src/hotspot/share/runtime/globals.hpp

@@ -123,14 +123,17 @@
                                                                              \
    product(bool, UseCompressedOops, false,                                   \
            "Use 32-bit object references in 64-bit VM. "                     \
            "lp64_product means flag is always constant in 32 bit VM")        \
                                                                              \
-   product(bool, UseCompressedClassPointers, false,                          \
+   product(bool, UseCompressedClassPointers, true,                           \
            "Use 32-bit class pointers in 64-bit VM. "                        \
            "lp64_product means flag is always constant in 32 bit VM")        \
                                                                              \
+   product(bool, UseCompactObjectHeaders, true, EXPERIMENTAL,                \
+                 "Use 64-bit object headers instead of 96-bit headers")      \
+                                                                             \
    product(int, ObjectAlignmentInBytes, 8,                                   \
            "Default object alignment in bytes, 8 is minimum")                \
            range(8, 256)                                                     \
            constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
  

@@ -144,10 +147,11 @@
                             notproduct,                                      \
                             range,                                           \
                             constraint)
  const bool UseCompressedOops = false;
  const bool UseCompressedClassPointers = false;
+ const bool UseCompactObjectHeaders = false;
  const int ObjectAlignmentInBytes = 8;
  
  #endif // _LP64
  
  #define RUNTIME_FLAGS(develop,                                              \

@@ -1054,11 +1058,11 @@
            "If true, error data is printed to stderr instead of a file")     \
                                                                              \
    product(bool, ErrorFileToStdout, false,                                   \
            "If true, error data is printed to stdout instead of a file")     \
                                                                              \
-   develop(bool, UseHeavyMonitors, false,                                    \
+   product(bool, UseHeavyMonitors, false, DIAGNOSTIC,                        \
            "(Deprecated) Use heavyweight instead of lightweight Java "       \
            "monitors")                                                       \
                                                                              \
    develop(bool, VerifyHeavyMonitors, false,                                 \
            "Checks that no stack locking happens when using "                \

@@ -1411,13 +1415,13 @@
            constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo)              \
                                                                              \
    product(size_t, CompressedClassSpaceSize, 1*G,                            \
            "Maximum size of class area in Metaspace when compressed "        \
            "class pointers are used")                                        \
-           range(1*M, 3*G)                                                   \
+           constraint(CompressedClassSpaceSizeConstraintFunc, AfterErgo)     \
                                                                              \
-   develop(size_t, CompressedClassSpaceBaseAddress, 0,                       \
+   product(size_t, CompressedClassSpaceBaseAddress, 0, DIAGNOSTIC,           \
            "Force the class space to be allocated at this address or "       \
            "fails VM initialization (requires -Xshare=off.")                 \
                                                                              \
    product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC,          \
            "Print metaspace statistics upon VM exit.")                       \

@@ -1974,10 +1978,16 @@
    develop(bool, VerifyCrossModifyFence,                                     \
            false AARCH64_ONLY(DEBUG_ONLY(||true)),                           \
               "Mark all threads after a safepoint, and clear on a modify "   \
               "fence. Add cleanliness checks.")                              \
                                                                              \
+   product(bool, HeapObjectStats, false, DIAGNOSTIC,                         \
+              "Enable gathering of heap object statistics")                  \
+                                                                             \
+   product(size_t, HeapObjectStatsSamplingInterval, 500, DIAGNOSTIC,         \
+              "Heap object statistics sampling interval (ms)")               \
+                                                                             \
    product(int, LockingMode, LM_LEGACY, EXPERIMENTAL,                        \
            "Select locking mode: "                                           \
            "0: monitors only (LM_MONITOR), "                                 \
            "1: monitors & legacy stack-locking (LM_LEGACY, default), "       \
            "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)")         \