小弟在学习GC的过程中，遇到JVM参数未生效的问题，一时不知道怎么解决，请路过大神帮帮忙指点指点，小弟谢过！
运行环境为：Win7 64bit, 4 core.
1，程序如下
public class PSGCDirectOldDemo {
/**
* @para args
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
Thread.sleep(20000);
byte[] bytes = new byte[1024 * 1024 * 2];
byte[] bytes2 = new byte[1024 * 1024 * 2];
byte[] bytes3 = new byte[1024 * 1024 * 2];
System.out.println("ready to direct allocate to old");
Thread.sleep(3000);
byte[] bytes4 = new byte[1024 * 1024 * 4];
Thread.sleep(3000);
}
}
2, 编译后，使用java PSGCDirectOldDemo -Xms20M -Xmx20M -Xmn10M -XX:SurvivorRatio=8 -XX:+UseParallelGC 命令运行；
3，但是执行结果显示运行参数"-Xms20M -Xmx20M -Xmn10M -XX:SurvivorRatio=8 -XX:+UseParallelGC"并未生效， S0和S1都为5M，Eden为32M， SurvivorRatio=5/32也不为8.
C:\Users\Administrator.LB-20130824QUJC>jstat -gc 8436 240
S0C S1C S0U S1U EC EU OC OU PC PU YGC YGCT FGC FGCT GCT
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 655.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 6799.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 10895.5 85504.0 0.0 21504.0 2445.9 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 11551.0 85504.0 0.0 21504.0 2452.6 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 11551.0 85504.0 0.0 21504.0 2452.6 0 0.000 0 0.000 0.000
5120.0 5120.0 0.0 0.0 32768.0 11551.0 85504.0 0.0 21504.0 2452.6 0 0.000 0 0.000 0.000
请高手、大神帮帮忙看看，小生尚位初学，有很多东西还不怎么明白，先在此谢过！
原因已找到，个人粗心所致，参数位置颠倒造成的。。。