Messages in this thread | | | Subject | Re: [PATCH v4 1/2] block, bfq: counted root group into 'num_groups_with_pending_reqs' | From | "yukuai (C)" <> | Date | Wed, 20 Oct 2021 19:53:49 +0800 |
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On 2021/10/20 17:43, Paolo Valente wrote: > > >> Il giorno 20 ott 2021, alle ore 11:38, yukuai (C) <yukuai3@huawei.com> ha scritto: >> >> On 2021/10/20 17:29, Paolo Valente wrote: >>>> Il giorno 20 ott 2021, alle ore 11:20, yukuai (C) <yukuai3@huawei.com> ha scritto: >>>> >>>> On 2021/10/20 16:51, Paolo Valente wrote: >>>> >>>>>> @@ -860,9 +870,25 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, >>>>>> struct bfq_queue *bfqq) >>>>>> { >>>>>> struct bfq_entity *entity = bfqq->entity.parent; >>>>>> + struct bfq_sched_data *sd; >>>>>> + >>>>>> + /* >>>>>> + * If the bfq queue is in root group, the decrement of >>>>>> + * num_groups_with_pending_reqs is performed immediately upon the >>>>>> + * deactivation of entity. >>>>>> + */ >>>>>> + if (!entity) { >>>>>> + entity = &bfqd->root_group->entity; >>>>>> + sd = entity->my_sched_data; >>>>>> + >>>>>> + if (!sd->in_service_entity) >>>>>> + bfq_clear_group_with_pending_reqs(bfqd, entity); >>>>>> + >>>>>> + return; >>>>>> + } >>>>>> >>>>>> for_each_entity(entity) { >>>>>> - struct bfq_sched_data *sd = entity->my_sched_data; >>>>>> + sd = entity->my_sched_data; >>>>>> >>>>>> if (sd->next_in_service || sd->in_service_entity) { >>>>>> /* >>>>>> @@ -880,7 +906,8 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, >>>>>> } >>>>>> >>>>>> /* >>>>>> - * The decrement of num_groups_with_pending_reqs is >>>>>> + * If the bfq queue is not in root group, >>>>>> + * the decrement of num_groups_with_pending_reqs is >>>>> I'm sorry if I didn't notice this before, but why do you postpone the >>>>> decrement only for queues not in root group? If I'm not missing >>>>> anything, the active (i.e., with pending reqs) state of the root group >>>>> is to be computed as that of ay other group. >>>> >>>> Hi, Paolo >>>> >>>> I thought if queue is in root group, then bfqq->entity.parent is NULL, >>>> and such case is handled above, which is separate from previous >>>> implementation for queues that are not in root group. >>>> >>>> Is this the wrong way to handle root group? >>>> >>> I think that, if we want to count also the root group among the active >>> ones, then the logic for tagging the root group as active must be the >>> same as the other groups. Or am I missing something? >> >> Hi, Paolo >> >> Currently, if queue is in root group, bfqq->entity.parent is NULL, and >> this makes it hard to keep the same logic. >> >> Can we store root_group->my_entity to bfqq->entity.parent if the queue >> is in root group? >> > > Any sensible implementation is ok for me. Usually, stuff for root > group is in the bfqd. >
I'll try to do implement that way,
Thanks, Kuai
> Thanks, > Paolo > >> Thanks, >> Kuai > > . >
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