src/share/vm/memory/collectorPolicy.cpp

@@ -444,22 +444,24 @@
     _min_gen0_size = max_new_size;
     _initial_gen0_size = max_new_size;
     _max_gen0_size = max_new_size;
   } else {
     size_t desired_new_size = 0;
-    if (!FLAG_IS_DEFAULT(NewSize)) {
-      // If NewSize is set ergonomically (for example by cms), it
-      // would make sense to use it.  If it is used, also use it
-      // to set the initial size.  Although there is no reason
-      // the minimum size and the initial size have to be the same,
-      // the current implementation gets into trouble during the calculation
-      // of the tenured generation sizes if they are different.
-      // Note that this makes the initial size and the minimum size
-      // generally small compared to the NewRatio calculation.
+    if (FLAG_IS_CMDLINE(NewSize)) {
+      // If NewSize is set on the command line, we must use it as
+      // the initial size and it also makes sense to use it as the
+      // lower limit.
       _min_gen0_size = NewSize;
       desired_new_size = NewSize;
       max_new_size = MAX2(max_new_size, NewSize);
+    } else if (FLAG_IS_ERGO(NewSize)) {
+      // If NewSize is set ergonomically, we should use it as a lower
+      // limit, but use NewRatio to calculate the initial size.
+      _min_gen0_size = NewSize;
+      desired_new_size =
+        MAX2(scale_by_NewRatio_aligned(_initial_heap_byte_size), NewSize);
+      max_new_size = MAX2(max_new_size, NewSize);
     } else {
       // For the case where NewSize is the default, use NewRatio
       // to size the minimum and initial generation sizes.
       // Use the default NewSize as the floor for these values.  If
       // NewRatio is overly large, the resulting sizes can be too small.