Originally Posted by AaronP
I should point out that this is not a bug: the spec does not require a particular maximum CPU usage when these functions are called. However, conserving a CPU would be a useful feature request, so I'll see if I can reproduce the issue and will file a feature request.
The same issue is present today.
I have written a simple openGL texturing benchmark application that can be copiled easily on Linux: http://pastebin.com/f5f9c076f
Running with: $ ./glfwTexture
top says the process consumes a CPU core to about 100%
Running with: $ __GL_YIELD="USLEEP" ./a.out
top says the process consumes a CPU core to about 5%
Both cases make about 30 FPS. The only difference is CPU usage.
I believe it is a bug. Is there a standard way to configure openGL to wait GPU idling the CPU so that other threads may use it?
I am using NVIDIA driver version 190.42 on "Linux xxx 2.6.31-15-generic #50-Ubuntu SMP Tue Nov 10 14:53:52 UTC 2009 x86_64 GNU/Linux". My GPU hardware is: GeForce 9400 GT