We aren't using PREEMPT (RT) (which is enabled with CONFIG_PREEMPT_RT), we are just using plain PREEMPT (which is enabled with CONFIG_PREEMPT) /proc/sys/kernel/kernel_preemption does not exist on the nits when using preempt. I thought it was my versioning that may have removed it but when I flashed a proper preempt kernel (with the uname showing it was preempt), that proc entry still wasn't there. Anyway, here is my patch to enable PREEMPT and trick the versioning: http://pastebin.com/ffc8f11b EDIT: I'd try that CONFIG_PREEMPT_RT patch but it has disappeared off the internet