Linux pmap 进程内存分析

Linux pmap

[root@hankyoon ~]# pmap --help

Usage:
 pmap [options] PID [PID ...]

Options:
 -x, --extended              show details                             显示扩展格式
 -X                          show even more details
            WARNING: format changes according to /proc/PID/smaps
 -XX                         show everything the kernel provides
 -c, --read-rc               read the default rc
 -C, --read-rc-from=<file>   read the rc from file
 -n, --create-rc             create new default rc
 -N, --create-rc-to=<file>   create new rc to file
            NOTE: pid arguments are not allowed with -n, -N
 -d, --device                show the device format                   显示设备格式
 -q, --quiet                 do not display header and footer         不显示头尾行
 -p, --show-path             show path in the mapping
 -A, --range=<low>[,<high>]  limit results to the given range

 -h, --help     display this help and exit
 -V, --version  output version information and exit                   显示版本信息

For more details see pmap(1).

输出信息详解

Address        内存分配地址
Kbytes Mode    实际分配的内存大小
Offset         文件偏移
Device         设备名
Mapping        分配该内存的模块的名称,[anon]为已分配内存[stack]为程序堆栈
RSS            程序实际占用内存大小
Dirty          脏页大小
Mode           映像权限

输出最后一行的值详解

mapped：表示该进程映射的虚拟地址空间大小，也就是该进程预先分配的虚拟内存大小，即ps出的vsz

writeable/private：表示进程所占用的私有地址空间大小，也就是该进程实际使用的内存大小     

shared：表示进程和其他进程共享的内存大小

循环显示进程65078的设备格式的最后1行，间隔2秒

[root@hankyoon ~]#  while true; do pmap -d  65078 | tail -1; sleep 2; done
mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K

mapped: 5412K    writeable/private: 2028K    shared: 0K