memory.memsw.limit_in_bytes: Invalid argument

Question

I have a Debian 10 server and I am trying to limit the memory + swap of a user using cgroups2.

Using memory.limit_in_bytes works fine, but I want to limit the memory+swap using memory.memsw.limit_in_bytes which isn't working.

I get this error when I run cgconfigparser:

root@server:~# cgconfigparser -l /etc/cgconfig.conf
Error: failed to set /sys/fs/cgroup/memory/group1/memory.memsw.limit_in_bytes: Invalid argument
cgconfigparser; error loading /etc/cgconfig.conf: Failed to remove a non-empty group
root@server:~#

Here is the group:

group group1 {
  memory {
    memory.memsw.limit_in_bytes = 512m;
  }
}

Any idea on what's wrong?

EDIT: I've enabled cgroups memory and swapaccount in the GRUB command already but still the issue occurs.

Could you post the additions to the kernel commandline you added to GRUB, and also the output of `cat /proc/cmdline` please? Apart from that, try as mentioned in this answer: https://unix.stackexchange.com/a/125024/83329 — doktor5000, Apr 12 '20 at 09:18
@doktor5000 - `root@server:~# cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-5.4.0-0.bpo.2-amd64 root=/dev/sda2 ro rd.driver=raid1,ahci,dm_mod,part_gpt domdadm dolvm rd.lvm.vg=vg00 rd.lvm.lv=vg00/usr console=ttyS0,57600 console=tty0 net.ifnames=0 biosdevname=0 quiet cgroup_enable=memory swapaccount=1` — Mario, Apr 12 '20 at 09:29
Just to be clear: you say you're trying to limit a user using cgroup v2, but this is legacy cgroup v1, which has a significant number of deficiencies :-) — Chris Down, Apr 12 '20 at 11:46
@ChrisDown - The system supports cgroup v2 but idk why it uses v1 — Mario, Apr 12 '20 at 12:04
It's not the system, you're explicitly using cgroupv1 with that stanza. For cgroupv2, have a look at e.g. https://facebookmicrosites.github.io/cgroup2/docs/memory-controller.html you would probably want `memory.max` and `memory.swap.max` @ChrisDown good catch ;) — doktor5000, Apr 12 '20 at 12:09
@doktor5000 Heh, linked to my own documentation ;-) If your system is forcing v1 controllers, you might want to use `cgroup_no_v1=all` on the kernel command line. — Chris Down, Apr 12 '20 at 12:12

Mario · Accepted Answer · 2020-04-12T11:25:34.993

Thanks to @doktor5000 for providing the answer Limit memory usage for a single Linux process

I concluded the following from that answer: memory.limit_in_bytes must be set before memory.memsw.limit_in_bytes, and memory.memsw.limit_in_bytes must be bigger than or equal to memory.limit_in_bytes

So in my case, this group configuration worked:

group group1 {
  memory {
    memory.limit_in_bytes = 512m;
    memory.memsw.limit_in_bytes = 512m;
  }
}

which seens to limit the memory+swap of the user to 512MB. I've tested it with https://github.com/julman99/eatmemory

memory.memsw.limit_in_bytes: Invalid argument

1 Answers1