diff -r 92add02409c9 -r f177ddd59c60 src/share/vm/runtime/arguments.cpp
--- a/src/share/vm/runtime/arguments.cpp	Fri Apr 08 14:19:50 2011 -0700
+++ b/src/share/vm/runtime/arguments.cpp	Fri Apr 08 14:53:16 2011 -0700
@@ -243,6 +243,12 @@
   { "MaxLiveObjectEvacuationRatio",
                            JDK_Version::jdk_update(6,24), JDK_Version::jdk(8) },
   { "ForceSharedSpaces",   JDK_Version::jdk_update(6,25), JDK_Version::jdk(8) },
+  { "UseParallelOldGCCompacting",
+                           JDK_Version::jdk_update(6,27), JDK_Version::jdk(8) },
+  { "UseParallelDensePrefixUpdate",
+                           JDK_Version::jdk_update(6,27), JDK_Version::jdk(8) },
+  { "UseParallelOldGCDensePrefix",
+                           JDK_Version::jdk_update(6,27), JDK_Version::jdk(8) },
   { NULL, JDK_Version(0), JDK_Version(0) }
 };
 
@@ -799,26 +805,22 @@
 
   JDK_Version since = JDK_Version();
 
-  if (parse_argument(arg, origin)) {
-    // do nothing
-  } else if (is_newly_obsolete(arg, &since)) {
-    enum { bufsize = 256 };
-    char buffer[bufsize];
-    since.to_string(buffer, bufsize);
-    jio_fprintf(defaultStream::error_stream(),
-      "Warning: The flag %s has been EOL'd as of %s and will"
-      " be ignored\n", arg, buffer);
-  } else {
-    if (!ignore_unrecognized) {
-      jio_fprintf(defaultStream::error_stream(),
-                  "Unrecognized VM option '%s'\n", arg);
-      // allow for commandline "commenting out" options like -XX:#+Verbose
-      if (strlen(arg) == 0 || arg[0] != '#') {
-        return false;
-      }
-    }
+  if (parse_argument(arg, origin) || ignore_unrecognized) {
+    return true;
   }
-  return true;
+
+  const char * const argname = *arg == '+' || *arg == '-' ? arg + 1 : arg;
+  if (is_newly_obsolete(arg, &since)) {
+    char version[256];
+    since.to_string(version, sizeof(version));
+    warning("ignoring option %s; support was removed in %s", argname, version);
+    return true;
+  }
+
+  jio_fprintf(defaultStream::error_stream(),
+              "Unrecognized VM option '%s'\n", argname);
+  // allow for commandline "commenting out" options like -XX:#+Verbose
+  return arg[0] == '#';
 }
 
 bool Arguments::process_settings_file(const char* file_name, bool should_exist, jboolean ignore_unrecognized) {