On Mon, Jun 06, 2016 at 10:27:24AM +0800, kernel test robot wrote:
>
> FYI, we noticed a -6.3% regression of unixbench.score due to commit:
>
> commit 5c0a85fad949212b3e059692deecdeed74ae7ec7 ("mm: make faultaround
> produce old ptes")
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>
> in testcase: unixbench
> on test machine: lituya: 16 threads Haswell High-end Desktop (i7-5960X 3.0G)
> with 16G memory
> with following parameters: cpufreq_governor=performance/nr_task=1/test=shell8
>
>
> Details are as below:
> -------------------------------------------------------------------------------------------------->
>
>
> =========================================================================================
> compiler/cpufreq_governor/kconfig/nr_task/rootfs/tbox_group/test/testcase:
>
> gcc-4.9/performance/x86_64-rhel/1/debian-x86_64-2015-02-07.cgz/lituya/shell8/unixbench
>
> commit:
> 4b50bcc7eda4d3cc9e3f2a0aa60e590fedf728c5
> 5c0a85fad949212b3e059692deecdeed74ae7ec7
>
> 4b50bcc7eda4d3cc 5c0a85fad949212b3e059692de
> ---------------- --------------------------
> fail:runs %reproduction fail:runs
> | | |
> 3:4 -75% :4
> kmsg.DHCP/BOOTP:Reply_not_for_us,op[#]xid[#]
> %stddev %change %stddev
> \ | \
> 14321 ± 0% -6.3% 13425 ± 0% unixbench.score
> 1996897 ± 0% -6.1% 1874635 ± 0%
> unixbench.time.involuntary_context_switches
> 1.721e+08 ± 0% -6.2% 1.613e+08 ± 0% unixbench.time.minor_page_faults
> 758.65 ± 0% -3.0% 735.86 ± 0% unixbench.time.system_time
> 387.66 ± 0% +5.4% 408.49 ± 0% unixbench.time.user_time
> 5950278 ± 0% -6.2% 5583456 ± 0%
> unixbench.time.voluntary_context_switches
That's weird.
I don't understand why the change would reduce number or minor faults.
It should stay the same on x86-64. Rise of user_time is puzzling too.
Hm. Is reproducible? Across reboot?
--
Kirill A. Shutemov
