Linux performance Test pmap command detail

Name:

 pmap - report memory map of a process( View the memory image information for the process )

usage

 pmap [ -x | -d ] [ -q ] pids...
    pmap -V

In meaning

 -x  extended    Show the extended format.  Display extension format 
    -d  device     Show the device format.   Display device format 
    -q  quiet     Do not display some header/footer lines.  Does not show the end of the head 
    -V  show version  Displays version of program.  Display version 

Extended format and device format fields:

Address: start address of map  Image starting address 
    Kbytes: size of map in kilobytes  The image size 
    RSS: resident set size in kilobytes  Resident set size 
    Dirty: dirty pages (both shared and private) in kilobytes  Dirty page size 
    Mode: permissions on map  Image permissions : r=read, w=write, x=execute, s=shared, p=private (copy on write) 
    Mapping: file backing the map , or '[ anon ]' for allocated memory, or '[ stack ]' for the program stack.  Image support file ,[anon] Allocated memory  [stack] Program stack 
    Offset: offset into the file  File offset 
    Device: device name (major:minor)  The device name 

For example:

View the device format for process 1

[root@C44 ~]# pmap -d 1
1:  init [5]          
Address  Kbytes Mode Offset      Device  Mapping
00934000   88 r-x-- 0000000000000000 008:00005 ld-2.3.4.so
0094a000    4 r---- 0000000000015000 008:00005 ld-2.3.4.so
0094b000    4 rw--- 0000000000016000 008:00005 ld-2.3.4.so
0094e000  1188 r-x-- 0000000000000000 008:00005 libc-2.3.4.so
00a77000    8 r---- 0000000000129000 008:00005 libc-2.3.4.so
00a79000    8 rw--- 000000000012b000 008:00005 libc-2.3.4.so
00a7b000    8 rw--- 0000000000a7b000 000:00000  [ anon ]
00a85000   52 r-x-- 0000000000000000 008:00005 libsepol.so.1
00a92000    4 rw--- 000000000000c000 008:00005 libsepol.so.1
00a93000   32 rw--- 0000000000a93000 000:00000  [ anon ]
00d9d000   52 r-x-- 0000000000000000 008:00005 libselinux.so.1
00daa000    4 rw--- 000000000000d000 008:00005 libselinux.so.1
08048000   28 r-x-- 0000000000000000 008:00005 init
0804f000    4 rw--- 0000000000007000 008:00005 init
084e1000   132 rw--- 00000000084e1000 000:00000  [ anon ]
b7f5d000    8 rw--- 00000000b7f5d000 000:00000  [ anon ]
bffee000   72 rw--- 00000000bffee000 000:00000  [ stack ]
ffffe000    4 ----- 0000000000000000 000:00000  [ anon ]
mapped: 1700K  writeable/private: 276K  shared: 0K
[root@C44 ~]# 

The value of the last 1 row

mapped represents the virtual address space mapped by the process, that is, the pre-allocated virtual memory size of the process, namely vsz out of ps

writeable/private represents the size of the private address space occupied by the process, which is the actual memory used by the process

shared represents the amount of memory Shared by processes and other processes

View the device format of process 1 without displaying the header and trailing lines

[root@C44 ~]# pmap -d -q 1
1:  init [5]          
00934000   88 r-x-- 0000000000000000 008:00005 ld-2.3.4.so
0094a000    4 r---- 0000000000015000 008:00005 ld-2.3.4.so
0094b000    4 rw--- 0000000000016000 008:00005 ld-2.3.4.so
0094e000  1188 r-x-- 0000000000000000 008:00005 libc-2.3.4.so
00a77000    8 r---- 0000000000129000 008:00005 libc-2.3.4.so
00a79000    8 rw--- 000000000012b000 008:00005 libc-2.3.4.so
00a7b000    8 rw--- 0000000000a7b000 000:00000  [ anon ]
00a85000   52 r-x-- 0000000000000000 008:00005 libsepol.so.1
00a92000    4 rw--- 000000000000c000 008:00005 libsepol.so.1
00a93000   32 rw--- 0000000000a93000 000:00000  [ anon ]
00d9d000   52 r-x-- 0000000000000000 008:00005 libselinux.so.1
00daa000    4 rw--- 000000000000d000 008:00005 libselinux.so.1
08048000   28 r-x-- 0000000000000000 008:00005 init
0804f000    4 rw--- 0000000000007000 008:00005 init
084e1000   132 rw--- 00000000084e1000 000:00000  [ anon ]
b7f5d000    8 rw--- 00000000b7f5d000 000:00000  [ anon ]
bffee000   72 rw--- 00000000bffee000 000:00000  [ stack ]
ffffe000    4 ----- 0000000000000000 000:00000  [ anon ]
[root@C44 ~]# 

View the extended format for process 1

[root@C44 ~]# pmap -x 1
1:  init [5]          
Address  Kbytes   RSS  Anon Locked Mode  Mapping
00934000   88    -    -    - r-x-- ld-2.3.4.so
0094a000    4    -    -    - r---- ld-2.3.4.so
0094b000    4    -    -    - rw--- ld-2.3.4.so
0094e000  1188    -    -    - r-x-- libc-2.3.4.so
00a77000    8    -    -    - r---- libc-2.3.4.so
00a79000    8    -    -    - rw--- libc-2.3.4.so
00a7b000    8    -    -    - rw---  [ anon ]
00a85000   52    -    -    - r-x-- libsepol.so.1
00a92000    4    -    -    - rw--- libsepol.so.1
00a93000   32    -    -    - rw---  [ anon ]
00d9d000   52    -    -    - r-x-- libselinux.so.1
00daa000    4    -    -    - rw--- libselinux.so.1
08048000   28    -    -    - r-x-- init
0804f000    4    -    -    - rw--- init
084e1000   132    -    -    - rw---  [ anon ]
b7f5d000    8    -    -    - rw---  [ anon ]
bffee000   72    -    -    - rw---  [ stack ]
ffffe000    4    -    -    - -----  [ anon ]
-------- ------- ------- ------- -------
total kB  1700    -    -    -
[root@C44 ~]# 

The loop displays the last line of the device format for process 3066, at a 2-second interval,

[root@C44 ~]# while true; do pmap -d 3066 | 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

conclusion