On Fri, Aug 16 2019, Jinpu Wang wrote: > On Wed, Aug 7, 2019 at 2:35 PM Jinpu Wang <jinpu.w...@cloud.ionos.com> wrote: >> >> On Wed, Aug 7, 2019 at 8:36 AM Jinpu Wang <jinpu.w...@cloud.ionos.com> wrote: >> > >> > On Wed, Aug 7, 2019 at 1:40 AM NeilBrown <ne...@suse.com> wrote: >> > > >> > > On Tue, Aug 06 2019, Jinpu Wang wrote: >> > > >> > > > On Tue, Aug 6, 2019 at 9:54 AM Jinpu Wang <jinpu.w...@cloud.ionos.com> >> > > > wrote: >> > > >> >> > > >> On Tue, Aug 6, 2019 at 1:46 AM NeilBrown <ne...@suse.com> wrote: >> > > >> > >> > > >> > On Mon, Aug 05 2019, Jinpu Wang wrote: >> > > >> > >> > > >> > > Hi Neil, >> > > >> > > >> > > >> > > For the md higher write IO latency problem, I bisected it to >> > > >> > > these commits: >> > > >> > > >> > > >> > > 4ad23a97 MD: use per-cpu counter for writes_pending >> > > >> > > 210f7cd percpu-refcount: support synchronous switch to atomic >> > > >> > > mode. >> > > >> > > >> > > >> > > Do you maybe have an idea? How can we fix it? >> > > >> > >> > > >> > Hmmm.... not sure. >> > > >> Hi Neil, >> > > >> >> > > >> Thanks for reply, detailed result in line. >> > > >> > > Thanks for the extra testing. >> > > ... >> > > > [ 105.133299] md md0 in_sync is 0, sb_flags 2, recovery 3, external >> > > > 0, safemode 0, recovery_cp 524288 >> > > ... >> > > >> > > ahh - the resync was still happening. That explains why set_in_sync() >> > > is being called so often. If you wait for sync to complete (or create >> > > the array with --assume-clean) you should see more normal behaviour. >> > I've updated my tests accordingly, thanks for the hint. >> > > >> > > This patch should fix it. I think we can do better but it would be more >> > > complex so no suitable for backports to -stable. >> > > >> > > Once you confirm it works, I'll send it upstream with a >> > > Reported-and-Tested-by from you. >> > > >> > > Thanks, >> > > NeilBrown >> > >> > Thanks a lot, Neil, my quick test show, yes, it fixed the problem for me. >> > >> > I will run more tests to be sure, will report back the test result. >> Hi Neil, >> >> I've run our regression tests with your patch, everything works fine >> as expected. >> >> So Reported-and-Tested-by: Jack Wang <jinpu.w...@cloud.ionos.com> >> >> Thank you for your quick fix. >> >> The patch should go to stable 4.12+ > > Hi Neil, > > I hope you're doing well, just a soft ping? do you need further > testing from my side?
Thanks for the reminder. I've sent out the patch now. NeilBrown > > Please let me know how can we move the fix forward. > > Thanks, > Jack Wang
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