As to whether or not POTUS truly knows what Sessions is doing, or not doing, is speculation. Perhaps Gen. Kelly gave POTUS lessons on opsec. IF this continues to drag on another 6 months to a year, it will be at that time prudent to demand Sessions be given a rocking chair at Lazy Acres.
Sessions has until Oct., 2018 to do a buncha unloading on the swamp (The FIB and DoJ in particular).