linux /proc/pid/smaps各字段含义

r囧r小猫 2022-08-05 07:26 340阅读 0赞

# /proc/$PID/smaps #

![这里写图片描述][20150610195455816]  
第一行：  
**08048000-080bc000** 地址空间的开始地址 - 结束地址  
**r-xp** 属性。前三个是rwx（读、写、可执行）,如果不具有则为“-”。最后一个是p/s(私有/共享)  
**00000000** 偏移量。如果这段内存是从文件里映射过来的，则偏移量为这段内容在文件中的偏移量。如果不是从文件里面映射过来的则为0.  
**03:02** If the region was mapped from a file, this is the major and minor device number (in hex) where the file lives.  
**13130** If the region was mapped from a file, this is the file number.  
**/bin/bash** If the region was mapped from a file, this is the name of the file. This field is blank for anonymous mapped regions. There are also special regions with names like \[heap\], \[stack\], or \[vdso\]. \[vdso\] stands for virtual dynamic shared object. It’s used by system calls to switch to kernel mode.

**Rss**\-Resident Set Size 实际使用物理内存（包含共享库占用的内存）  
Rss=Shared\_Clean+Shared\_Dirty+Private\_Clean+Private\_Dirty  
**Pss** 实际使用的物理内存（按比例包含共享库占用的内存）。比如四个进程共享同一个占内存1000MB的共享库，每个进程算进250MB在Pss。  
**Shared\_Clean** 、 **Shared\_Dirty** 、 **Private\_Clean**、 **Private\_Dirty**  
（shared/private）共享和私有  
一个页的clean字段表示没有更改此页，当发生换页时不用写回。dirty表示更改了此页，当发生换页时要写回磁盘。此处这四个值是遍历页表中各个页后得到的。  
“**Referenced**” indicates the amount of memory currently marked as referenced or accessed. “**Anonymous**” shows the amount of memory that does not belong to any file. Even a mapping associated with a file may contain anonymous pages: when MAP\_PRIVATE and a page is modified, the file page is replaced by a private anonymous copy. “**Swap**” shows how much would-be-anonymous memory is also used, but out on swap.

[20150610195455816]: /images/20220805/f0cc30a491ea43e096f4f3c7d0d00a5c.png