quoted

even if tv1<tv2 which can be true when time wraps (which is true
at least with PSCHED_TIME_SOURCE == JIFFIES)

No, psched_time_t cannot wrap for our life.

aarrrgh ... oh well I just found the PSCHED_WATCHER logic.
Then I'm sorry for my objection - I'll have to add
BUG_TRAP(!PSCHED_TLESS(tv1,tv2)) into my code ..

Thanks anyway,
devik