Re: [LKP] [sched/fair] 070f5e860e: reaim.jobs_per_min -10.5% regression
From: Xing Zhengjun
Date: Mon Jun 15 2020 - 03:27:07 EST
On 6/12/2020 7:06 PM, Hillf Danton wrote:
On Fri, 12 Jun 2020 14:36:49 +0800 Xing Zhengjun wrote:
Hi Vincent,
We test the regression still existed in v5.7, do you have time to
look at it? Thanks.
=========================================================================================
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
9f68395333ad7f5b 070f5e860ee2bf588c99ef7b4c2 v5.7
---------------- --------------------------- ---------------------------
%stddev %change %stddev %change %stddev
\ | \ | \
0.69 -10.3% 0.62 -9.1% 0.62 reaim.child_systime
0.62 -1.0% 0.61 +0.5% 0.62 reaim.child_utime
66870 -10.0% 60187 -7.6% 61787 reaim.jobs_per_min
16717 -10.0% 15046 -7.6% 15446 reaim.jobs_per_min_child
97.84 -1.1% 96.75 -0.4% 97.43 reaim.jti
72000 -10.8% 64216 -8.3% 66000 reaim.max_jobs_per_min
0.36 +10.6% 0.40 +7.8% 0.39 reaim.parent_time
1.58 Ä 2% +71.0% 2.70 Ä 2% +26.9% 2.01 Ä 2% reaim.std_dev_percent
0.00 Ä 5% +110.4% 0.01 Ä 3% +48.8% 0.01 Ä 7% reaim.std_dev_time
50800 -2.4% 49600 -1.6% 50000 reaim.workload
On 3/19/2020 10:38 AM, kernel test robot wrote:
Greeting,
FYI, we noticed a -10.5% regression of reaim.jobs_per_min due to commit:
commit: 070f5e860ee2bf588c99ef7b4c202451faa48236 ("sched/fair: Take into account runnable_avg to classify group")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
in testcase: reaim
on test machine: 4 threads Intel(R) Core(TM) i3-3220 CPU @ 3.30GHz with 4G memory
with following parameters:
runtime: 300s
nr_task: 100%
test: five_sec
cpufreq_governor: performance
ucode: 0x21
test-description: REAIM is an updated and improved version of AIM 7 benchmark.
test-url: https://sourceforge.net/projects/re-aim-7/
Hi Xing
After 070f5e860ee2 let's treat runnable the same way as util on
comparing capacity in the assumption that
(125 + 110 + 117) / 3 = 117 accounts for 105 within margin of error
before any other proposal with some more reasons.
thanks
Hillf
--- 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.
=========================================================================================
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 Â 2% +71.0% 2.70 Â 2% +26.9% 2.01 Â
2% +33.2% 2.11 reaim.std_dev_percent
0.00 Â 5% +110.4% 0.01 Â 3% +48.8% 0.01 Â
7% +65.3% 0.01 Â 3% reaim.std_dev_time
50800 -2.4% 49600 -1.6% 50000
-1.8% 49866 reaim.workload
--
Zhengjun Xing