On Wed, Jun 01, 2016 at 01:00:10PM +0800, Huang, Ying wrote:
Peter Zijlstra <peterz(a)infradead.org> writes:
> On Tue, May 31, 2016 at 04:34:36PM +0800, Huang, Ying wrote:
>> Hi, Ingo,
>> Part of the regression has been recovered in v4.7-rc1 from -32.9% to
>> -9.8%. But there is still some regression. Is it possible for fully
>> restore it?
> after much searching on how you guys run hackbench... I figured
> something like:
> perf bench sched messaging -g 20 --thread -l 60000
There is a reproduce file attached in the original report email, its
contents is something like below:
2016-05-15 08:57:02 echo performance >
<snip stupid large output>
2016-05-15 09:06:24 /usr/bin/hackbench -g 24 --threads -l 60000
Hope that will help you for reproduce.
It did not, because I didn't have the exact same machine and its not
apparent how I should modify -- if at all -- the arguments to be
representative when ran on my machine.
> on my IVB-EP (2*10*2) is similar to your IVT thing.
> And running something like:
> for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo
performance > $i ; done
> perf stat --null --repeat 10 -- perf bench sched messaging -g 20 --thread -l 60000
| grep "seconds time elapsed"
> gets me:
> 36.786914089 seconds time elapsed ( +- 0.49% )
> 37.054017355 seconds time elapsed ( +- 1.05% )
> origin/master (v4.7-rc1-ish):
> 34.757435264 seconds time elapsed ( +- 3.34% )
> 35.396252515 seconds time elapsed ( +- 3.38% )
> Which doesn't show a regression between v4.6 and HEAD; in fact it shows
> an improvement.
Yes. For hackbench test, linus/master (v4.7-rc1+) is better than v4.6,
but it is worse than v4.6-rc7. Details is as below.
That kernel was broken.. what your point?