Contents

*I would generally not advise using this unless you have skill at debugging why OOM has spawned and also debugging kernel panics after they happen, from logs.*

It is possible to configure your kernel to panic when OOM is spawned, which in itself is not useful but, coupled with a kernel option for auto-rebooting a system when the kernel panics it can be a very useful tool.

Think before implementing this and use at your own risk, I take zero responsibility for you using this.

sudo sysctl vm.panic_on_oom=1
sudo sysctl kernel.panic=X # X is the amount of seconds to wait before rebooting

*DO NOT FORGET TO CHANGE X*

This will inject the changes in to a system that is currently running but will be forgotten on reboot so use the lines below to save permanently.

sudo echo "vm.panic_on_oom=1" >> /etc/sysctl.conf
sudo echo "kernel.panic=X" >> /etc/sysctl.conf

*X is the amount of seconds to wait before rebooting. DO NOT FORGET TO CHANGE X*

Testing

You can test the changes with a simple C program. Please note if you run this you do so at your own risk.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MB 10485760

int main(int argc, char *argv[]) {
    void *b = NULL;
    int c = 0;
    while(1) {
        b = (void *) malloc(MB);
        if (!b) {
            break;
        }
        memset(b, 10, MB);
        printf("Allocating %d MB\n", (++c * 10));
    }
    exit(0);
}

Compilation

You can download the source here.

To compile run the command below

gcc -O2 oom.c -o oom

Or download a pre-compiled version here.

Usage

And simply run it using

./oom

After a short period of time allocating and using 10MB chunks of memory your system should run out and restart.

Kura

Anarchist. Pessimist. Bipolar. Hacker. Hyperpolyglot. Musician. Ex pro gamer. Cunt. They/Them.

Kura

Join the discussion

View Source