Re: [RFC PATCH v2 09/17] sched: Introduce sched_class::pick_task()

From: Vineeth Remanan Pillai
Date: Fri Apr 26 2019 - 12:11:21 EST


>
> I didn't get around to reading the original discussion here, but how can
> that possibly be?
>
> I can see !se, in that case curr is still selected.
>
> I can also see !curr, in that case curr is put.
>
> But I cannot see !se && !curr, per the above check we know
> cfs_rq->nr_running != 0, so there must be a cfs task to find. This means
> either curr or se must exist.

This fix was suggested as a quick fix for a crash seen in v1. But
I agree with you that this should be a bug if it happens and should
be investigated. I have tried in v2 and can no longer reproduce the
crash. Will remove the check in v3.

Thanks