Re: group scheduler regression since 4.3 (bisect 9d89c257d sched/fair: Rewrite runnable load and utilization average tracking)

From	Christian Borntraeger <borntraeger@de.ibm.com>
Newsgroups	linux.kernel
Subject	Re: group scheduler regression since 4.3 (bisect 9d89c257d sched/fair: Rewrite runnable load and utilization average tracking)
Date	2016-09-26 14:10 +0200
Message-ID	<slCTn-3FS-5@gated-at.bofh.it> (permalink)
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On 09/26/2016 01:53 PM, Peter Zijlstra wrote:
> On Mon, Sep 26, 2016 at 01:42:05PM +0200, Christian Borntraeger wrote:
>> On 09/26/2016 12:56 PM, Peter Zijlstra wrote:
> 
>>> One of the differences in the old and new thing is being addressed by
>>> these patches:
>>>
>>>   https://lkml.kernel.org/r/1473666472-13749-1-git-send-email-vincent.guittot@linaro.org
>>>
>>> Could you see if those patches make a difference? If not, we'll have to
>>> go poke elsewhere ofcourse ;-)
>>
>> Those patches do not apply cleanly on v4.7, linux/master or next/master.
>> Is there a good branch to test these patches?
> 
> They seemed to apply for me on tip/sched/core, I pushed out a branch for
> you that has them on.
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/propagate
> 
> I didn't boot the result though; but they applied without issue.

They applied ok on next from 9/13. Things go even worse.
With this host configuration:

CPU NODE BOOK SOCKET CORE L1d:L1i:L2d:L2i ONLINE CONFIGURED ADDRESS
0   0    0    0      0    0:0:0:0         yes    yes        0
1   0    0    0      0    1:1:1:1         yes    yes        1
2   0    0    0      1    2:2:2:2         yes    yes        2
3   0    0    0      1    3:3:3:3         yes    yes        3
4   0    0    1      2    4:4:4:4         yes    yes        4
5   0    0    1      2    5:5:5:5         yes    yes        5
6   0    0    1      3    6:6:6:6         yes    yes        6
7   0    0    1      3    7:7:7:7         yes    yes        7
8   0    0    1      4    8:8:8:8         yes    yes        8
9   0    0    1      4    9:9:9:9         yes    yes        9
10  0    0    1      5    10:10:10:10     yes    yes        10
11  0    0    1      5    11:11:11:11     yes    yes        11
12  0    0    1      6    12:12:12:12     yes    yes        12
13  0    0    1      6    13:13:13:13     yes    yes        13
14  0    0    1      7    14:14:14:14     yes    yes        14
15  0    0    1      7    15:15:15:15     yes    yes        15

the guest was running either on 0-3 or on 4-15, but never
used the full system. With group scheduling disabled everything was good
again. So looks like that this bug has also some dependency on on the
host topology.

Christian

Thread

group scheduler regression since 4.3 (bisect 9d89c257d sched/fair:  Rewrite runnable load and utilization average tracking) Christian Borntraeger <borntraeger@de.ibm.com> - 2016-09-26 12:50 +0200
  Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Peter Zijlstra <peterz@infradead.org> - 2016-09-26 13:00 +0200
    Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Christian Borntraeger <borntraeger@de.ibm.com> - 2016-09-26 13:50 +0200
      Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Peter Zijlstra <peterz@infradead.org> - 2016-09-26 14:00 +0200
        Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Christian Borntraeger <borntraeger@de.ibm.com> - 2016-09-26 14:10 +0200
          Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Peter Zijlstra <peterz@infradead.org> - 2016-09-26 14:20 +0200
            Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Christian Borntraeger <borntraeger@de.ibm.com> - 2016-09-26 15:00 +0200
            Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Christian Borntraeger <borntraeger@de.ibm.com> - 2016-09-26 16:20 +0200
    Re: group scheduler regression since 4.3 (bisect 9d89c257d  sched/fair: Rewrite runnable load and utilization average tracking) Vincent Guittot <vincent.guittot@linaro.org> - 2016-09-26 14:30 +0200

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