Advice and/or comment please.
I have two questions about CPU and memory usage during GLSL execution in the unix-like (multiuser and multitasking) OS, eg. Linux,FreeBSD.
First question:CPU usage
When executing computation intensive shader, CPU usage, which can be checked by “ps” command, shows 90% or more. If GPU does execute the computation, I think,CPU should be “idling”. What is the reason of high CPU usage?
Second question:Memory usage
When using texture, memory usage (VSZ and RSS colum in the result of “ps” command) grows by the size of the texture after glTexImage2D execution. This indicates the texture is not in the GPU memory but in the main memory? Is this true? That can not be true, I think. Then,the texture resides in both GPU and CPU. Is that so?
Thanks in advance