--- a/hotspot/src/share/vm/runtime/os.hpp	Thu Jun 26 18:55:29 2014 -0700
+++ b/hotspot/src/share/vm/runtime/os.hpp	Wed Jul 02 13:52:52 2014 +0200
@@ -253,11 +253,19 @@
   // Return the default page size.
   static int    vm_page_size();
 
-  // Returns the page size to use for a region of memory.
-  // region_size / min_pages will always be greater than or equal to the
-  // returned value.
-  static size_t page_size_for_region(size_t region_size, size_t min_pages);
-
+  // Return the page size to use for a region of memory.  The min_pages argument
+  // is a hint intended to limit fragmentation; it says the returned page size
+  // should be <= region_max_size / min_pages.  Because min_pages is a hint,
+  // this routine may return a size larger than region_max_size / min_pages.
+  //
+  // The current implementation ignores min_pages if a larger page size is an
+  // exact multiple of both region_min_size and region_max_size.  This allows
+  // larger pages to be used when doing so would not cause fragmentation; in
+  // particular, a single page can be used when region_min_size ==
+  // region_max_size == a supported page size.
+  static size_t page_size_for_region(size_t region_min_size,
+                                     size_t region_max_size,
+                                     uint min_pages);
   // Return the largest page size that can be used
   static size_t max_page_size() {
     // The _page_sizes array is sorted in descending order.