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Mulyadi Santosa [mulyadi.santosa at gmail.com]
Hi all
Recent Linux kernel versions allow us to see how much memory owned by a process is swapped out. All you need to do is the PID of the process and grab the output of related /proc entry:
$ cat /proc/<pid of your process>/smaps | grep Swap
To easily sum up all these per-process swap output, simply use below awk script:
$ cat /proc/<pid of your process>/smaps | grep Swap | awk '{ SUM +=
$2 } END { print SUM }'
the unit is in kilobyte.
PS: This is confirmed in Fedora 9 using Linux kernel version 2.6.27.21-78.2.41.fc9.i686.
regards,
Mulyadi.
Ben Okopnik [ben at linuxgazette.net]
> From: Mulyadi Santosa <mulyadi.santosa@gmail.com>
>
> Hi all
>
> Recent Linux kernel versions allow us to see how much memory owned by
> a process is swapped out. All you need to do is the PID of the process
> and grab the output of related /proc entry:
> $ cat /proc/<pid of your process>/smaps | grep Swap
>
> To easily sum up all these per-process swap output, simply use below awk script:
> $ cat /proc/<pid of your process>/smaps | grep Swap | awk '{ SUM +=
> $2 } END { print SUM }'
> the unit is in kilobyte.
>
> PS: This is confirmed in Fedora 9 using Linux kernel version
> 2.6.27.21-78.2.41.fc9.i686.
Not confirmed in Ubuntu 9.04. Here's what my system looks like after I've launched a whole bunch of Firefox and GIMP processes:
### Swap state ben@Jotunheim:~$ swapon -s Filename Type Size Used Priority /dev/sda5 partition 2996080 2320 -1
### Top 10 swap hogs, roughly ben@Jotunheim:~$ ps hk-size -eo pid,size,cmd|head 17435 160344 /usr/lib/firefox-3.0.10/firefox 2853 36032 spamd child 3689 34724 /usr/lib/bonobo-activation/bonobo-activation-server --ac-activate --ior-output-fd=19 18392 33540 gimp 3687 29708 nautilus 3669 25264 /usr/lib/gvfs//gvfs-fuse-daemon /home/ben/.gvfs 2486 24240 /usr/sbin/spamd --create-prefs --max-children 5 --helper-home-dir -d --pidfile=/var/run/spamd.pid 13411 24240 spamd child 3777 20680 /usr/lib/gnome-applets/mixer_applet2 --oaf-activate-iid=OAFIID:GNOME_MixerApplet_Factory --oaf-ior-fd=26 3645 18180 /usr/bin/pulseaudio --start
### Loop over the PIDs and sum up the swap lines;
### 'awk' invocation modified slightly to show PIDs.
ben@Jotunheim:~$ for n in `ps hk-size -eo size,pid|sed '11,$d;s/.* //'`
> do
> awk -v pid=$n '/^Swap/{a+=$1}END{printf "%-5d: %d\n",pid,a}' /proc/$n/smaps
> done
17435: 0
2853 : 0
3689 : 0
18392: 0
3687 : 0
3669 : 0
2486 : 0
13411: 0
3777 : 0
3645 : 0
In fact, there's not a single process on the system that shows a 'Swap' line that's greater than 0:
ben@Jotunheim:~$ awk -v name="$n" '/^Swap/{if ($2>0)print $2}' /proc/[0-9]*/smaps
ben@Jotunheim:~$
Sorry, Mulyadi - that one didn't pan out.
-- * Ben Okopnik * Editor-in-Chief, Linux Gazette * http://LinuxGazette.NET *
David Richardson [dsrich at ieee.org]
Ben Okopnik wrote:
> Sorry, Mulyadi - that one didn't pan out.
Doesn't work under Ubuntu 8.10, either.
-- David Richardson \ Imagine Whirled Peas dsrich@ieee.org \ These are my opinions - nobody else wants them.
Mulyadi Santosa [mulyadi.santosa at gmail.com]
Hmmm....I began to think that this swap accounting is only included in Fedora kernel tree only....
Sadly, I only have Fedora installation here to test. If I have time, I'll see if this swap accounting patch is already merged in mainline kernel.
regards,
Mulyadi.