de which would result in complete timekeeping wreckage. Now with the sysfs sanity check in place PIT cannot be selected again when the system is in oneshot mode. The system will not switch to one shot mode as long as PIT is installed because PIT is not suitable for one shot. The shutdown case which happens when the lapic timer is installed is covered by the fact that init_pit_clocksource() is called after the lapic timer take over and then does not install the PIT clocksource at all. We should have done the sanity checks back then, but ... This also solves the locking problem which was reported vs. the clocksource rework. LKML-Reference: Cc: Martin Schwidefsky Cc: john stultz Signed-off-by: Thomas Gleixner E’S”.x