Re: [LKP] [sched/fair] 070f5e860e: reaim.jobs_per_min -10.5% regression

Xing Zhengjun
2020-06-17T00:30:32Z

On 6/16/2020 2:54 PM, Vincent Guittot wrote:
>
> Hi Xing,
>
> Le mardi 16 juin 2020 à 11:17:16 (+0800), Xing Zhengjun a écrit :
>>
>>
>> On 6/15/2020 4:10 PM, Vincent Guittot wrote:
>>> Hi Xing,
>>>
>>> Le lundi 15 juin 2020 à 15:26:59 (+0800), Xing Zhengjun a écrit :
>>>>
>>>>
>>>> On 6/12/2020 7:06 PM, Hillf Danton wrote:
>>>>>
>>>>> On Fri, 12 Jun 2020 14:36:49 +0800 Xing Zhengjun wrote:
>>>
>
> ...
>
>>>
>>
>> I apply the patch based on v5.7, the test result is as the following:
>
> TBH, I didn't expect that the results would still be bad, so i wonder if the threshold are
> the root problem.
>
> Could you run tests with the patch below that removes condition with runnable_avg ?
> I just want to make sure that those 2 conditions are the root cause.
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index da3e5b54715b..f5774d0af059 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -8210,10 +8210,6 @@ group_has_capacity(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
> if (sgs->sum_nr_running < sgs->group_weight)
> return true;
>
> - if ((sgs->group_capacity * imbalance_pct) <
> - (sgs->group_runnable * 100))
> - return false;
> -
> if ((sgs->group_capacity * 100) >
> (sgs->group_util * imbalance_pct))
> return true;
> @@ -8239,10 +8235,6 @@ group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
> (sgs->group_util * imbalance_pct))
> return true;
>
> - if ((sgs->group_capacity * imbalance_pct) <
> - (sgs->group_runnable * 100))
> - return true;
> -
> return false;
> }
>
>
>
> Thanks.
> Vincent
>

I apply the patch based on v5.7, the test result is as the following:

=========================================================================================
tbox_group/testcase/rootfs/kconfig/compiler/runtime/nr_task/debug-setup/test/cpufreq_governor/ucode:

lkp-ivb-d04/reaim/debian-x86_64-20191114.cgz/x86_64-rhel-7.6/gcc-7/300s/100%/test/five_sec/performance/0x21

commit:
9f68395333ad7f5bfe2f83473fed363d4229f11c
070f5e860ee2bf588c99ef7b4c202451faa48236
v5.7
63a5d0fbb5ec62f5148c251c01e709b8358cd0ee (the test patch)

9f68395333ad7f5b 070f5e860ee2bf588c99ef7b4c2 v5.7
63a5d0fbb5ec62f5148c251c01e
---------------- --------------------------- ---------------------------
---------------------------
%stddev %change %stddev %change
%stddev %change %stddev
\ | \ | \
| \
0.69 -10.3% 0.62 -9.1% 0.62
+1.0% 0.69 reaim.child_systime
0.62 -1.0% 0.61 +0.5% 0.62
-0.1% 0.62 reaim.child_utime
66870 -10.0% 60187 -7.6% 61787
+1.1% 67636 reaim.jobs_per_min
16717 -10.0% 15046 -7.6% 15446
+1.1% 16909 reaim.jobs_per_min_child
97.84 -1.1% 96.75 -0.4% 97.43
+0.3% 98.09 reaim.jti
72000 -10.8% 64216 -8.3% 66000
+0.0% 72000 reaim.max_jobs_per_min
0.36 +10.6% 0.40 +7.8% 0.39
-1.1% 0.36 reaim.parent_time
1.58 ± 2% +71.0% 2.70 ± 2% +26.9% 2.01 ±
2% -11.9% 1.39 ± 4% reaim.std_dev_percent
0.00 ± 5% +110.4% 0.01 ± 3% +48.8% 0.01 ±
7% -27.3% 0.00 ± 15% reaim.std_dev_time
50800 -2.4% 49600 -1.6% 50000
+0.0% 50800 reaim.workload

>>
>> =========================================================================================
>> tbox_group/testcase/rootfs/kconfig/compiler/runtime/nr_task/debug-setup/test/cpufreq_governor/ucode:
>>
>> lkp-ivb-d04/reaim/debian-x86_64-20191114.cgz/x86_64-rhel-7.6/gcc-7/300s/100%/test/five_sec/performance/0x21
>>
>> commit:
>> 9f68395333ad7f5bfe2f83473fed363d4229f11c
>> 070f5e860ee2bf588c99ef7b4c202451faa48236
>> v5.7
>> 3e1643da53f3fc7414cfa3ad2a16ab2a164b7f4d (the test patch)
>>
>> 9f68395333ad7f5b 070f5e860ee2bf588c99ef7b4c2 v5.7
>> 3e1643da53f3fc7414cfa3ad2a1
>> ---------------- --------------------------- ---------------------------
>> ---------------------------
>> %stddev %change %stddev %change %stddev %change
>> %stddev
>> \ | \ | \
>> | \
>> 0.69 -10.3% 0.62 -9.1% 0.62
>> -7.1% 0.64 reaim.child_systime
>> 0.62 -1.0% 0.61 +0.5% 0.62
>> +1.3% 0.63 reaim.child_utime
>> 66870 -10.0% 60187 -7.6% 61787
>> -6.1% 62807 reaim.jobs_per_min
>> 16717 -10.0% 15046 -7.6% 15446
>> -6.1% 15701 reaim.jobs_per_min_child
>> 97.84 -1.1% 96.75 -0.4% 97.43
>> -0.5% 97.34 reaim.jti
>> 72000 -10.8% 64216 -8.3% 66000
>> -5.7% 67885 reaim.max_jobs_per_min
>> 0.36 +10.6% 0.40 +7.8% 0.39
>> +6.9% 0.38 reaim.parent_time
>> 1.58 ± 2% +71.0% 2.70 ± 2% +26.9% 2.01 ± 2%
>> +32.5% 2.09 ± 6% reaim.std_dev_percent
>> 0.00 ± 5% +110.4% 0.01 ± 3% +48.8% 0.01 ± 7%
>> +61.7% 0.01 ± 8% reaim.std_dev_time
>> 50800 -2.4% 49600 -1.6% 50000
>> -1.3% 50133 reaim.workload
>>
>>
>>>>
>>>> =========================================================================================
>>>> tbox_group/testcase/rootfs/kconfig/compiler/runtime/nr_task/debug-setup/test/cpufreq_governor/ucode:
>>>>
>>>> lkp-ivb-d04/reaim/debian-x86_64-20191114.cgz/x86_64-rhel-7.6/gcc-7/300s/100%/test/five_sec/performance/0x21
>>>>
>>>> commit:
>>>> 9f68395333ad7f5bfe2f83473fed363d4229f11c
>>>> 070f5e860ee2bf588c99ef7b4c202451faa48236
>>>> v5.7
>>>> 6b33257768b8dd3982054885ea310871be2cfe0b (Hillf's patch)
>>>>
>>>> 9f68395333ad7f5b 070f5e860ee2bf588c99ef7b4c2 v5.7
>>>> 6b33257768b8dd3982054885ea3
>>>> ---------------- --------------------------- ---------------------------
>>>> ---------------------------
>>>> %stddev %change %stddev %change %stddev %change
>>>> %stddev
>>>> \ | \ | \
>>>> | \
>>>> 0.69 -10.3% 0.62 -9.1% 0.62
>>>> -10.1% 0.62 reaim.child_systime
>>>> 0.62 -1.0% 0.61 +0.5% 0.62
>>>> +0.3% 0.62 reaim.child_utime
>>>> 66870 -10.0% 60187 -7.6% 61787
>>>> -8.3% 61305 reaim.jobs_per_min
>>>> 16717 -10.0% 15046 -7.6% 15446
>>>> -8.3% 15326 reaim.jobs_per_min_child
>>>> 97.84 -1.1% 96.75 -0.4% 97.43
>>>> -0.5% 97.37 reaim.jti
>>>> 72000 -10.8% 64216 -8.3% 66000
>>>> -8.3% 66000 reaim.max_jobs_per_min
>>>> 0.36 +10.6% 0.40 +7.8% 0.39
>>>> +9.4% 0.39 reaim.parent_time
>>>> 1.58 ± 2% +71.0% 2.70 ± 2% +26.9% 2.01 ± 2%
>>>> +33.2% 2.11 reaim.std_dev_percent
>>>> 0.00 ± 5% +110.4% 0.01 ± 3% +48.8% 0.01 ± 7%
>>>> +65.3% 0.01 ± 3% reaim.std_dev_time
>>>> 50800 -2.4% 49600 -1.6% 50000
>>>> -1.8% 49866 reaim.workload
>>>>
>>>>
>>>>
>>>> --
>>>> Zhengjun Xing
>>
>> --
>> Zhengjun Xing

--
Zhengjun Xing