8001424: G1: Rename certain G1-specific flags

Summary: Rename G1DefaultMinNewGenPercent, G1DefaultMaxNewGenPercent, and G1OldCSetRegionLiveThresholdPercent to G1NewSizePercent, G1MaxNewSizePercent, and G1MixedGCLiveThresholdPercent respectively. The previous names are no longer accepted.
Reviewed-by: brutisso, ysr

src/share/vm/gc_implementation/g1/collectionSetChooser.cpp

@@ -85,7 +85,7 @@ CollectionSetChooser::CollectionSetChooser() :
     _curr_index(0), _length(0), _first_par_unreserved_idx(0),
     _region_live_threshold_bytes(0), _remaining_reclaimable_bytes(0) {
   _region_live_threshold_bytes =
-    HeapRegion::GrainBytes * (size_t) G1OldCSetRegionLiveThresholdPercent / 100;
+    HeapRegion::GrainBytes * (size_t) G1MixedGCLiveThresholdPercent / 100;
 }
 
 #ifndef PRODUCT

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp

@@ -309,9 +309,9 @@ void G1CollectorPolicy::initialize_flags() {
 }
 
 G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults), _adaptive_size(true) {
-  assert(G1DefaultMinNewGenPercent <= G1DefaultMaxNewGenPercent, "Min larger than max");
-  assert(G1DefaultMinNewGenPercent > 0 && G1DefaultMinNewGenPercent < 100, "Min out of bounds");
-  assert(G1DefaultMaxNewGenPercent > 0 && G1DefaultMaxNewGenPercent < 100, "Max out of bounds");
+  assert(G1NewSizePercent <= G1MaxNewSizePercent, "Min larger than max");
+  assert(G1NewSizePercent > 0 && G1NewSizePercent < 100, "Min out of bounds");
+  assert(G1MaxNewSizePercent > 0 && G1MaxNewSizePercent < 100, "Max out of bounds");
 
   if (FLAG_IS_CMDLINE(NewRatio)) {
     if (FLAG_IS_CMDLINE(NewSize) || FLAG_IS_CMDLINE(MaxNewSize)) {
@@ -344,12 +344,12 @@ G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults), _adaptive_size(
 }
 
 uint G1YoungGenSizer::calculate_default_min_length(uint new_number_of_heap_regions) {
-  uint default_value = (new_number_of_heap_regions * G1DefaultMinNewGenPercent) / 100;
+  uint default_value = (new_number_of_heap_regions * G1NewSizePercent) / 100;
   return MAX2(1U, default_value);
 }
 
 uint G1YoungGenSizer::calculate_default_max_length(uint new_number_of_heap_regions) {
-  uint default_value = (new_number_of_heap_regions * G1DefaultMaxNewGenPercent) / 100;
+  uint default_value = (new_number_of_heap_regions * G1MaxNewSizePercent) / 100;
   return MAX2(1U, default_value);
 }
 

src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp

@@ -94,18 +94,18 @@ class TraceGen1TimeData : public CHeapObj<mtGC> {
 // will occur.
 //
 // If nothing related to the the young gen size is set on the command
-// line we should allow the young gen to be between
-// G1DefaultMinNewGenPercent and G1DefaultMaxNewGenPercent of the
-// heap size. This means that every time the heap size changes the
-// limits for the young gen size will be updated.
+// line we should allow the young gen to be between G1NewSizePercent
+// and G1MaxNewSizePercent of the heap size. This means that every time
+// the heap size changes, the limits for the young gen size will be
+// recalculated.
 //
 // If only -XX:NewSize is set we should use the specified value as the
-// minimum size for young gen. Still using G1DefaultMaxNewGenPercent
-// of the heap as maximum.
+// minimum size for young gen. Still using G1MaxNewSizePercent of the
+// heap as maximum.
 //
 // If only -XX:MaxNewSize is set we should use the specified value as the
-// maximum size for young gen. Still using G1DefaultMinNewGenPercent
-// of the heap as minimum.
+// maximum size for young gen. Still using G1NewSizePercent of the heap
+// as minimum.
 //
 // If -XX:NewSize and -XX:MaxNewSize are both specified we use these values.
 // No updates when the heap size changes. There is a special case when

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

@@ -287,17 +287,18 @@
           "The number of times we'll force an overflow during "             \
           "concurrent marking")                                             \
                                                                             \
-  experimental(uintx, G1DefaultMinNewGenPercent, 20,                        \
-          "Percentage (0-100) of the heap size to use as minimum "          \
-          "young gen size.")                                                \
-                                                                            \
-  experimental(uintx, G1DefaultMaxNewGenPercent, 80,                        \
-          "Percentage (0-100) of the heap size to use as maximum "          \
-          "young gen size.")                                                \
-                                                                            \
-  experimental(uintx, G1OldCSetRegionLiveThresholdPercent, 90,              \
-          "Threshold for regions to be added to the collection set. "       \
-          "Regions with more live bytes than this will not be collected.")  \
+  experimental(uintx, G1NewSizePercent, 20,                                 \
+          "Percentage (0-100) of the heap size to use as default "          \
+          "minimum young gen size.")                                        \
+                                                                            \
+  experimental(uintx, G1MaxNewSizePercent, 80,                              \
+          "Percentage (0-100) of the heap size to use as default "          \
+          " maximum young gen size.")                                       \
+                                                                            \
+  experimental(uintx, G1MixedGCLiveThresholdPercent, 90,                    \
+          "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,                                     \
           "Amount of space, expressed as a percentage of the heap size, "   \