> Il giorno 25 ott 2021, alle ore 13:14, Jan Kara <jack@xxxxxxx> ha scritto: > > On Mon 25-10-21 09:58:11, Paolo Valente wrote: >>> Il giorno 7 ott 2021, alle ore 18:33, Paolo Valente <paolo.valente@xxxxxxxxxx> ha scritto: >>>> Il giorno 6 ott 2021, alle ore 19:31, Jan Kara <jack@xxxxxxx> ha scritto: >>>> >>>> Hello! >>>> >>>> Here is the third revision of my patches to fix how bfq weights apply on cgroup >>>> throughput and on throughput of processes with different IO priorities. Since >>>> v2 I've added some more patches so that now IO priorities also result in >>>> service differentiation (previously they had no effect on service >>>> differentiation on some workloads similarly to cgroup weights). The last patch >>>> in the series still needs some work as in the current state it causes a >>>> notable regression (~20-30%) with dbench benchmark for large numbers of >>>> clients. I've verified that the last patch is indeed necessary for the service >>>> differentiation with the workload described in its changelog. As we discussed >>>> with Paolo, I have also found out that if I remove the "waker has enough >>>> budget" condition from bfq_select_queue(), dbench performance is restored >>>> and the service differentiation is still good. But we probably need some >>>> justification or cleaner solution than just removing the condition so that >>>> is still up to discussion. But first seven patches already noticeably improve >>>> the situation for lots of workloads so IMO they stand on their own and >>>> can be merged regardless of how we go about the last patch. >>>> >>> >>> Hi Jan, >>> I have just one more (easy-to-resolve) doubt: you seem to have tested >>> these patches mostly on the throughput side. Did you run a >>> startup-latency test as well? I can run some for you, if you prefer >>> so. Just give me a few days. >>> >> >> We are finally testing your patches a little bit right now, for >> regressions with our typical benchmarks ... > > Hum, strange I didn't get your previous email about benchmarks. You're > right I didn't run startup-latency AFAIR. Now that you've started them, > probably there's no big point in me queuing them as well. So thanks for > the benchmarking :) > Hi Jan, we have executed a lot of benchmarking, on various hardware. No regression found! So, thank you very much for this important contribution, and: Acked-by: Paolo Valente <paolo.valente@xxxxxxxxxx> > Honza > -- > Jan Kara <jack@xxxxxxxx> > SUSE Labs, CR
