Re: [ata] 0568e61225: stress-ng.copy-file.ops_per_sec -15.0% regression

Oliver Sang
2022-08-16T07:03:58Z

[-- Attachment #1: Type: text/plain, Size: 7849 bytes --]

Hi John,

On Fri, Aug 12, 2022 at 12:13:20PM +0100, John Garry wrote:
> On 12/08/2022 06:01, Oliver Sang wrote:
> > hi, Damien Le Moal,
> >
> > On Tue, Aug 09, 2022 at 07:55:53AM -0700, Damien Le Moal wrote:
> > > On 2022/08/09 2:58, John Garry wrote:
> > > > On 08/08/2022 15:52, Damien Le Moal wrote:
> > > > > On 2022/08/05 1:05, kernel test robot wrote:
> > > > > >
> > > > > >
> > > > > > Greeting,
> > > > > >
> > > > > > FYI, we noticed a -15.0% regression of stress-ng.copy-file.ops_per_sec due to commit:
> > > > > >
> > > > > >
> > > > > > commit: 0568e6122574dcc1aded2979cd0245038efe22b6 ("ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors")
> > > > > > https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
> > > > > >
> > > > > > in testcase: stress-ng
> > > > > > on test machine: 96 threads 2 sockets Ice Lake with 256G memory
> > > > > > with following parameters:
> > > > > >
> > > > > > nr_threads: 10%
> > > > > > disk: 1HDD
> > > > > > testtime: 60s
> > > > > > fs: f2fs
> > > > > > class: filesystem
> > > > > > test: copy-file
> > > > > > cpufreq_governor: performance
> > > > > > ucode: 0xb000280
> > > > >
> > > > > Without knowing what the device adapter is, hard to say where the problem is. I
> > > > > suspect that with the patch applied, we may be ending up with a small default
> > > > > max_sectors value, causing overhead due to more commands than necessary.
> > > > >
> > > > > Will check what I see with my test rig.
> > > >
> > > > As far as I can see, this patch should not make a difference unless the
> > > > ATA shost driver is setting the max_sectors value unnecessarily low.
> > >
> > > That is my hunch too, hence my question about which host driver is being used
> > > for this test... That is not apparent from the problem report.
> >
> > we noticed the commit is already in mainline now, and in our tests, there is
> > still similar regression and also on other platforms.
> > could you guide us how to check "which host driver is being used for this
> > test"? hope to supply some useful information.
> >
>
> For me, a complete kernel log may help.

dmesg.xz is attached. also attached dmesg from parent (4cbfca5f77)

>
> > >
> > > >
> > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > If you fix the issue, kindly add following tag
> > > > > > Reported-by: kernel test robot <oliver.sang@intel.com>
> > > > > >
> > > > > >
> > > > > > Details are as below:
> > > > > > -------------------------------------------------------------------------------------------------->
> > > > > >
> > > > > >
> > > > > > To reproduce:
> > > > > >
> > > > > > git clone https://github.com/intel/lkp-tests.git
> > > > > > cd lkp-tests
> > > > > > sudo bin/lkp install job.yaml # job file is attached in this email
> > > > > > bin/lkp split-job --compatible job.yaml # generate the yaml file for lkp run
> > > > > > sudo bin/lkp run generated-yaml-file
> > > > > >
> > > > > > # if come across any failure that blocks the test,
> > > > > > # please remove ~/.lkp and /lkp dir to run from a clean state.
> > > > > >
> > > > > > =========================================================================================
> > > > > > class/compiler/cpufreq_governor/disk/fs/kconfig/nr_threads/rootfs/tbox_group/test/testcase/testtime/ucode:
> > > > > > filesystem/gcc-11/performance/1HDD/f2fs/x86_64-rhel-8.3/10%/debian-11.1-x86_64-20220510.cgz/lkp-icl-2sp1/copy-file/stress-ng/60s/0xb000280
> > > > > >
> > > > > > commit:
> > > > > > 4cbfca5f77 ("scsi: scsi_transport_sas: cap shost opt_sectors according to DMA optimal limit")
> > > > > > 0568e61225 ("ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors")
> > > > > >
> > > > > > 4cbfca5f7750520f 0568e6122574dcc1aded2979cd0
> > > > > > ---------------- ---------------------------
> > > > > > %stddev %change %stddev
> > > > > > \ | \
> > > > > > 1627 -14.9% 1385 stress-ng.copy-file.ops
> > > > > > 27.01 -15.0% 22.96 stress-ng.copy-file.ops_per_sec
> > > > > > 8935079 -11.9% 7870629 stress-ng.time.file_system_outputs
> > > > > > 14.88 ± 5% -31.8% 10.14 ± 3% stress-ng.time.percent_of_cpu_this_job_got
> > > > > > 50912 -14.7% 43413 vmstat.io.bo
> > > > > > 93.78 +1.4% 95.10 iostat.cpu.idle
> > > > > > 3.89 -31.6% 2.66 iostat.cpu.iowait
> > > > > > 4.01 -1.3 2.74 mpstat.cpu.all.iowait%
> > > > > > 0.23 ± 9% -0.1 0.17 ± 11% mpstat.cpu.all.sys%
> > > > > > 1.66 ± 37% -1.2 0.51 ± 55% perf-profile.calltrace.cycles-pp.f2fs_write_end.generic_perform_write.f2fs_buffered_write_iter.f2fs_file_write_iter.do_iter_readv_writev
> > > > > > 1.66 ± 37% -1.1 0.59 ± 25% perf-profile.children.cycles-pp.f2fs_write_end
> > > > > > 1.51 ± 40% -1.1 0.45 ± 26% perf-profile.children.cycles-pp.f2fs_dirty_data_folio
> > > > > > 1.21 ± 49% -1.0 0.23 ± 33% perf-profile.children.cycles-pp.f2fs_update_dirty_folio
> > > > > > 0.88 ± 56% -0.8 0.04 ±111% perf-profile.children.cycles-pp.native_queued_spin_lock_slowpath
> > > > > > 0.14 ± 26% +0.1 0.25 ± 28% perf-profile.children.cycles-pp.page_cache_ra_unbounded
> > > > > > 0.88 ± 56% -0.8 0.04 ±112% perf-profile.self.cycles-pp.native_queued_spin_lock_slowpath
> > > > > > 3164876 ± 9% -20.2% 2524713 ± 7% perf-stat.i.cache-misses
> > > > > > 4.087e+08 -4.6% 3.899e+08 perf-stat.i.dTLB-loads
> > > > > > 313050 ± 10% -18.4% 255410 ± 6% perf-stat.i.node-loads
> > > > > > 972573 ± 9% -16.4% 812873 ± 6% perf-stat.i.node-stores
> > > > > > 3114748 ± 9% -20.2% 2484807 ± 7% perf-stat.ps.cache-misses
> > > > > > 4.022e+08 -4.6% 3.837e+08 perf-stat.ps.dTLB-loads
> > > > > > 308178 ± 10% -18.4% 251418 ± 6% perf-stat.ps.node-loads
> > > > > > 956996 ± 9% -16.4% 799948 ± 6% perf-stat.ps.node-stores
> > > > > > 358486 -8.3% 328694 proc-vmstat.nr_active_file
> > > > > > 1121620 -11.9% 987816 proc-vmstat.nr_dirtied
> > > > > > 179906 -6.7% 167912 proc-vmstat.nr_dirty
> > > > > > 1151201 -1.7% 1131322 proc-vmstat.nr_file_pages
> > > > > > 100181 +9.9% 110078 ± 2% proc-vmstat.nr_inactive_file
> > > > > > 846362 -14.6% 722471 proc-vmstat.nr_written
> > > > > > 358486 -8.3% 328694 proc-vmstat.nr_zone_active_file
> > > > > > 100181 +9.9% 110078 ± 2% proc-vmstat.nr_zone_inactive_file
> > > > > > 180668 -6.8% 168456 proc-vmstat.nr_zone_write_pending
> > > > > > 556469 -3.5% 536985 proc-vmstat.pgactivate
> > > > > > 3385454 -14.6% 2889953 proc-vmstat.pgpgout
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > Disclaimer:
> > > > > > Results have been estimated based on internal Intel analysis and are provided
> > > > > > for informational purposes only. Any difference in system hardware or software
> > > > > > design or configuration may affect actual performance.
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > >
> > >
> > > --
> > > Damien Le Moal
> > > Western Digital Research
> > .
>

[-- Attachment #2: dmesg.xz --]
[-- Type: application/x-xz, Size: 30176 bytes --]

[-- Attachment #3: dmesg-parent.xz --]
[-- Type: application/x-xz, Size: 30880 bytes --]