In Linux how to tell how much memory processes are using

Question

I think I may have a memory leak in my LAMP application  memory gets used up  swap starts getting used  etc    If I could see how much memory the various processes are using  it might help me resolve my problem  Is there a way for me to see this information in  nix

User · Accepted Answer

Getting right memory usage is trickier than one may think. The best way I could find is:

echo 0 $(awk '/TYPE/ {print "+", $2}' /proc/`pidof PROCESS`/smaps) | bc

Where "PROCESS" is the name of the process you want to inspect and "TYPE" is one of:

Rss: resident memory usage, all memory the process uses, including all memory this process shares with other processes. It does not include swap;
Shared: memory that this process shares with other processes;
Private: private memory used by this process, you can look for memory leaks here;
Swap: swap memory used by the process;
Pss: Proportional Set Size, a good overall memory indicator. It is the Rss adjusted for sharing: if a process has 1MiB private and 20MiB shared between other 10 processes, Pss is 1 + 20/10 = 3MiB

Other valid values are Size (i.e. virtual size, which is almost meaningless) and Referenced (the amount of memory currently marked as referenced or accessed).

You can use watch or some other bash-script-fu to keep an eye on those values for processes that you want to monitor.

For more informations about smaps: http://www.kernel.org/doc/Documentation/filesystems/proc.txt.

User · Answer

Use ps to find the process id for the application  then use top -p1010  substitute 1010 for the real process id    The RES column is the used physical memory and the VIRT column is the used virtual memory - including libraries and swapped memory   More info can be found using  man top

User · Answer

Why all these complicated answers with various shell scripts  Use htop  it automatically changes the sizes and you can select which info you want shown and it works in the terminal  so it does not require a desktop  Example  htop -d8

User · Answer

Use    ps u  pidof  TASKS LIST  or ps u -C  TASK  ps xu --sort  mem  ps h -o pmem -C  TASK   Example   ps-of      ps u  pidof            ps-of firefox USER       PID  CPU  MEM    VSZ   RSS TTY      STAT START   TIME COMMAND const    18464  5 9  9 4 1190224 372496        Sl   11 28   0 33  usr lib firefox firefox    alias ps-mem  ps xu --sort  mem   sed -e  a -e  1p   q N 6   D ba     ps-mem  USER       PID  CPU  MEM    VSZ   RSS TTY      STAT START   TIME COMMAND const     3656  0 0  0 4 565728 18648          Sl   Nov21   0 56  usr bin python  usr lib ubuntuone-client ubuntuone-syncdaemon const    11361  0 3  0 5 1054156 20372         Sl   Nov25  43 50  usr bin python  usr bin ubuntuone-control-panel-qt const     3402  0 0  0 5 1415848 23328         Sl   Nov21   1 16 nautilus -n const     3577  2 3  2 0 1534020 79844         Sl   Nov21 410 02 konsole const    18464  6 6 12 7 1317832 501580        Sl   11 28   1 34  usr lib firefox firefox    ps h -o pmem -C firefox 12 7

User · Answer

You can use pmap   awk   Most likely  we re interested in the RSS memory which is the 3rd column in the last line of the example pmap output below  82564      pmap -x  lt pid gt   Address           Kbytes     RSS   Dirty Mode   Mapping        00007f9caf3e7000       4       4       4 r----  ld-2 17 so 00007f9caf3e8000       8       8       8 rw---  ld-2 17 so 00007fffe8931000     132      12      12 rw---      stack   00007fffe89fe000       8       8       0 r-x--      anon   ffffffffff600000       4       0       0 r-x--      anon   ----------------  ------  ------  ------ total kB          688584   82564    9592   Awk is then used to extract that value     pmap -x  lt pid gt    awk   total    print  4  K       The pmap values are in kilobytes  If we wanted it in megabytes  we could do something like this     pmap -x  lt pid gt    awk   total    print  4   1024  M

User · Answer

Use top or htop and pay attention to the  RES   resident memory size  column

User · Answer

I don t know why the answer seem so complicated    It seems pretty simple to do this with ps   mem                                                                                                               ps -eo rss pid euser args 100 --sort  mem   grep -v grep   grep -i      awk   printf  1 1024  MB    1     print        Example usage     mem mysql 0 511719MB 781 root  bin sh  usr bin mysqld safe 0 511719MB 1124 root logger -t mysqld -p daemon error 2 53516MB 1123 mysql  usr sbin mysqld --basedir  usr --datadir  var lib mysql --plugin-dir  usr lib mysql plugin --user mysql --pid-file  var run mysqld mysqld pid --socket  var run mysqld mysqld sock --port 3306

User · Answer

Thanks   I used this to create this simple bash script that can be used to watch a process and its memory usage     watch watchmypid sh     bin bash    PROCESSNAME changethistoyourprocessname MYPID  pidof  PROCESSNAME   echo            echo PID  MYPID echo  --------  Rss  echo 0   cat  proc  MYPID smaps    grep Rss   awk   print  2     sed  s          bc   Shared  echo 0   cat  proc  MYPID smaps    grep Shared   awk   print  2     sed  s          bc   Private  echo 0   cat  proc  MYPID smaps    grep Private   awk   print  2     sed  s          bc   Swap  echo 0   cat  proc  MYPID smaps    grep Swap   awk   print  2     sed  s          bc   Pss  echo 0   cat  proc  MYPID smaps    grep Pss   awk   print  2     sed  s          bc    Mem  echo   Rss    Shared    Private    Swap    Pss  bc -l   echo  Rss        Rss echo  Shared     Shared echo  Private    Private echo  Swap       Swap echo  Pss        Pss echo                      echo  Mem        Mem echo

User · Answer

First get the pid   ps ax   grep  process name    And then    top -p PID   You can watch various processes in the same time   top -p PID1 -p PID2

User · Answer

You can use pmap to report memory usage   Synopsis   pmap   -x   -d     -q   pids

User · Answer

The tool you want is ps  To get information about what java programs are doing   ps -F -C java    To get information about http   ps -F -C httpd   If your program is ending before you get a chance to run these  open another terminal and run   while true  do ps -F -C myCoolCode   sleep 0 5s   done

User · Answer

In case you don t have a current or long running process to track  you can use  usr bin time   This is not the same as Bash time  as you will see    Eg     usr bin time -f   M  echo  2028   This is  Maximum resident set size of the process during its lifetime  in Kilobytes   quoted from the man page   That is  the same as RES in top et al   There are a lot more you can get from  usr bin time      usr bin time -v echo  Command being timed   echo  User time  seconds   0 00 System time  seconds   0 00 Percent of CPU this job got  0  Elapsed  wall clock  time  h mm ss or m ss   0 00 00 Average shared text size  kbytes   0 Average unshared data size  kbytes   0 Average stack size  kbytes   0 Average total size  kbytes   0 Maximum resident set size  kbytes   1988 Average resident set size  kbytes   0 Major  requiring I O  page faults  0 Minor  reclaiming a frame  page faults  77 Voluntary context switches  1 Involuntary context switches  0 Swaps  0 File system inputs  0 File system outputs  0 Socket messages sent  0 Socket messages received  0 Signals delivered  0 Page size  bytes   4096 Exit status  0

User · Answer

More  elegant approach   echo  Memory usage for PID  lt  gt     for mem in  Private Rss Shared Swap Pss  do grep  mem  proc  lt pid gt  smaps   awk -v mem type   mem    i i  2  END  print mem type  memory usage  i    done

[linux] In Linux, how to tell how much memory processes are using?

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