On Thu, 27 May 2021 at 13:04, Odin Ugedal <odin@xxxxxxx> wrote: > > > 1st : ensure that cfs_rq->load_sum is not null if cfs_rq-> load_isn't too > > 2nd : call update_tg_load_avg() during child update so we will be sure > > to update tg_load_avg_contrib before removing the cfs from the list > > Ahh, yeah, with "1st" that would work. Yeah, that was my initial > implementation of the change, but I thought that it was better to keep > the logic away from the "hot path". We can verify this in > update_tg_cfs_load(), and then force update_tg_load_avg() inside For 1st problem, the way we were updating load_avg and load_sum, we were losing the sync between both value > __update_blocked_fair() when avg.load_avg is 0. (Given that this is > the only place where we can end up in this situation. I can update > this patch to do that instead. In fact, the update was already there but not always called (see the patchset i just sent) > > Another solution is to update avg.load_avg > inside__update_blocked_fair() when load_sum is 0, and then propagate > that with update_tg_load_avg(). This removes the logic from the hot > path all together. > > Not sure what the preferred way is. I have not found any other places > where this situation _should_ occur, but who knows.. > > Odin
