Re: [sched] perf-stat.cpu-migrations changes in dd write test

Alex Shi
2013-12-23T05:19:16Z

On 12/22/2013 08:30 AM, fengguang.wu@intel.com wrote:
> Alex,
>
> We noticed some perf-stat.cpu-migrations changes by your commit

Thanks for your wonder testing, Fengguang!
How many CPU in your system and how many dd task running?

>
> 6eb8b571283e64e96ca1a91aad085f9e08f857f0 is the first bad commit
> commit 6eb8b571283e64e96ca1a91aad085f9e08f857f0
> Author: Alex Shi <alex.shi@linaro.org>
> Date: Tue Nov 19 20:29:51 2013 +0800
>
> sched: remove rq->cpu_load[load_idx] array
>
> Since load_idx effect removed in load balance, we don't need the
> load_idx decays in scheduler. that will save some process in sched_tick
> and others places.
>
> Signed-off-by: Alex Shi <alex.shi@linaro.org>
>
>
> Here are the changed stats comparing to its parent commit:
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 37779 ~40% +115.2% 81288 ~50% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 37779 +115.2% 81288 TOTAL proc-vmstat.pgscan_direct_normal
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: proc-vmstat.pgscan_direct_normal
>
> 160000 ++----------------------------------------------------------------+
> | |
> 140000 ++ O
> | |
> 120000 ++ |
> | O |
> 100000 ++ |
> | |
> 80000 ++ O |
> | ..*
> 60000 ++ .... |
> | .... |
> 40000 *+............... O .... |
> O *............... ........*. |
> 20000 ++-------------------------------*--------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 121579 ~ 6% -50.8% 59852 ~13% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 121579 -50.8% 59852 TOTAL softirqs.SCHED
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: softirqs.SCHED
>
> 140000 ++----------------------------------------------------------------+
> 130000 ++ ....*........... ....*....... |
> | ........ .... ........ ...... |
> 120000 *+... *.... ..|
> 110000 ++ *
> | |
> 100000 ++ |
> 90000 ++ |
> 80000 ++ |
> | |
> 70000 ++ O O |
> 60000 ++ O |
> | O
> 50000 O+ |
> 40000 ++----------------------------------------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 5636 ~ 4% -22.1% 4392 ~17% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 5636 -22.1% 4392 TOTAL proc-vmstat.nr_tlb_remote_flush
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: proc-vmstat.nr_tlb_remote_flush
>
> 6500 ++------------------------------------------------------------------+
> | |
> 6000 ++ ........*............ |
> *........ .... |
> 5500 ++ O *................*................|
> | *
> 5000 ++ O |
> | |
> 4500 ++ O |
> | |
> 4000 ++ |
> | O
> 3500 O+ |
> | |
> 3000 ++------------------------------------------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 5679 ~ 4% -21.9% 4437 ~17% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 5679 -21.9% 4437 TOTAL proc-vmstat.nr_tlb_remote_flush_received
>
>
>
> 6500 ++------------------------------------------------------------------+
> | |
> 6000 ++ ........*........ |
> *........ ...... |
> | .. ........*................|
> 5500 ++ O *........ *
> | |
> 5000 ++ O |
> | |
> 4500 ++ O |
> | |
> | |
> 4000 ++ |
> | O
> 3500 O+------------------------------------------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 167 ~11% +19.4% 200 ~ 4% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 167 +19.4% 200 TOTAL uptime.idle
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: uptime.idle
>
> 220 ++-------------------------------------------------------------------+
> | O
> 210 ++ |
> 200 O+ O |
> | ..*..... O |
> 190 ++ .... O ... |
> 180 ++ .... .... |
> | .... .... |
> 170 *+. . .*
> 160 ++ *...... .... |
> | .... ... |
> 150 ++ .... ... |
> 140 ++ .. .... |
> | *. |
> 130 ++-------------------------------------------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 154781 ~ 5% -66.8% 51449 ~ 8% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 154781 -66.8% 51449 TOTAL perf-stat.cpu-migrations
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: perf-stat.cpu-migrations
>
> 180000 ++----------------------------------------------------------------+
> | ....*........... |
> 160000 ++ ........ .... ........*...............|
> *.... *........ *
> 140000 ++ |
> | |
> 120000 ++ |
> | |
> 100000 ++ |
> | |
> 80000 ++ |
> | |
> 60000 ++ O |
> | O O O
> 40000 O+----------------------------------------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 1943 ~ 3% -7.8% 1792 ~ 4% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 1943 -7.8% 1792 TOTAL vmstat.system.cs
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: vmstat.system.cs
>
> 2050 ++------------------------------------------------------------------+
> | ........*................*..... |
> 2000 ++ .*........ ... |
> 1950 ++ .... ... |
> | ... .... |
> 1900 ++ ... .|
> 1850 ++.... O O *
> *. |
> 1800 ++ O O
> 1750 ++ |
> | |
> 1700 ++ |
> 1650 O+ |
> | |
> 1600 ++------------------------------------------------------------------+
>
>
> 1de157d718f6494 6eb8b571283e64e96ca1
> --------------- -------------------------
> 1216177 ~ 3% -9.4% 1101605 ~ 7% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
> 1216177 -9.4% 1101605 TOTAL perf-stat.context-switches
>
> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: perf-stat.context-switches
>
> 1.3e+06 ++--------------------------------------------------------------+
> | ..*............... |
> 1.25e+06 ++ ...... *...............*....... |
> | ..... ...... |
> 1.2e+06 *+. O ..|
> 1.15e+06 ++ O *
> | O |
> 1.1e+06 ++ |
> | O
> 1.05e+06 ++ |
> 1e+06 ++ |
> | |
> 950000 O+ |
> | |
> 900000 ++--------------------------------------------------------------+
>
>

--
Thanks
Alex