Messages in this thread | | | Subject | Re: [LKP] [sched/fair] 070f5e860e: reaim.jobs_per_min -10.5% regression | From | Xing Zhengjun <> | Date | Tue, 16 Jun 2020 11:17:16 +0800 |
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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: > > ... > >>> --- a/kernel/sched/fair.c >>> +++ b/kernel/sched/fair.c >>> @@ -8215,12 +8215,8 @@ group_has_capacity(unsigned int imbalanc >>> 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)) >>> + if ((sgs->group_capacity * 100) > (sgs->group_util * imbalance_pct) && >>> + (sgs->group_capacity * 100) > (sgs->group_runnable * imbalance_pct)) >>> return true; >>> return false; >>> @@ -8240,12 +8236,8 @@ group_is_overloaded(unsigned int imbalan >>> if (sgs->sum_nr_running <= sgs->group_weight) >>> return false; >>> - if ((sgs->group_capacity * 100) < >>> - (sgs->group_util * imbalance_pct)) >>> - return true; >>> - >>> - if ((sgs->group_capacity * imbalance_pct) < >>> - (sgs->group_runnable * 100)) >>> + if ((sgs->group_capacity * 100) < (sgs->group_util * imbalance_pct) || >>> + (sgs->group_capacity * 100) < (sgs->group_runnable * imbalance_pct)) >>> return true; >>> return false; >>> >> >> I apply the patch based on v5.7, the regression still existed. > > Thanks for the test. I don't know if it's relevant or not but the results seem a bit > better with the patch and I'd like to check that it's only a matter of threshold to > fix the problem. > > Could you try the patch below which is quite aggressive but will help to confirm this ? > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 28be1c984a42..3c51d557547b 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -8322,10 +8322,13 @@ static inline int sg_imbalanced(struct sched_group *group) > static inline bool > group_has_capacity(unsigned int imbalance_pct, struct sg_lb_stats *sgs) > { > + unsigned long imb; > + > if (sgs->sum_nr_running < sgs->group_weight) > return true; > > - if ((sgs->group_capacity * imbalance_pct) < > + imb = sgs->sum_nr_running * 100; > + if ((sgs->group_capacity * imb) < > (sgs->group_runnable * 100)) > return false; > > @@ -8347,6 +8350,8 @@ group_has_capacity(unsigned int imbalance_pct, struct sg_lb_stats *sgs) > static inline bool > group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs) > { > + unsigned long imb; > + > if (sgs->sum_nr_running <= sgs->group_weight) > return false; > > @@ -8354,7 +8359,8 @@ 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) < > + imb = sgs->sum_nr_running * 100; > + if ((sgs->group_capacity * imb) < > (sgs->group_runnable * 100)) > return true; > >
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 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
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