Fedora 39 Looks To Boost vm.max_map_count To Help Windows Games With Steam Play

[phoronix]

Phoronix: Fedora 39 Looks To Boost vm.max_map_count To Help Windows Games With Steam Play

Fedora 39 this autumn is looking at boosting its vm.max_map_count default to better match the behavior of SteamOS / Steam Deck and allowing more Windows games to run out-of-the-box with Steam Play...

https://www.phoronix.com/news/Fedora-39-VM-Max-Map-Count

[ridge]

I wonder if I'm an "interesting Linux gamer"

[milkylainen]

Sure. 64k could be increased a bit.
But I doubt that any game actually needs the limit raised to 2 BILLION+?

[jabl]

Sure. 64k could be increased a bit.
But I doubt that any game actually needs the limit raised to 2 BILLION+?

In the kernel SRC linked it's mentioned that some old userspace tools might not be able to handle more than what fits in an unsigned 16 bit value. Hence the old limit. So if you're going beyond that limit you might as well bump it to the 32-bit limit. Yes, that amount of VMA's is unlikely to work well, but it might not be a good place to control resource usage either.

[Steffo]

To the stars and much much beyond! 💫 ✨

[Mitch]

This is great. I additionally want to thank Michael for including the tip at the end for how to do this manually.

"Thankfully it's super easy adjusting the vm.max_map_count value anyhow, so interested Linux gamers running Fedora can easily do so with a command such as sudo sysctl -w vm.max_map_count=2147483642."


EDIT: It appears the line above is only temporary. See the reply to my post for how to make this change permanent.

[jntesteves]

This is great. I additionally want to thank Michael for including the tip at the end for how to do this manually.

"Thankfully it's super easy adjusting the vm.max_map_count value anyhow, so interested Linux gamers running Fedora can easily do so with a command such as sudo sysctl -w vm.max_map_count=2147483642."

That is only good for testing, as it's temporary until you reboot. To persist the setting, you have to write it to a file, for example:

# /etc/sysctl.d/90-override.conf
vm.max_map_count=2147483642

[juxuanu]

https://wiki.archlinux.org/title/Sysctl

[Vorpal]

What on earth are those games doing that they need tens of thousands of separate mappings?

[caligula]

What on earth are those games doing that they need tens of thousands of separate mappings?

Exactly. Does every malloc trigger this?