Messages in this thread | | | Subject | Re: [PATCH 1/3] block, bfq: do not idle if only one cgroup is activated | From | "yukuai (C)" <> | Date | Mon, 26 Jul 2021 09:15:54 +0800 |
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On 2021/07/24 15:12, Paolo Valente wrote: > > >> Il giorno 14 lug 2021, alle ore 11:45, Yu Kuai <yukuai3@huawei.com> ha scritto: >> >> If only one group is activated, specifically >> 'bfqd->num_groups_with_pending_reqs == 1', there is no need to guarantee >> the same share of the throughput of queues in the same group. >> >> Thus change the condition from '> 0' to '> 1' in >> bfq_asymmetric_scenario(). > > I see your point, and I agree with your goal. Yet, your change seems > not to suffer from the following problem. > > In addition to the groups that are created explicitly, there is the > implicit root group. So, when bfqd->num_groups_with_pending_reqs == > 1, there may be both active processes in the root group and active > processes in the only group created explicitly. In this case, idling > is needed to preserve service guarantees. > > Probably your idea should be improved by making sure that there is > pending I/O only from either the root group or the explicit group. > > Thanks, > Paolo >
Hi,
Thanks for you advice, will do this in the next iteration.
Best regards, Kuai
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