查看linux上java内存情况的相关命令

Java 8 takes more than 1/64th of your physical memory for your Xmssize (Minimum HeapSize) and less than 1/4th of your physical memory for your -Xmxsize (Maximum HeapSize).

默认最大是1/4， 默认最小是1/64的物理内存。

Java 8 takes more than 1/64th of your physical memory for your Xmssize (Minimum HeapSize) and less than 1/4th of your physical memory for your -Xmxsize (Maximum HeapSize).

You can check the default Java heap size by:

In Windows:

java -XX:+PrintFlagsFinal -version | findstr /i "HeapSize PermSize ThreadStackSize"

In Linux:

java -XX:+PrintFlagsFinal -version | grep -iE 'HeapSize|PermSize|ThreadStackSize'

 

参看所有java进程占内存的情况：

top -b -n 1 | grep java| awk '{print "PID:"$1",mem:"$6",CPU percent:"$9"%","mem percent:"$10"%"}'

 

 

linux调整tomcat的内存大小：

找到tomcat的目录下bin/catalina.sh, 在最开始加入：

JAVA_OPTS="-Xms2g -Xmx44g"