Dne 31. 05. 23 v 19:14 Stefan Hajnoczi napsal(a): > On Wed, 31 May 2023 at 12:50, Lukáš Doktor <[email protected]> wrote: >> >> Dne 26. 05. 23 v 12:56 Stefan Hajnoczi napsal(a): >>> On Fri, 26 May 2023 at 04:07, Lukáš Doktor <[email protected]> wrote: >>>> >>>> Dne 25. 05. 23 v 17:21 Stefan Hajnoczi napsal(a): >>>>> On Thu, 25 May 2023 at 06:18, Lukáš Doktor <[email protected]> wrote: >>>>>> the perf-ci detected and bisected the 6d740fb - aio-posix: do not nest >>>>>> poll handlers - as a performance improvement when using multiple >>>>>> concurrent jobs and 4k (22%) as well as 1024k (63%) blocks on aarch64 >>>>>> (on a slow rotational disk). >>>>>> >>>>>> >>>>>> https://ldoktor.github.io/tmp/RedHat-virtlab-arm09/v8.0.0/150-improvement.html >>>>>> >>>>>> Based on the commit message I guess it's expected so take this just as a >>>>>> record of an improvement. >>>>> >>>>> The commit was not intended to change performance and I'm not sure why >>>>> it happens! >>>>> >>>> >>>> It had and today the x86_64 pipeline finished which shows similar >>>> improvement just not in read but rather in write instead and only for 4k >>>> blocks (~40%). For 1024k blocks I can see it scoring a bit better (~1.5%). >>>> Reads are too jittery to really tell anything on that machine. Anyway I >>>> have not done any thorough testing, just a bisection with the most >>>> significant setting. >>>> >>>> From around the same time I can see a NVMe regression in 4k writes, but >>>> first bisection job showed nothing. I'll increase the range and try again >>>> as each job since that day shows similar drop. >>> >> >> Hello Stefan, folks, >> >> the regression proved to be there and stably reproducible. With NVMe 4k >> writes with jobs=10 and iodepth=4 I can see a 50% regression on my machine: >> >> >> https://ldoktor.github.io/tmp/RedHat-virtlab722/v8.0.0/150-regression.html >> >> The rest of the cases doesn't show any change at all. I can provide more >> data if someone is interested. > > Which commit caused the regression?
Hello Stefan, the same one that caused the improvement on rotational disks: 6d740fb01b9f0f5ea7a82f4d5e458d91940a19ee Lukáš > > Stefan >
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