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I work on large-scale datasets. When testing new software, a script will sometimes sneak up on me, quickly grab all available RAM, and render my desktop unusable. I'd like a way to set a RAM limit for a process so that if it exceeds that amount, it will be killed automatically. A language-specific solution probably won't work, as I use all sorts of different tools (R, Perl, Python, Bash, etc).

So is there some sort of process-monitor that will let me set a threshold amount of RAM and automatically kill a process if it uses more?

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Last time i asked this (around a week ago) all the answers i got where "it's a bad idea, you shouldn't do it". Good Luck getting an answer though :) – Chriskin Jul 27 '11 at 17:09
@ Uri : At that thread i only got a partial (only for the cpu part of my question) - and not optimal - answer. He asks about RAM usage. – Chriskin Jul 27 '11 at 17:11
Uri, there's a complete lack of useful ideas in that thread. Posting a link to it isn't particularly helpful. – chrisamiller Jul 27 '11 at 17:12
Hrmm - this superuser thread seems to have a reasonable suggestion using ulimit: – chrisamiller Jul 27 '11 at 17:19

I would strongly advise not to do it. As suggested by @chrisamiller , setting ulimit will limit the RAM available with process.

But still if you are insisting then follow this procedure.

  1. Save the following script as

    if [ $# -ne 2 ];
        echo "Invalid number of arguments"
        exit 0
    while true;
        SIZE=$(pmap $1|grep total|grep -o "[0-9]*")
        echo "Process id =$1 Size = $SIZEMB MB"
        if [ $SIZEMB -gt $2 ]; then
            printf "SIZE has exceeded.\nKilling the process......"
            kill -9 "$1"
            echo "Killed the process"
            exit 0
            echo "SIZE has not yet exceeding"
        sleep 10
  2. Now make it executable.

    chmod +x
  3. Now run this script on terminal. Replace PROCID with actual process id and SIZE with size in MB.


    For example:

    ./ 132451 100

    If SIZE is 100 then process will be killed if its RAM usage goes up beyond 100 MB.

Caution: You know what are you trying to do. Killing process is not a good idea. If that process has any shutdown or stop command then edit the script and replace kill -9 command with that shutdown command.

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I fixed the formatting of the code for you. – Nathan Osman Jul 27 '11 at 19:08
i would consider putting little sleep there, for example sleep 0.5... – Denwerko Jul 27 '11 at 19:32
@George Edison How did you do that. When I tried to paste, it was giving me weirdly formatted text. Denwerko: Where would you like to put the sleep. I have already put a sleep of 10 seconds in the while loop – Amey Jah Jul 28 '11 at 15:21
Thanks for the solution, as noted below, I may check it out. Why all the dire warnings about killing processes, though? Cluster management software (LSF, PBS, et al) does this all the time when a process exceeds the amount of resources that it requested, with no dire consequences. I agree that this is not a good solution for new users who are likely to misapply it, but in the right circumstances, this can be quite useful. – chrisamiller Jul 28 '11 at 18:49
@chrisamiller I have put up a warning for future readers. In your case, you know the implications but future reader of this post might not be aware of such implications. – Amey Jah Jul 28 '11 at 19:46

I hate to be the guy who answers his own question, but this morning I found an alternative method, wrapped into a nice little utility. It'll limit CPU time or memory consumption:

I'm giving this one a shot first but upvotes to Amey Jah for the nice answer. I'll check it out if this one fails me.

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+1 Answering your own question is OK! – Tom Brossman Sep 25 '12 at 11:12

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