src/share/vm/gc_implementation/g1/g1RegionToSpaceMapper.hpp

rev 8048 : 8058354: SPECjvm2008-Derby -2.7% performance regression on Solaris-X64 starting with 9-b29
Summary: Allow partial use of large pages for auxiliary data structures in G1.
Reviewed-by: jmasa
rev 8049 : imported patch 8058354-stefank-review
rev 8050 : imported patch 8058354-more-stefank-review
rev 8051 : imported patch 8058354-more-more-stefank-review
rev 8052 : imported patch per-comments

@@ -44,16 +44,16 @@
  private:
   G1MappingChangedListener* _listener;
  protected:
   // Backing storage.
   G1PageBasedVirtualSpace _storage;
-  size_t _commit_granularity;
+
   size_t _region_granularity;
   // Mapping management
   BitMap _commit_map;
 
-  G1RegionToSpaceMapper(ReservedSpace rs, size_t commit_granularity, size_t region_granularity, MemoryType type);
+  G1RegionToSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, MemoryType type);
 
   void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);
  public:
   MemRegion reserved() { return _storage.reserved(); }
 

@@ -68,20 +68,24 @@
 
   bool is_committed(uintptr_t idx) const {
     return _commit_map.at(idx);
   }
 
-  virtual void commit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;
-  virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;
+  virtual void commit_regions(uint start_idx, size_t num_regions = 1) = 0;
+  virtual void uncommit_regions(uint start_idx, size_t num_regions = 1) = 0;
 
   // Creates an appropriate G1RegionToSpaceMapper for the given parameters.
+  // The actual space to be used within the given reservation is given by actual_size.
+  // This is because some OSes need to round up the reservation size to guarantee
+  // alignment of page_size.
   // The byte_translation_factor defines how many bytes in a region correspond to
   // a single byte in the data structure this mapper is for.
   // Eg. in the card table, this value corresponds to the size a single card
-  // table entry corresponds to.
+  // table entry corresponds to in the heap.
   static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,
-                                              size_t os_commit_granularity,
+                                              size_t actual_size,
+                                              size_t page_size,
                                               size_t region_granularity,
                                               size_t byte_translation_factor,
                                               MemoryType type);
 };