Apparently, the SteamOS already has a larger vm.max_map_count by default. Can we do the same on upcoming version of Ubuntu.
https://github.com/ValveSoftware/Proton/issues/6510#issuecomment-1422699309
Seems to help with some games’ stability (e.g. Hogwarts Legacy).
Hi, many users, including myself, have observed improved game stability by increasing the vm.max_map_count kernel parameter. Games like Counter-Strike 2, Hogwarts Legacy, DayZ, Payday 2, and Star Citizen greatly benefit from a higher vm.max_map_count , experiencing no more crashes and better performance.
SteamOS and Fedora has already adopted a higher default value for this parameter, leading to a noticeably smoother gaming experience. Implementing a similar adjustment in the next Ubuntu release could provide a substantial boost to the gaming community, making Ubuntu an even more attractive platform for gamers.
Thank you for considering this enhancement. Your efforts to improve the gaming ecosystem on Linux are greatly appreciated.
Regards,
Vincent.
may be related to next Ubuntu cycle, but fs.inotify.max_user_instances is leaking due some PowerShell extemporare and increasing it temporarily fixed it for a few years… silly
I’m surprised /proc/sys/vm/max_map_count defaults to 65530, or that there’s a limit at all. It makes sense some apps would crash.
Is it too late to fix this in 24.04?
It should may be fixed in vanilla kernel, but /proc was deprecated 20 years ago…
mv /proc/* /sys/deprecated/
ctrl+F or ctrl+H and replace all occurences in kernel and force update all progs similar way 
and let kernel devs work on this 
According to Brodie Robertson on YouT, Canonical will have this update in 24. I have not independently confirmed this.
I found this in a Stack forum and it worked for me on Ubuntu Server 22.04.4 LTS; Kernel 6.5.0-27-lowlatency
# sudo sysctl -w vm.max_map_count=262144
Then for the persistence configuration. Must be LOGGED IN as root. Using sudo for this command while logged in as <user> will be denied.
# sudo su
# echo "vm.max_map_count=262144" >> /etc/sysctl.conf
Then reboot with your favorite method.
To check if changed...
# cat /proc/sys/vm/max_map_count
Hope this helps.
In new 24.04 there are some hard kernel /etc/sysctl.conf.d weird default values which could be list via:
sysctl -a
including some weird security network settings but also max user processes or app armor settings… I would expect from netplan generate some healthy settings but that could also be kernel policies, but then in that case in Desktop I would eliminate some options from kernel or give such possibility :). We are not anymore in 1970… including some weird max user processes count on Desktop…
And these problems are maybe not only desktop oriented when there are a lot of enthusiasm on internet connections…
UPDATE
It looks as though Canonical has it defaulted at 1048576 for 24.04 on install.