I am having trouble running OpenCL code on the CPU when the GDM is turned down.
I started off configuring a set of virtual machines having Ubuntu 10.04 minimal install. I could not get a platform when quering for OpenCL platforms/devices. If i were to run a desktop-env Ubuntu on the virtual machine OpenCL would return a platform. Also if i stop gdm and query for platforms application freezes in Ubuntu 11.04 (normal desktop not a virtual one).
I tried 2.4 SDK on the virtual machines and the freeze when gdm is off happens in 2.5 SDK. Hw configuration is Core i3 + 4GB + HD5470. I know it's an intel processor in this case but if gdm is on works flawless under both 2.4/2.5 SDK virtualized/normal.
I understand that OpenCL could not be run on GPUs with X Server down but would this also imply not even CPUs can't be used unless some output would be present ? If this is the case, why ?