Re: [tracing] 939c7a4f04f: -46.4% cpuidle.C3-IVT.time

From: Yoshihiro YUNOMAE
Date: Thu Jun 19 2014 - 02:05:36 EST


Hi Jet,

Thank you for your report.
I have some questions for your test.

1. Did you enable ftrace?
This patch added a feature for ftrace. If you disabled ftrace in
this test, my patch will not affect the system. Moreover, in my patch,
arrays for saved_cmdlines were just changed from using static global
variables to using kmalloc() on default setting. So, even if you enabled
ftrace, this patch will not induce a big problem, I think.

2. How did you test it and what does the result mean?
Please tell me the workload, how to calculate the score,
system settings, etc...

Thanks,
Yoshihiro YUNOMAE

(2014/06/18 12:15), Jet Chen wrote:
Hi Yoshihiro,

FYI, we noticed the below changes on

commit 939c7a4f04fcd2162109744e8bf88194948a6e65 ("tracing: Introduce
saved_cmdlines_size file")

test case: brickland3/aim7/3000-brk_test

beba4bb096201ce 939c7a4f04fcd2162109744e8
--------------- -------------------------
352643 ~40% -46.4% 189136 ~15% TOTAL cpuidle.C3-IVT.time
750 ~ 2% -13.3% 650 ~ 2% TOTAL vmstat.procs.b
362016 ~ 3% -6.0% 340296 ~ 3% TOTAL
proc-vmstat.pgmigrate_success
362016 ~ 3% -6.0% 340296 ~ 3% TOTAL
proc-vmstat.numa_pages_migrated
1642328 ~ 3% +13.3% 1860721 ~ 2% TOTAL softirqs.RCU
2278829 ~ 2% -14.0% 1959647 ~ 2% TOTAL
time.voluntary_context_switches
207 ~ 0% -10.4% 185 ~ 0% TOTAL time.user_time
~ 0% +8.5% ~ 0% TOTAL turbostat.RAM_W
4418246 ~ 3% -6.4% 4136447 ~ 1% TOTAL time.minor_page_faults
~ 0% +3.4% ~ 0% TOTAL turbostat.Cor_W
~ 0% +3.0% ~ 0% TOTAL turbostat.Pkg_W
11354889 ~ 0% +2.0% 11579897 ~ 0% TOTAL
time.involuntary_context_switches

Legend:
~XX% - stddev percent
[+-]XX% - change percent


time.voluntary_context_switches

2.4e+06
++---------------------------------------------------*------------+
*.. *.. ..
.. |
2.3e+06 ++ .*.. *.. ..
* |
| *..*. . .*.. .. * *.. +
*.. *..*
| *. * . .*..*.. +
.. |
2.2e+06 ++ *..*. *
* |

| |
2.1e+06
++ |

| |
2e+06 O+ O O
O |
| O O O
O |
| O O O O
O |
1.9e+06 ++ O O O
O |
| O O
O |
1.8e+06
++----------------------------------------------------------------+


turbostat.Pkg_W

++--------------------------------------------------------------------+
O+ O O O O O |
| O O O O O O O O O O O O |
++ O O |
++ |
++ |
++ |
| |
++ |
++ |
++ *.. .*.. |
*+.*... .. *...*. *...*..*..*...*..*.. ..*.. *...*..*..*...*..*
| * *. .. |
++ * |
++--------------------------------------------------------------------+


turbostat.Cor_W

++--------------------------------------------------------------------+
O+ O O O O O O O O O |
| O O O O O O O O O O |
++ |
++ |
| |
++ |
++ |
++ |
| |
++ *.. |
*+.*... .. *...*..*..*...*..*..*...*..*.. ..*.. *... .*..*...*..*
| * *. .. *. |
++ * |
++--------------------------------------------------------------------+


turbostat.RAM_W

++---------------------------------------------------------------------+
| O O O O O O O O |
O+ O O O O O O O O O O |
| O |
++ |
| |
++ |
| |
++ |
| * |
++ .. + *.. |
| .*..* + *.. *.. + ..*..*.. .*... |
++ .. + .. .. . + *. *...*. *..*
*..*...*..* * *...* * |
++---------------------------------------------------------------------+


[*] bisect-good sample
[O] bisect-bad sample


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.

Thanks,
Jet



--
Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae.ez@xxxxxxxxxxx


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/