CPU Affinity locks causing bottlenecking, all games

[CGEE47]

When gamemode was enabled, games were only using cores 8–11 out of my full 32-core setup. It's been locking CPU affinity.

I tried setting renice to 0, disabled GPU optimizations, to no avail. Only disabling gamemode stopped the affinity lock and brought performance back up.

On lower-core-count machines (like Steam Decks or typical AMD systems), it's probably less noticeable, hence why I haven't found anyone with a similar issue online.

Steps used to reproduce the behavior:

1. Launch gamemod with any game, on a high core-count system, I've got a 13900k.
2. View output of htop or any other cpu monitoring software, I also checked affinity of the processes, and it was fine without gamemode, but it didn't work with.

• OS and version: Arch on Zen 6.15.4
• GameMode Version v1.8.2

[Zoomer1988]

Can confirm. Was playing around today with running Cinebench r23 and noticed it wasn't running its CPU Multi Core test on all the cores. Disabling game mode in Lutris settings allows Cinebench to run on all the cores.

Same 13900k, Arch Linux, 6.15.5 kernel