LAST__PID_MASK
return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
return cpupid & LAST__PID_MASK;
return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);