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

From: Ye Xiaolong
Date: Wed Jul 05 2017 - 22:55:12 EST


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