--- old/src/jdk.jcmd/share/classes/sun/tools/jmap/JMap.java	2020-04-25 22:41:21.465485145 +0800
+++ new/src/jdk.jcmd/share/classes/sun/tools/jmap/JMap.java	2020-04-25 22:41:21.281485964 +0800
@@ -176,7 +176,7 @@
                UnsupportedEncodingException {
         String liveopt = "-all";
         String filename = null;
-        String parallelthreadnum = null;
+        String parallel = null;
         String subopts[] = options.split(",");
         boolean set_all = false;
         boolean set_live = false;
@@ -197,9 +197,9 @@
                     usage(1); // invalid options or no filename
                 }
                 cmdline = add_option(cmdline, filename);
-            } else if (subopt.startsWith("parallelThreadNum=")) {
-               parallelthreadnum = subopt.substring(19);
-               if (parallelthreadnum == null) {
+            } else if (subopt.startsWith("parallel=")) {
+               parallel = subopt.substring("parallel=".length());
+               if (parallel == null) {
                     usage(1);
                }
                // Add "parallelThreadsNum=<>" for later check
@@ -311,10 +311,10 @@
         System.err.println("      live         count only live objects");
         System.err.println("      all          count all objects in the heap (default if one of \"live\" or \"all\" is not specified)");
         System.err.println("      file=<file>  dump data to <file>");
-        System.err.println("      parallelThreadNum=<number>  parallel threads number for heap iteration:");
-        System.err.println("                                  parallelThreadNum=0 default behavior, use predefined number of threads");
-        System.err.println("                                  parallelThreadNum=1 disable parallel heap iteration");
-        System.err.println("                                  parallelThreadNum=<N> use N threads for parallel heap iteration");
+        System.err.println("      parallel=<number>  parallel threads number for heap iteration:");
+        System.err.println("                                  parallel=0 default behavior, use predefined number of threads");
+        System.err.println("                                  parallel=1 disable parallel heap iteration");
+        System.err.println("                                  parallel=<N> use N threads for parallel heap iteration");
         System.err.println("");
         System.err.println("    Example: jmap -histo:live,file=/tmp/histo.data <pid>");
         System.exit(exit);