On Fri, Oct 23, 2020 at 05:31:18PM -0400, Joel Fernandes wrote: > BTW, as further optimization in the future, isn't it better for the > schedule() loop on 1 HT to select for all HT *even if* need_sync == false to > begin with? i.e. no cookied tasks are runnable. > > That way the pick loop in schedule() running on other HTs can directly pick > what was pre-selected for it via: > if (rq->core->core_pick_seq == rq->core->core_task_seq && > rq->core->core_pick_seq != rq->core_sched_seq && > rq->core_pick) > .. which I think is more efficient. Its just a thought and may not be worth > doing.
I'm not sure that works. Imagine a sibling doing a wakeup (or sleep) just after you done your core wide pick. Then it will have to repick and you end up with having to do 2*nr_smt picks instead of 2 picks.
