> > whatever you call it, "enqueue for yielding" or "enqueue as a part of
> > sched_switch", you made dispatcher know the purpose of enqueue, didn't you?
> No. Dispatcher has the rule to not enqueue (by giving this job to
> sched_switch() ), but knows nothing about purposes.

do you mean that there can be schedulers which don't enqueue the lwp
in sched_switch?  if so, can you give me an example?

YAMAMOTO Takashi