[Solved]How to prevent an application from eating up all your RAM?

martinsz · 2009-09-14 00:12:30

Hi all,

I have a slightly specific question. I'm using my computer for numerical computations, which involve solving large (and, yes, I mean large) linear programs. Now, as I play with the code, and try out different setups or solvers, it happens that the problem just gets 'too big' from time to time, i.e. suddenly the program I run starts eating up all my RAM, and after it's done, it proceeds to do the same with all my swap space.
Now, I would like to prevent this. Ideally, I'd like to be able to just open gnome's system monitor, and kill the program. The problem is - once you've run out of normal RAM and operate on swap, doing pretty much anything takes ages, so I essentially have the option of waiting quite a while until the system monitor starts, or restarting (which isn't awesome either).
I was wondering if any of you can give me some hints as to how to solve this. I looked into the 'nice' documentation, but I'm not sure how exactly nice handles memory. What I would need specifically would be some way to prevent the program from using up all the RAM (so, p.e. let it use all the free ram besidey a few MB so I can still keep the system responsive, and then proceed to using swap).

Thanks for the help!

Best,
Martin

Last edited by martinsz (2009-09-15 00:39:45)

ataraxia · 2009-09-14 00:33:33

You should look at doing something with "ulimit" before starting the app.

thisoldman · 2009-09-14 02:14:05

Have you considered a virtual machine? Virtualbox is one example that allows you to set RAM limits for a guest OS. I haven't tried Virtualbox with Arch, but on my wife's Opensuse machine, it runs both Ubuntu and XP as guests.

jdhore · 2009-09-14 06:22:38

The other option (which is applicable only if you have more than 4GB of RAM) is to give yourself a small performance drop and install a PAE kernel. A PAE kernel is a 32-bit kernel. Normally a 32-bit OS will only support ~3.7GB of RAM, but with PAE enabled, linux will support 64GB of RAM on a 32-bit system. The most major upside of this is that a single application can only use 4GB of RAM, so no application can take over and eat all your RAM.

SanskritFritz · 2009-09-14 07:37:15

Also you could experiment with the swappiness option:
http://www.linuxvox.com/linux-articles/ … swappiness

Knute · 2009-09-14 11:54:34

Have you looked into pam? Pam has quite a bit of options to limit various things. Not quite sure how to set it up for this though.

martinsz · 2009-09-15 00:39:16

Hi!

Thanks for all your input!

I don't think I can use a virual machine (don't have the space to install another system + one of my solvers has a node-locked license..). The only thing I found in the pam documentation was setting the maximal amount of RAM I can use per session, so essentially it's the same as ulimit.
Setting my memory limit to whatever physical RAM I have available would work, in the sense that whenever the code exceeds the RAM, it will produce an error and stop.
I think I'll try setting my swappiness to 0. According to the documentation, this should prevent current applications (read: system-monitor) from being paged out to swap, which should mean that I can still access it quickly even though my program tanks.
Another, fairly simple solution I found is actually (and maybe I'm doing a bit of overkill here) giving the offending program a very high nice value (i.e. low priority), and system-monitor a very high one. It doesn't prevent system-monitor from being paged out to swap, I think, but at least it doesn't need to jostle for position in the main RAM once I want to use it, so the loading takes place much faster.

Thanks for the help!

Martin

Ranguvar · 2009-09-15 02:42:01

thisoldman wrote:

Have you considered a virtual machine? Virtualbox is one example that allows you to set RAM limits for a guest OS. I haven't tried Virtualbox with Arch, but on my wife's Opensuse machine, it runs both Ubuntu and XP as guests.

Overkill for a task like this, a chroot would be better ;)

thisoldman · 2009-09-15 03:36:19

I like the chroot idea.

Arch Linux

#1 2009-09-14 00:12:30

[Solved]How to prevent an application from eating up all your RAM?

#2 2009-09-14 00:33:33

Re: [Solved]How to prevent an application from eating up all your RAM?

#3 2009-09-14 02:14:05

Re: [Solved]How to prevent an application from eating up all your RAM?

#4 2009-09-14 06:22:38

Re: [Solved]How to prevent an application from eating up all your RAM?

#5 2009-09-14 07:37:15

Re: [Solved]How to prevent an application from eating up all your RAM?

#6 2009-09-14 11:54:34

Re: [Solved]How to prevent an application from eating up all your RAM?

#7 2009-09-15 00:39:16

Re: [Solved]How to prevent an application from eating up all your RAM?

#8 2009-09-15 02:42:01

Re: [Solved]How to prevent an application from eating up all your RAM?

#9 2009-09-15 03:36:19

Re: [Solved]How to prevent an application from eating up all your RAM?

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