Pmap provide memory map of a process, The pmap command display the memory usage map of a process or multiple processes. Pmap reports information about the address space or memory usage map of a process. Pmap is actually a Sun OS command and Linux supports only very limited number of features. But it is very helpful for finding the complete address space of a process. To check [memory usage of process][1] we need PID or unique process ID of running process, we can get PID from /proc or regular commands like top or ps.
### Syntax or usage ###
#pmap PID
or
#pmap [options] PID
In outout it display total address, kbytes, mode and mapping.
### Options ###
-x extended Show the extended format.
-d device Show the device format.
-q quiet Do not display some header/footer lines.
-V show version Displays version of program.
### Memory usage map of single process ###
[root@info ~]# pmap 1013
1013: /usr/sbin/sshd
00110000 1480K r-x– /usr/lib/libcrypto.so.1.0.0
00282000 80K rw— /usr/lib/libcrypto.so.1.0.0
00296000 12K rw— [ anon ]
00299000 36K r-x– /lib/libkrb5support.so.0.1
002a2000 4K rw— /lib/libkrb5support.so.0.1
002a3000 16K r-x– /lib/libplc4.so
002a7000 4K rw— /lib/libplc4.so
002ab000 88K r-x– /lib/libaudit.so.1.0.0
002c1000 4K r—- /lib/libaudit.so.1.0.0
002c2000 4K rw— /lib/libaudit.so.1.0.0
002c3000 216K r-x– /lib/libgssapi_krb5.so.2.2
002f9000 4K rw— /lib/libgssapi_krb5.so.2.2
002fa000 808K r-x– /lib/libkrb5.so.3.3
003c4000 24K rw— /lib/libkrb5.so.3.3
003ca000 152K r-x– /lib/libk5crypto.so.3.1
003f0000 4K rw— /lib/libk5crypto.so.3.1
003f1000 92K r-x– /usr/lib/libnssutil3.so
00738000 4K r—- /lib/libresolv-2.12.so
00739000 4K rw— /lib/libresolv-2.12.so
0073a000 8K rw— [ anon ]
00825000 120K r-x– /lib/ld-2.12.so
00843000 4K r—- /lib/ld-2.12.so
00844000 4K rw— /lib/ld-2.12.so
0090d000 32K r-x– /lib/libwrap.so.0.7.6
00915000 4K rw— /lib/libwrap.so.0.7.6
00948000 484K r-x– /usr/sbin/sshd
009c1000 8K rw— /usr/sbin/sshd
009c3000 20K rw— [ anon ]
009e0000 92K r-x– /lib/libpthread-2.12.so
009f7000 4K r—- /lib/libpthread-2.12.so
total 8232K
### Memory usage map of multiple processes ###
We can check memory map of multiple processes by inserting multiple PIDs. Add multiple PIDs with adding space.
pmap 1013 1217 1118
### Extended memory map about a process ###
[root@info ~]# pmap -x 1013
1013: /usr/sbin/sshd
Address Kbytes RSS Dirty Mode Mapping
00110000 1480 92 0 r-x– libcrypto.so.1.0.0
00282000 80 80 80 rw— libcrypto.so.1.0.0
00296000 12 8 4 rw— [ anon ]
00299000 36 0 0 r-x– libkrb5support.so.0.1
002a2000 4 4 4 rw— libkrb5support.so.0.1
002a3000 16 0 0 r-x– libplc4.so
002a7000 4 4 4 rw— libplc4.so
002ab000 88 4 0 r-x– libaudit.so.1.0.0
002c1000 4 4 4 r—- libaudit.so.1.0.0
002c2000 4 4 4 rw— libaudit.so.1.0.0
002c3000 216 4 0 r-x– libgssapi_krb5.so.2.2
002f9000 4 4 4 rw— libgssapi_krb5.so.2.2
002fa000 808 4 0 r-x– libkrb5.so.3.3
003c4000 24 24 24 rw— libkrb5.so.3.3
003ca000 152 4 0 r-x– libk5crypto.so.3.1
003f0000 4 4 4 rw— libk5crypto.so.3.1
003f1000 92 0 0 r-x– libnssutil3.so
00408000 12 12 12 rw— libnssutil3.so
0040b000 12 0 0 r-x– libplds4.so
0040e000 4 4 4 rw— libplds4.so
——– ——- ——- ——- ——-
total kB 8232 –– -
Here Address, Kbyte, Dirty, RSS, mode and mapping containd information as below
### Extended and Device Format Fields ###
Address: start address of map
Kbytes: size of map in kilobytes
RSS: resident set size in kilobytes
Dirty: dirty pages (both shared and private) in kilobytes
Mode: permissions on map: read, write, execute, shared, private (copy on write)
Mapping: file backing the map, or ‘[ anon ]‘ for allocated memory, or ‘[ stack ]‘ for the program stack
