diff -r fce1fa1bdc91 -r df6f2350edfa src/hotspot/share/gc/g1/g1Allocator.hpp
--- a/src/hotspot/share/gc/g1/g1Allocator.hpp	Wed Nov 13 10:49:12 2019 -0800
+++ b/src/hotspot/share/gc/g1/g1Allocator.hpp	Wed Nov 13 10:49:32 2019 -0800
@@ -54,7 +54,7 @@
 
   // Alloc region used to satisfy allocation requests by the GC for
   // survivor objects.
-  SurvivorGCAllocRegion _survivor_gc_alloc_region;
+  SurvivorGCAllocRegion* _survivor_gc_alloc_regions;
 
   // Alloc region used to satisfy allocation requests by the GC for
   // old objects.
@@ -74,13 +74,14 @@
 
   // Accessors to the allocation regions.
   inline MutatorAllocRegion* mutator_alloc_region(uint node_index);
-  inline SurvivorGCAllocRegion* survivor_gc_alloc_region();
+  inline SurvivorGCAllocRegion* survivor_gc_alloc_region(uint node_index);
   inline OldGCAllocRegion* old_gc_alloc_region();
 
   // Allocation attempt during GC for a survivor object / PLAB.
   HeapWord* survivor_attempt_allocation(size_t min_word_size,
                                         size_t desired_word_size,
-                                        size_t* actual_word_size);
+                                        size_t* actual_word_size,
+                                        uint node_index);
 
   // Allocation attempt during GC for an old object / PLAB.
   HeapWord* old_attempt_allocation(size_t min_word_size,
@@ -94,6 +95,8 @@
   G1Allocator(G1CollectedHeap* heap);
   ~G1Allocator();
 
+  uint num_nodes() { return (uint)_num_alloc_regions; }
+
 #ifdef ASSERT
   // Do we currently have an active mutator region to allocate into?
   bool has_mutator_alloc_region();
@@ -123,12 +126,14 @@
   // heap, and then allocate a block of the given size. The block
   // may not be a humongous - it must fit into a single heap region.
   HeapWord* par_allocate_during_gc(G1HeapRegionAttr dest,
-                                   size_t word_size);
+                                   size_t word_size,
+                                   uint node_index);
 
   HeapWord* par_allocate_during_gc(G1HeapRegionAttr dest,
                                    size_t min_word_size,
                                    size_t desired_word_size,
-                                   size_t* actual_word_size);
+                                   size_t* actual_word_size,
+                                   uint node_index);
 };
 
 // Manages the PLABs used during garbage collection. Interface for allocation from PLABs.
@@ -137,12 +142,12 @@
 class G1PLABAllocator : public CHeapObj<mtGC> {
   friend class G1ParScanThreadState;
 private:
+  typedef G1HeapRegionAttr::region_type_t region_type_t;
+
   G1CollectedHeap* _g1h;
   G1Allocator* _allocator;
 
-  PLAB  _surviving_alloc_buffer;
-  PLAB  _tenured_alloc_buffer;
-  PLAB* _alloc_buffers[G1HeapRegionAttr::Num];
+  PLAB** _alloc_buffers[G1HeapRegionAttr::Num];
 
   // The survivor alignment in effect in bytes.
   // == 0 : don't align survivors
@@ -155,7 +160,13 @@
   size_t _direct_allocated[G1HeapRegionAttr::Num];
 
   void flush_and_retire_stats();
-  inline PLAB* alloc_buffer(G1HeapRegionAttr dest);
+  inline PLAB* alloc_buffer(G1HeapRegionAttr dest, uint node_index) const;
+  inline PLAB* alloc_buffer(region_type_t dest, uint node_index) const;
+
+  // Returns the number of allocation buffers for the given dest.
+  // There is only 1 buffer for Old while Young may have multiple buffers depending on
+  // active NUMA nodes.
+  inline uint alloc_buffers_length(region_type_t dest) const;
 
   // Calculate the survivor space object alignment in bytes. Returns that or 0 if
   // there are no restrictions on survivor alignment.
@@ -164,6 +175,7 @@
   bool may_throw_away_buffer(size_t const allocation_word_sz, size_t const buffer_size) const;
 public:
   G1PLABAllocator(G1Allocator* allocator);
+  ~G1PLABAllocator();
 
   size_t waste() const;
   size_t undo_waste() const;
@@ -174,18 +186,21 @@
   // PLAB failed or not.
   HeapWord* allocate_direct_or_new_plab(G1HeapRegionAttr dest,
                                         size_t word_sz,
-                                        bool* plab_refill_failed);
+                                        bool* plab_refill_failed,
+                                        uint node_index);
 
   // Allocate word_sz words in the PLAB of dest.  Returns the address of the
   // allocated memory, NULL if not successful.
   inline HeapWord* plab_allocate(G1HeapRegionAttr dest,
-                                 size_t word_sz);
+                                 size_t word_sz,
+                                 uint node_index);
 
   inline HeapWord* allocate(G1HeapRegionAttr dest,
                             size_t word_sz,
-                            bool* refill_failed);
+                            bool* refill_failed,
+                            uint node_index);
 
-  void undo_allocation(G1HeapRegionAttr dest, HeapWord* obj, size_t word_sz);
+  void undo_allocation(G1HeapRegionAttr dest, HeapWord* obj, size_t word_sz, uint node_index);
 };
 
 // G1ArchiveRegionMap is a boolean array used to mark G1 regions as