8001425: G1: Change the default values for certain G1 specific flags

Summary: Changes to default and ergonomic flag values recommended by performance team. Changes were also reviewed by Monica Beckwith <monica.beckwith@oracle.com>.
Reviewed-by: brutisso, huntch

src/share/vm/gc_implementation/g1/g1_globals.hpp

 /*
- * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -287,24 +287,24 @@
           "The number of times we'll force an overflow during "             \
           "concurrent marking")                                             \
                                                                             \
-  experimental(uintx, G1NewSizePercent, 20,                                 \
+  experimental(uintx, G1NewSizePercent, 5,                                  \
           "Percentage (0-100) of the heap size to use as default "          \
           "minimum young gen size.")                                        \
                                                                             \
-  experimental(uintx, G1MaxNewSizePercent, 80,                              \
+  experimental(uintx, G1MaxNewSizePercent, 60,                              \
           "Percentage (0-100) of the heap size to use as default "          \
           " maximum young gen size.")                                       \
                                                                             \
-  experimental(uintx, G1MixedGCLiveThresholdPercent, 90,                    \
+  experimental(uintx, G1MixedGCLiveThresholdPercent, 65,                    \
           "Threshold for regions to be considered for inclusion in the "    \
           "collection set of mixed GCs. "                                   \
           "Regions with live bytes exceeding this will not be collected.")  \
                                                                             \
-  product(uintx, G1HeapWastePercent, 5,                                     \
+  product(uintx, G1HeapWastePercent, 10,                                    \
           "Amount of space, expressed as a percentage of the heap size, "   \
           "that G1 is willing not to collect to avoid expensive GCs.")      \
                                                                             \
-  product(uintx, G1MixedGCCountTarget, 4,                                   \
+  product(uintx, G1MixedGCCountTarget, 8,                                   \
           "The target number of mixed GCs after a marking cycle.")          \
                                                                             \
   experimental(uintx, G1OldCSetRegionThresholdPercent, 10,                  \