Re: [lkp-robot] [scsi] 5c279bd9e4: blogbench.read_score -10.0% regression

[Ye Xiaolong]

Hi, Ming Lei

On 07/06, Ming Lei wrote:
>Hi Xiaolong,
>
>On Mon, Jul 3, 2017 at 10:57 AM, kernel test robot
><xiaolong.ye@xxxxxxxxx> wrote:
>>
>> Greeting,
>>
>> FYI, we noticed a -10.0% regression of blogbench.read_score due to commit:
>
>Looks like related with mq scheduler, could you test the following patch to see
>if your issue can be fixed?
>
>https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?h=for-linus&id=32825c45ff8f4cce937ab85b030dc693ceb1aa0a
>

Here is the comparison of commit 5c279bd9e4 and 32825c45, it does help recover
performance back.

$ compare -at 5c279bd9e40624f4ab6e688671026d6005b066fa 32825c45ff8f4cce937ab85b030dc693ceb1aa0a
tests: 1
testcase/path_params/tbox_group/run: blogbench/1SSD-ext4-performance/lkp-bdw-de1

5c279bd9e40624f4  32825c45ff8f4cce937ab85b03  
----------------  --------------------------  
         %stddev      change         %stddev
             \          |                \  
    262860              36%     358558        blogbench.read_score
      9913 ±  4%       -33%       6654        blogbench.write_score
  86266452              31%  1.129e+08        blogbench.time.file_system_inputs
     29.89              22%      36.46        blogbench.time.user_time
       214              13%        242        blogbench.time.percent_of_cpu_this_job_got
       620              12%        696        blogbench.time.system_time
  1.11e+08             -29%   79019314        blogbench.time.file_system_outputs
    439016             -69%     135286        blogbench.time.involuntary_context_switches
      0.64              22%       0.78        mpstat.cpu.usr%
      7.02 ±  4%       -47%       3.72        mpstat.cpu.idle%
    237216            1344%    3425183        softirqs.RCU
    430504             376%    2048486        softirqs.TIMER
    188376             211%     586308        softirqs.SCHED
    306478 ± 32%       -99%       4150 ± 36%  softirqs.NET_RX
  86266452              31%  1.129e+08        time.file_system_inputs
     29.89              22%      36.46        time.user_time

Thanks,
Xiaolong

>
>Thanks,
>Ming Lei