我如何知道为Sun JVM启用了哪些默认设置？ [英] How do i know which default settings are enabled for Sun JVM?

问题描述

我想在我的JVM上尝试CompressedOops。不，我想知道它是否可以默认启用。我在debian / squeeze上运行这个jvm：

i want to try CompressedOops on my JVM. No I wonder if it might be enabled by default. I run this jvm on debian/squeeze:

$ java -version
java version "1.6.0_22"
Java(TM) SE Runtime Environment (build 1.6.0_22-b04)
Java HotSpot(TM) 64-Bit Server VM (build 17.1-b03, mixed mode)

有人说它默认启用，有人说它不是：

Some people say it is enabled by default, some say it is not:

来自： http://forums.yourkit.com/viewtopic.php?f=3&t=3185

是的，你是对的，我还检查了它
和压缩的哎呀未激活
默认情况下在Java6u21 64位，我做
不明白为什么它在我提供的
链接中这么说。

Yes, you are right, I also checked it and Compressed Oops is not activated by default in Java6u21 64-bit, I do not understand why it said so in the links I provided.

我尝试用jconsole / JMX检查它，但没有运气找到名为CompressedOops或类似的属性。

I tried to check it with jconsole/JMX but had no luck to find an attribute named CompressedOops or alike.

有谁知道我在哪里获得所有列表具有默认值的特定构建的jvm选项？

Does anybody know where i get a list of all jvm options for a specific build with their default values?

关于
Janning

regards Janning

推荐答案

你可以运行 -XX：+ PrintFlagsFinal 在JVM启动时打印所有标志的值。

You can run with -XX:+PrintFlagsFinal to print the values of all flags at startup of the JVM.

或者，您可以使用 jinfo 工具检查正在运行的JVM中的标志值：

Alternatively, you can use the jinfo tool to check the value of a flag in a running JVM:

> jinfo -flag UseCompressedOops 7364
-XX:+UseCompressedOops

使用 jps 找到流程的pid。

Use jps to find the pid of the process.

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