VSync broken when using GLX_ARB_create_context

Discussion created by TheFiddler on Mar 20, 2009
Linux drivers stop vsyncing with GLX_ARB_create_context. Legacy context creation (i.e. glXCreateContext) works fine.

I am developing a VR application where VSync is of utmost importance.

Ordinarily, I use glXSwapIntervalSGI to enable VSync. Everything seems to work fine as long as I create the OpenGL context with glXCreateContext. If I try to use glXCreateContextAttribsARB, VSync stops working completely (glXSwapIntervalSGI completes successfully, but VSync stays off). I cannot force VSync through the drivers either - setting VSync to "always on" does not change anything.

This is on linux x86_64, using an HD 4850 (the final program will run on workstation graphics). Problem is reproducible with Catalyst 9.1, 9.2 and the 9.4 beta.

Any insight? Is this a known bug?