On 10/25, Thomas Gleixner wrote:
>On Tue, 25 Oct 2016, kernel test robot wrote:
>> FYI, we noticed a -2.3% regression of will-it-scale.per_thread_ops due to
>> commit:
>>
>> commit 71854cb812ec23bfe5f63d52217e6b9e6cb901f5 ("x86/platform/UV: Fix
>> support for EFI_OLD_MEMMAP after BIOS callback updates")
>> https://github.com/0day-ci/linux
>> Alex-Thorlton/x86-platform-UV-Fix-support-for-EFI_OLD_MEMMAP-after-BIOS-callback-updates/20161020-095215
>>
>> in testcase: will-it-scale
>> on test machine: 12 threads Intel(R) Core(TM) i7 CPU X 980 @ 3.33GHz with 6G
>> memory
>
>This is completely bogus. That patch does not even affect anything outside
>of the SGI UV platform. And on your i7 system uv_bios_call() is definitely
>not invoked.
Yes, this is weird, the per_thread_ops change is small and should be run
to run variation, the actual significant change is will-it-scale.time.user_time
-27% decrease, but the patch seems not relevant, we can't interpret it. :(
We've tried to queue the jobs (4 times) for
71854cb812ec23bfe5f63d52217e6b9e6cb901f5 and v4.9-rc1
with new kconfig (added CONFIG_DEBUG_INFO_REDUCED), and result shows
user_time change is quite stable.
=========================================================================================
compiler/cpufreq_governor/kconfig/rootfs/tbox_group/test/testcase:
gcc-6/performance/x86_64-rhel-7.2+CONFIG_DEBUG_INFO_REDUCED/debian-x86_64-2016-08-31.cgz/wsm/read2/will-it-scale
commit:
v4.9-rc1
71854cb812ec23bfe5f63d52217e6b9e6cb901f5
v4.9-rc1 71854cb812ec23bfe5f63d5221
---------------- --------------------------
%stddev %change %stddev
\ | \
1670068 ± 0% -3.8% 1606650 ± 1% will-it-scale.per_thread_ops
9749 ± 2% +1328.0% 139222 ±105%
will-it-scale.time.involuntary_context_switches
981.29 ± 0% +2.2% 1002 ± 0% will-it-scale.time.system_time
81.78 ± 0% -26.9% 59.74 ± 0% will-it-scale.time.user_time
32894 ± 0% -3.1% 31863 ± 2% vmstat.system.cs
9749 ± 2% +1328.0% 139222 ±105% time.involuntary_context_switches
380917 ± 2% -10.2% 341970 ± 3% sched_debug.cpu.avg_idle.avg
89166 ± 33% -73.4% 23731 ± 29% sched_debug.cpu.avg_idle.min
16.38 ± 10% -32.3% 11.08 ± 18%
sched_debug.cpu.nr_uninterruptible.max
0.29 ± 1% +32.6% 0.38 ± 1% perf-stat.branch-miss-rate%
2.897e+09 ± 1% +33.5% 3.867e+09 ± 2% perf-stat.branch-misses
10084878 ± 0% -3.2% 9761852 ± 2% perf-stat.context-switches
0.00 ± 7% -9.3% 0.00 ± 1% perf-stat.dTLB-store-miss-rate%
33489012 ± 7% -9.2% 30416429 ± 1% perf-stat.dTLB-store-misses
Thanks,
Xiaolong
>
>I appreciate your effort, but posting such obviously bogus results does not
>make people more confident in your testing efforts.
>
>Thanks,
>
> tglx
