Messages in this thread | | | Subject | Re: [PATCH v2 4/4] block, bfq: consider request size in bfq_asymmetric_scenario() | From | "yukuai (C)" <> | Date | Wed, 15 Sep 2021 15:47:54 +0800 |
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On 2021/09/15 15:36, Paolo Valente wrote: > > >> Il giorno 7 set 2021, alle ore 13:29, yukuai (C) <yukuai3@huawei.com> ha scritto: >> >> On 2021/08/27 1:00, Paolo Valente wrote: >>>> Il giorno 6 ago 2021, alle ore 04:08, Yu Kuai <yukuai3@huawei.com> ha scritto: >>>> >>>> There is a special case when bfq do not need to idle when more than >>>> one groups is active: >>>> >>> Unfortunately, there is a misunderstanding here. If more than one >>> group is active, then idling is not needed only if a lot of symmetry >>> conditions also hold: >>> - all active groups have the same weight >>> - all active groups contain the same number of active queues >> >> Hi, Paolo >> >> I didn't think of this contition. >> >> It's seems that if we want to idle when more than one group is active, >> there are two additional conditions: >> >> - all dispatched requests have the same size >> - all active groups contain the same number of active queues >> > > Also the weights and the I/O priorities of the queues inside the > groups needs to be controlled, unfortunately. > >> Thus we still need to track how many queues are active in each group. >> The conditions seems to be too much, do you think is it worth it to >> add support to idle when more than one group is active? >> > > I think I see your point. The problem is that these states are > dynamic. So, if we suspend tracking all the above information while > more than one group is active, then we are with no state in case only > one group remains active.
Hi, Paolo
In this case, I'll drop the last two patches in the next iteration.
Thanks, Kuai
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