witold.baryluk+eac@gmail.com

Debian testing, kernel 6.0.0-rc4, mesa 22.2.0



Hi.

It is not actually a crash, but a performance issue.

Every 30 seconds, game stutters a lot for a second or two. Normally it runs 105 fps, but every 30 seconds, it frame times jump from 9-10ms to 100-150ms. Like a clockwork.

After analyzing this in depth, I excluded almost everything (desktop, kernel, mesa, dxvk, state and shader caches, proton). It is neither of these. I did notice that something in apex process openes /proc/pid/pagemap file EXACTLY when the stutter happens. This is exactly every 30 seconds. (or rather open; do something; close; sleep 30).


I tested many other games (native, windows with wine or proton, vulkan, d3d9, d3d11, dxvk, etc), and no other game shows this behavior. There is also nothing else on the system that induces this. I for example shut down all processes, and daemon, even checked system activity using `forkstat`. Nothing correlates with stutter.

I also do not know of any Linux library that opens /proc/self/pagemap every 30 seconds. I do have a very long expirience with Linux. For example looking at dxvk, wine and glibc, there is zero references to pagemap manipulation (even reading).

wine does access /proc/self/pagemap file on Linux, in the get_working_set_ex (depending on compilation options).

Unfortunately I was not able to test other EAC enabled games on Linux. I tried Outriders, Knockout CIty, Rogue Company, but they all fail to load).

Feel free to contact me for more information.

Debian testing
Linux: kernel 6.0.0-rc4 and 5.19.4
Libc6: 2.34-7
Drivers: mesa 22.2.0 and mesa-git, RADV
CPU: Threadripper 2950X, 16 core
RAM: 256GB
GPU: Radeon 6900XT
dxvk v1.10.1 via Proton Experimental (7.10-100)