Check which processes are eating swap on Linux

linuxmemorymemory managementshellswap

To see some memory info I can watch it in top of through cat /proc/meminfo.
In /proc/meminfo I can see the swap usage of the whole system like this:

SwapCached:            4 kB
SwapTotal:      33460220 kB
SwapFree:       33460216 kB

But there can be I situation when almost all the swap is used (i.e. there is a too small piece of SwapFree). How can I figure out, which process(es) are eating this swap?

UPD: there is a too small piece of SwapFree basically means that there is some process(processes) which ate a lot of memory and didn't use it for a long time. I need to find such processes.

Best Answer

Run top
Press f to select displayed fields
Navigate down to SWAP using arrow keys
Hit Space - SWAP will become preceded by asterisk *
Press right arrow key - this will allow you to move SWAP to a convenient place in the listing, for example between %MEM and TIME+
Press q to return to top view

Step 5 isn't necessary, just convenience - without it SWAP will be showing up as the last entry of the list, after COMMAND.

Related Solutions

Linux – How to find out processes are using swap space

It is possible that multiple programs will be using the same swap area, so it will be reported twice.

There is no need to try to tell Linux to use the buffered area instead of swap--it's already very smart about what it's doing. If you're using 9gb of swap and 9gb of buffer, that's a good thing... that means Linux realizes that 9gb of stuff loaded into memory isn't being used actively, so it's more efficient to swap it to disk so that your buffer can grow larger, and improve your performance.

EDIT: If you add up all of the memory used by each process, you'll get much more than your physical RAM, too. This is due to shared libraries being used by multiple programs, as well as the way Linux handles forks--it doesn't duplicate the entire program in memory, it only duplicates the portions that differ between the two instances. In some cases, video memory can be shown as part of an X process--I think the old Voodoo3 cards did this. There may be other cases where "phantom" memory can show up in top, as well.

Linux – How to monitor memory usage for alarming purpose

Monitor system via free

[root@localhost ~]# free
          total       used       free     shared    buffers     cached
Mem:    2058240    1776788     281452          0      89780    1335840
-/+ buffers/cache:  351168    1707072
Swap:   4095992        100    4095892

Look at the -/+ buffers/cache line used and free

Monitor each process via /proc

I used this python script and /proc/pid/stat to monitor the memory of a process:

http://phacker.org/2009/02/20/monitoring-virtual-memory-usage-with-python/

you would probably like to translate something like this to c.

Limit resource for each process

or use ulimit / setrlimit

https://stackoverflow.com/questions/4983120/limit-memory-usage-for-a-single-linux-process

Best Answer

Related Solutions

Linux – How to find out processes are using swap space

Linux – How to monitor memory usage for alarming purpose

Related Question