-------- Original Message --------
On 3/25/24 4:10 AM, Robin Candau
Hi everyone,
I'm writing this mail as proposal to increase the default `vm.max_map_count` [1] value in Arch Linux.
The default `vm.max_map_count` 65530 value is making some Windows games crash (or even prevent them to start at all) while being played through Wine or Steam Play (Proton). Examples are (but not limited to) Star Citizen, THE FINALS, Hogwarts Legacy, DayZ or Counter-Strike 2 (see [2] for a list of bug reported to Valve for these games on that matter).
In that regard, SteamOS is shipping an increased `vm.max_map_count` default value to address the above issue and numerous distributions have since then decided to implement that change on their side as well, such as Fedora [3], NixOS [4] and, more recently, Ubuntu [5].
While I'm aware that Arch is a user centric/DIY distro and everyone can set their own `vm.max_map_count` value fairly easily, shipping an increased value on our side would be a beneficial change to make in my opinion as it would result in a smoother gaming experience out of the box for our users without representing any downside/side effect (as far as I'm aware).
In terms of implementation, the change basically consists of shipping the following sysctl file:
``` # Increase the number of virtual memory areas that one process may request vm.max_map_count=1048576 ```
For reference, Fedora added it to their systemd package [6], while Ubuntu handled it at the procps level [7]. I personally don't have a strong opinion on the implementation way/place.
To sum up, I think this would be a reasonable and positive change to make to our distro. I'd be happy to read your thoughts (or eventual objection)! 😊
[1] https://docs.kernel.org/admin-guide/sysctl/vm.html#max-map-count [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2057792/comments/5 [3] https://fedoraproject.org/wiki/Changes/IncreaseVmMaxMapCount [4] https://github.com/NixOS/nixpkgs/pull/238459 [5] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2057792 [6] https://src.fedoraproject.org/rpms/systemd/blob/f39/f/10-map-count.conf [7] https://git.launchpad.net/ubuntu/+source/procps/commit/?h=applied/2%254.0.4-4ubuntu2&id=b4a4a046cf018a942598e55f3fbc7b5ef474f676
-- Regards, Robin Candau / Antiz
As stated on Matrix, I am in favor of this change. Though Arch is indeed a distribution for tinkerers, of course, this change sets up a reasonable default that saves time for each tinkerer who just wants their favorite games to work properly. Given that other distributions that tend towards more conservative approaches to defaults changes are implementing this, it should be a safe change to make. Campbell