G1RegionToHeteroSpaceMapper::commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
+void G1RegionToHeteroSpaceMapper::commit_regions(uint start_idx, size_t num_regions, uint node_index, WorkGang* pretouch_gang) {
   uint end_idx = (start_idx + (uint)num_regions - 1);
 
   uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
@@ -265,7 +302,7 @@
     _num_committed_nvdimm += num_nvdimm;
   }
   if (num_dram > 0) {
-    _dram_mapper->commit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram, pretouch_gang);
+    _dram_mapper->commit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, node_index, num_dram, pretouch_gang);
     _num_committed_dram += num_dram;
   }
 }