Dne 26. 05. 23 v 12:56 Stefan Hajnoczi napsal(a): > On Fri, 26 May 2023 at 04:07, Lukáš Doktor <ldok...@redhat.com> wrote: >> >> Dne 25. 05. 23 v 17:21 Stefan Hajnoczi napsal(a): >>> On Thu, 25 May 2023 at 06:18, Lukáš Doktor <ldok...@redhat.com> 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.
Regards,
Lukáš
> Thanks!
>
> Stefan
>
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