unplayably bad stuttering in Unity/Mono games -- kernel regression?

axfelix · 2015-02-08 19:03:28

hi folks,

I'm fairly new to Arch, so bear with me here -- I'm running Gnome 3 with gdm, on the newest kernel / mesa / etc. from pacman. i5-4300Y with haswell graphics. have had this system running for a few weeks. when I first got it, everything was working OK, except I noticed that performance was implausibly bad in a handful of steam games -- like 2-3 frames per second bad. thinking on it, this seems to be only games that make use of the Unity or Mono middleware.

originally, I was running lightdm, and I thought it was narrowly possible that might be the issue, since I know upstream Gnome 3 doesn't really support anything other than gdm at this point. I switched to gdm, and the problem seemed to go away, but in hindsight, that might've been the same time as I updated from 3.18.2 to 3.18.3 or 3.18.4 (sorry I can't isolate this better, but I'm at least certain it was one of those).

however, the issue has come back this week, though I noticed I'm now on 3.18.5 -- so that might be it? I guess it no longer seems like it could be a lightdm issue, since I'm still on gdm, and I don't think it's an upstream mesa issue, since I'm running git mesa (newer than the bleeding edge unstable releases in arch sources) on my Ubuntu box which also uses Intel graphics, and it's not showing any of the same issues (but it's on a 3.13 kernel).

other games perform fine, so I don't think it's an issue with my GPU somehow underclocking itself. it's just Unity/Mono stuff. the games in question have not updated over this time period (or at least, all of them haven't updated the Unity/Mono runtimes such that this is plausibly the issue).

any thoughts? thanks!

axfelix · 2015-03-03 17:34:40

Sorry to bump this thread, but I'm still having the issue -- kernel's only been bumped from 3.18.5 to 3.18.6 in the past month, so I suppose it could be a kernel regression that's still unfixed, but I'm really skeptical that this could be a kernel problem. Anyone have any thoughts? It's a mystery to me...

I'll note that this machine is also powertopped, though the issue persists when I disable all of the powertop optimizations to test.

Last edited by axfelix (2015-03-03 17:35:36)

axfelix · 2015-03-12 19:20:34

System mono just updated and the regression is fixed. I assumed all the games were packing their own mono runtimes but I guess not! Hooray.

axfelix · 2015-04-05 23:30:52

Oddly, the regression has returned, despite Mono not having been updated since my last post ... I have no idea what's causing this regression at this point!

Rasi · 2015-04-06 10:08:55

try running steam (or whatever you use to start the games) with

PULSE_LATENCY_MSEC=60 steam

Arch Linux

#1 2015-02-08 19:03:28

unplayably bad stuttering in Unity/Mono games -- kernel regression?

#2 2015-03-03 17:34:40

Re: unplayably bad stuttering in Unity/Mono games -- kernel regression?

#3 2015-03-12 19:20:34

Re: unplayably bad stuttering in Unity/Mono games -- kernel regression?

#4 2015-04-05 23:30:52

Re: unplayably bad stuttering in Unity/Mono games -- kernel regression?

#5 2015-04-06 10:08:55

Re: unplayably bad stuttering in Unity/Mono games -- kernel regression?

Board footer