jinfo是jdk自带的命令，用来查看、修改jvm的配置参数。
[weblogic@host bin]$ jinfo
-bash: jinfo: command not found
[weblogic@host bin]$ ./jinfo
Usage:
jinfo [option] <pid>
(to connect to running process)
jinfo [option] <executable <core>
(to connect to a core file)
jinfo [option] [server_id@]<remote server IP or hostname>
(to connect to remote debug server)
where <option> is one of:
-flag <name> to print the value of the named VM flag
-flag [+|-]<name> to enable or disable the named VM flag
-flag <name>=<value> to set the named VM flag to the given value
-flags to print VM flags
-sysprops to print Java system properties
<no option> to print both of the above
-h | -help to print this help message
查看jvm的参数
jinfo -flags process_id
查看java系统参数
jinfo -sysprops process_id