Vsync issues with Linux?

[jondecker76Participant]

I have Monkey2 running on Ubuntu 17.10

The only issue I’m seeing is that all of the bananas run so fast that it’s not even usable.  The spacechimp banana reports a near 4000 FPS.  Pretty much every single example runs crazy fast like this.

Is there a way to force vsync?

This is on a Lenovo thinkpad P70 laptop

[nerobotParticipant]

Look at Window::SwapInterval property.

Try to set it to 1.

[jondecker76Participant]

thanks for the reply

The spacechimps example already has SwapInterval set to 1, and everything still runs ungoverned. Maybe I’ll do a bug report

[HezkoreParticipant]

What HZ does your screen update at?

[jondecker76Participant]

xrandr reports everything should be around 60hz, so I’m not sure why this is happening

Monkey

viavacavi@viavacavi-ThinkPad-P70:~$ xrandr Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 DP-0 disconnected (normal left inverted right x axis y axis) DP-1 disconnected (normal left inverted right x axis y axis) DP-2 disconnected (normal left inverted right x axis y axis) DP-3 disconnected (normal left inverted right x axis y axis) DP-4 disconnected (normal left inverted right x axis y axis) DP-5 disconnected (normal left inverted right x axis y axis) eDP-1-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 382mm x 215mm 1920x1080 60.00*+ 59.93 1680x1050 59.95 59.88 1600x1024 60.17 1400x1050 59.98 1280x1024 60.02 1440x900 59.89 1280x960 60.00 1360x768 59.80 59.96 1152x864 60.00 1024x768 60.04 60.00 960x720 60.00 928x696 60.05 896x672 60.01 960x600 60.00 960x540 59.99 800x600 60.00 60.32 56.25 840x525 60.01 59.88 800x512 60.17 700x525 59.98 640x512 60.02 720x450 59.89 640x480 60.00 59.94 680x384 59.80 59.96 576x432 60.06 512x384 60.00 400x300 60.32 56.34 320x240 60.05

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37

viavacavi@viavacavi-ThinkPad-P70:~$ xrandr Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 DP-0 disconnected (normal left inverted right x axis y axis) DP-1 disconnected (normal left inverted right x axis y axis) DP-2 disconnected (normal left inverted right x axis y axis) DP-3 disconnected (normal left inverted right x axis y axis) DP-4 disconnected (normal left inverted right x axis y axis) DP-5 disconnected (normal left inverted right x axis y axis) eDP-1-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 382mm x 215mm    1920x1080     60.00*+  59.93      1680x1050     59.95    59.88      1600x1024     60.17      1400x1050     59.98      1280x1024     60.02      1440x900      59.89      1280x960      60.00      1360x768      59.80    59.96      1152x864      60.00      1024x768      60.04    60.00      960x720       60.00      928x696       60.05      896x672       60.01      960x600       60.00      960x540       59.99      800x600       60.00    60.32    56.25      840x525       60.01    59.88      800x512       60.17      700x525       59.98      640x512       60.02      720x450       59.89      640x480       60.00    59.94      680x384       59.80    59.96      576x432       60.06      512x384       60.00      400x300       60.32    56.34      320x240       60.05

[Mark SiblyKeymaster]

As far as I can work out, the problem is that vsync support is purely down to the graphics driver, and not all drivers support it. On my cheap and cheerful linux+ATI setup, SwapInterval=1 works fine – which I find mildly surprising because I’m sure I didn’t used to work…

I think this may be because I was running the prorietary ATI ‘fglrx’ (?) driver in the past, but have recently switched to the official ‘open source’ one, which seems to work really well these days. You might want to try this if possible, but if SwapInterval=1 doesn’t work all you can really do is use a timer instead – see spacechimps for a timer demo.

Can anyone shed any more light on this? SwapInterval=1 ultimately results in a single call to glxSwapIntervalEXT, so I’m not sure what else I can do to make it work.

[HezkoreParticipant]

I have a bunch of Ati cards and they all work with SwapInterval, so for me there’s no issue.
But isn’t there a way to get any error messages from things like glxSwapIntervalEXT?
Maybe something like GetLastError() in the Windows API.

Maybe that’s something Monkey2 needs btw, a global error/warning stack?
If an error or warning occurred somewhere it gets throw into a stack and the user can go through that if he wants.

Mark Sibly

…see spacechimps for a timer demo.

jondecker76

The spacechimps example already has SwapInterval set to 1, and everything still runs ungoverned

Even with a timer it runs too fast?
That’s even weirder…

[jondecker76Participant]

I’m on Nvidia with proprietary drivers, I could try the opensource one to see if there is a difference.

With a timer, everything does work properly, it’s the just vsync that doesn’t work.

[Mark SiblyKeymaster]

Try setting env var __GL_SYNC_TO_VBLANK=1?

http://us.download.nvidia.com/XFree86/Linux-x86/367.57/README/openglenvvariables.html

[jondecker76Participant]

I gave it a try Mark, no go. I tried setting it in the local shell and even through /etc/environment. I tried setting to both 0 and 1 with the same results. I’ll keep poking around and let you know if I find anything fruitful

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