-XX：NewRatio和-XX：OldSize JVM标志的含义是什么？ [英] What is the meaning of the -XX:NewRatio and -XX:OldSize JVM flags?

问题描述

  java -XX：+ PrintCommandLineFlags -verbose：gc  - 使用下面的命令行启动我的java应用程序： XX：+ PrintGCDetails \ 
 -XX：+ UseConcMarkSweepGC -jar start.jar 
  

JVM支持以下选项：

  -XX：MaxNewSize = 87244800 -XX：MaxTenuringThreshold = 4 -XX：NewRatio = 7 
 -XX：NewSize = 21811200 -XX：OldPLABSize = 16 -XX：OldSize = 65433600 
 -XX：+ PrintCommandLineFlags -XX：+ PrintGC -XX：+ PrintGCDetails 
 -XX：+ UseCompressedOops -XX ：+ UseConcMarkSweepGC -XX：+ UseParNewGC 
  

任何人都可以向我解释NewRatio和OldSize的含义吗？特别是OldSize是终身代的初始大小？

NewRatio是旧一代与年轻一代的比例值2意味着旧的最大大小将是年轻人的最大大小的两倍，即年轻人可以达到堆的1/3）。

OldSize不是一个的记录选项，但我认为这是占用空间的大小 http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html

I am starting my java app with the following command line :

java -XX:+PrintCommandLineFlags -verbose:gc -XX:+PrintGCDetails \
     -XX:+UseConcMarkSweepGC -jar start.jar

The JVM enables the following options:

-XX:MaxNewSize=87244800 -XX:MaxTenuringThreshold=4 -XX:NewRatio=7
-XX:NewSize=21811200 -XX:OldPLABSize=16 -XX:OldSize=65433600
-XX:+PrintCommandLineFlags -XX:+PrintGC -XX:+PrintGCDetails
-XX:+UseCompressedOops -XX:+UseConcMarkSweepGC -XX:+UseParNewGC

Can anyone explains me the meaning of NewRatio and OldSize ? In particular OldSize is the initial size of the tenured generation ?

解决方案

The NewRatio is the ratio of old generation to young generation (e.g. value 2 means max size of old will be twice the max size of young, i.e. young can get up to 1/3 of the heap).

The OldSize is not one of the documented options, but I assume it's the size of the tenured space http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html

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