src/hotspot/share/memory/padded.hpp

rev 50098 : [mq]: 8202842-g1-footprint-regressions

@@ -102,10 +102,12 @@
 template <class T, MEMFLAGS flags, size_t alignment = DEFAULT_CACHE_LINE_SIZE>
 class Padded2DArray {
  public:
   // Creates an aligned padded 2D array.
   // The memory cannot be deleted since the raw memory chunk is not returned.
+  // Always uses mmap to reserve memory. Only the first few pages with the index to
+  // the rows are touched. Allocation size should be "large" to cover page overhead.
   static T** create_unfreeable(uint rows, uint columns, size_t* allocation_size = NULL);
 };
 
 // Helper class to create an array of T objects. The array as a whole will
 // start at a multiple of alignment and its size will be aligned to alignment.