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From: Alex Shi <alex.shi@linaro.org>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: Yuanhan Liu <yuanhan.liu@intel.com>,
	"Huang, Ying" <ying.huang@intel.com>,
	lkp@01.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [sched] perf-stat.cpu-migrations changes in dd write test
Date: Wed, 25 Dec 2013 14:32:07 +0800	[thread overview]
Message-ID: <52BA7BE7.6030003@linaro.org> (raw)
In-Reply-To: <20131225035615.GA23802@localhost>

On 12/25/2013 11:56 AM, Fengguang Wu wrote:
> On Wed, Dec 25, 2013 at 11:30:27AM +0800, Alex Shi wrote:
>> On 12/23/2013 01:24 PM, Fengguang Wu wrote:
>>> On Mon, Dec 23, 2013 at 01:19:04PM +0800, Alex Shi wrote:
>>>> 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?
>>>
>>> For the case
>>>
>>>         kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd
>>>
>>> It's a KVM with 4 CPUs, 16G memory. There are 4 virtual disks, on top
>>> of each disk there runs 10 dd tasks.
>>
>> I don't know much of kvm. Where the data get from, VM guest or VM host?
> 
> The data are collected in the VM guest.

do you have similar testing on native linux?
> 
> Thanks,
> Fengguang
> 
>> Looks like any guest cpu usage will be counted as user usage in vmstat.
>> and Does the CS and cpu migration reducing cause dd performance increase?
>>>
>>> Thanks,
>>> Fengguang
>>>
>>>>>
>>>>> 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
>>
>>
>> -- 
>> Thanks
>>     Alex


-- 
Thanks
    Alex

      reply	other threads:[~2013-12-25  6:32 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-22  0:30 [sched] perf-stat.cpu-migrations changes in dd write test fengguang.wu
2013-12-23  5:19 ` Alex Shi
2013-12-23  5:24   ` Fengguang Wu
2013-12-25  3:30     ` Alex Shi
2013-12-25  3:56       ` Fengguang Wu
2013-12-25  6:32         ` Alex Shi [this message]

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