Re: [LKP] [lkp] [f2fs] ec795418c4: fsmark.files_per_sec -36.3% regression

[Jaegeuk Kim]

On Mon, Sep 26, 2016 at 02:26:06PM +0800, Huang, Ying wrote:
> Hi, Jaegeuk,
> 
> "Huang, Ying" <ying.huang@xxxxxxxxx> writes:
> 
> > Jaegeuk Kim <jaegeuk@xxxxxxxxxx> writes:
> >
> >> Hello,
> >>
> >> On Sat, Aug 27, 2016 at 10:13:34AM +0800, Fengguang Wu wrote:
> >>> Hi Jaegeuk,
> >>> 
> >>> > > >> > - [lkp] [f2fs] b93f771286: aim7.jobs-per-min -81.2% regression
> >>> > > >> >
> >>> > > >> > The disk is 4 12G ram disk, and setup RAID0 on them via mdadm.  The
> >>> > > >> > steps for aim7 is,
> >>> > > >> >
> >>> > > >> > cat > workfile <<EOF
> >>> > > >> > FILESIZE: 1M
> >>> > > >> > POOLSIZE: 10M
> >>> > > >> > 10 sync_disk_rw
> >>> > > >> > EOF
> >>> > > >> >
> >>> > > >> > (
> >>> > > >> >     echo $HOSTNAME
> >>> > > >> >     echo sync_disk_rw
> >>> > > >> >
> >>> > > >> >     echo 1
> >>> > > >> >     echo 600
> >>> > > >> >     echo 2
> >>> > > >> >     echo 600
> >>> > > >> >     echo 1
> >>> > > >> > ) | ./multitask -t &
> >>> > > >>
> >>> > > >> Any update on these 2 regressions?  Is the information is enough for you
> >>> > > >> to reproduce?
> >>> > > >
> >>> > > > Sorry, I've had no time to dig this due to business travel now.
> >>> > > > I'll check that when back to US.
> >>> > > 
> >>> > > Any update?
> >>> > 
> >>> > Sorry, how can I get multitask binary?
> >>> 
> >>> It's part of aim7, which can be downloaded here:
> >>> 
> >>> http://nchc.dl.sourceforge.net/project/aimbench/aim-suite7/Initial%20release/s7110.tar.Z
> >>
> >> Thank you for the codes.
> >>
> >> I've run this workload on the latest f2fs and compared performance having
> >> without the reported patch. (1TB nvme SSD, 16 cores, 16GB DRAM)
> >> Interestingly, I could find slight performance improvement rather than
> >> regression. :(
> >> Not sure how to reproduce this.
> >
> > I think the difference lies on disk used.  The ramdisk is used in the
> > original test, but it appears that your memory is too small to setup the
> > RAM disk for test.  So it may be impossible for you to reproduce the
> > test unless you can find more memory :)
> >
> > But we can help you to root cause the issue.  What additional data do
> > you want?  perf-profile data before and after the patch?
> 
> Any update to this regression?

Sorry, no. But meanwhile, I've purchased more DRAMs. :)
Now I'm with 128GB DRAM. I can configure 64GB as pmem.
Is it worth to try the test again?

Thanks,

> 
> Best Regards,
> Huang, Ying