Re: [lkp-robot] [sched, cpumask] 9475ceda45: -6% regression of hackbench.throughput

[Ye Xiaolong <xiaolong.ye@intel.com>]

[-- Attachment #1: Type: text/plain, Size: 3416 bytes --]

On 05/16, Peter Zijlstra wrote:
>On Tue, May 16, 2017 at 09:33:49AM +0800, kernel test robot wrote:
>> 
>> Greeting,
>> 
>> We noticed a -6% regression of hackbench.throughput due to commit:
>> 
>> commit: 9475ceda453545fc55b2ccf30b1fbed0e590fdca ("sched,cpumask: Export for_each_cpu_wrap()")
>> https://git.kernel.org/cgit/linux/kernel/git/peterz/queue.git schd/wip
>> 
>> in testcase: hackbench
>> on test machine: 112 threads Skylake with 64G memory
>
>How many sockets does that have? 112 threads is 56 cores. With a 23 core
>part that gives 2 sockets. But 23 is a very weird number of cores to
>have on a part (also wikipedia doesn't yet list the SKX parts).
>

Hi, ying

The tbox is lkp-skl-sp1, how do I get the socket info for it?

Thanks,
Xiaolong


>> with following parameters:
>> 
>> 	nr_threads: 50%
>> 	mode: threads
>> 	ipc: socket
>> 	cpufreq_governor: performance
>> 
>> test-description: Hackbench is both a benchmark and a stress test for the Linux kernel scheduler.
>> test-url: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/sched/cfs-scheduler/hackbench.c
>
>> Details are as below:
>> -------------------------------------------------------------------------------------------------->
>> 
>> 
>> To reproduce:
>> 
>>         git clone https://github.com/01org/lkp-tests.git
>>         cd lkp-tests
>>         bin/lkp install job.yaml  # job file is attached in this email
>>         bin/lkp run     job.yaml
>> 
>> testcase/path_params/tbox_group/run: hackbench/50%-threads-socket-performance/lkp-skl-sp1
>> 
>
>> 
>>                                 hackbench.throughput
>> 
>>   145000 ++-----------------------------------------------------------------+
>>   140000 *+**.*.*               *. .**.*.*.**.*.**.*.**.*. *.*.**.      .*  |
>>          |       *.*.**.*.**.*.*  *                       *       *.**.*  *.*
>>   135000 ++                                                                 |
>>   130000 ++                         O      OO O OO                          |
>>          |              O OO   OO O  O O O                                  |
>>   125000 ++                  O                                              |
>>   120000 ++                                                                 |
>>   115000 ++                                                                 |
>>          |                                                                  |
>>   110000 ++     O                                                           |
>>   105000 ++                                                                 |
>>          | O       O OO                                                     |
>>   100000 O+ O O  O                                                          |
>>    95000 ++-----------------------------------------------------------------+
>
>
>So what is 'hackbench.throughput' and how do you run it? My hackbench
>only gives a total time, like:
>
>$ perf bench sched messaging -g 50 -l 5000
># Running 'sched/messaging' benchmark:
># 20 sender and receiver processes per group
># 50 groups == 2000 processes run
>
>     Total time: 5.302 [sec]
>
>
>And my numbers are nowhere stable enough to conclusively see a
>regression, but I can maybe see a 2% dip on my IVB-EP.
>
>And I so don't want to dig through your script mess again :/