Tasks priority and time slice

Hi, I am running two para-virtualized OS on L4RE. I would like to define tasks priority and time slice. The real time scheduling extensions does not seem to be implemented on ARM. But I have find this code in a Ned example: scheduler = L4.Env.mem_alloc:create(L4.Proto.Scheduler, 0x78, 0x70) I don't understand how to use second and third arguments. Regards, Pierre Larus