The customer test if Java -Xss option correctly reflected
by using the following program until OutOfMemoryError occurs.

public class ThreadTest extends Thread {
  static int tcnt = 0;
  public static void main(String[] args) {
    try {
      while (true) {
        ThreadTest x = new ThreadTest();
          x.start();
          tcnt++;
          System.out.println(tcnt);
      }
    } catch (Throwable e) {
      e.printStackTrace();
    }
  }

  public void run() {
    try {
      Thread.sleep(1000*3600);
    } catch (InterruptedException ie) {
      ie.printStackTrace();
    }
  }
}

They invoked this program by:

java -Xms2048m -Xmx2048m -XX:PermSize=128m -XX:MaxPermSize=128m -Xss<variable> ThreadTest

and checked the JVM process memory size from ps command VSZ/NLWP output.
Physical memory was 4GB.

The result of the test seems to be:

1. -Xss between 512k and 768k not seems to set correctly
2. memory usage amount is almost same with -Xss on RHEL,
   but far different on Solaris 8.