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 17:38:49 +0800 |
| |
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?
Thanks, Kuai
| |