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

[Jaegeuk Kim]

On Tue, Sep 27, 2016 at 08:50:02AM +0800, Huang, Ying wrote:
> Jaegeuk Kim <jaegeuk@xxxxxxxxxx> writes:
> 
> > 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?
> 
> I think you are the decision maker for this.  You can judge whether the
> test is reasonable.  And we can adjust our test accordingly.
> 
> BTW: For this test, we use brd ram disk and raid to test.

Okay, let me try this again.
Thanks,

> 
> Best Regards,
> Huang, Ying