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From: Matt Fleming <matt@codeblueprint.co.uk>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Wanpeng Li <kernellwp@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Mike Galbraith <umgwanakikbuti@gmail.com>,
	Yuyang Du <yuyang.du@intel.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>
Subject: Re: [PATCH] sched/fair: Do not decay new task load on first enqueue
Date: Tue, 18 Oct 2016 11:29:37 +0100	[thread overview]
Message-ID: <20161018102937.GI16071@codeblueprint.co.uk> (raw)
In-Reply-To: <20161011102453.GA16071@codeblueprint.co.uk>

On Tue, 11 Oct, at 11:24:53AM, Matt Fleming wrote:
> 
> That's a lot more costly cross-DIE migrations. I think this patch is
> along the right lines, but there's something fishy happening on this
> box.

I wasn't really able to track down why this machine regressed, and the
patch shows enough improvement for other boxes that I think it's worth
sticking in tip/sched/core.

I saw a number of double digit gains for hackbench with this patch.
Here's a 4-cpu box that shows improvements in arithmetic mean and some
nice improvements to the stddev,

hackbench-process-pipes
                            4.8.0                 4.8.0
                          vanilla  find-idle-group-v1r1
Amean    1       3.2580 (  0.00%)      3.0607 (  6.06%)
Amean    3       8.0387 (  0.00%)      8.2027 ( -2.04%)
Amean    5      12.0507 (  0.00%)     12.1703 ( -0.99%)
Amean    7      16.0027 (  0.00%)     16.4567 ( -2.84%)
Amean    12     26.9030 (  0.00%)     21.7767 ( 19.05%)
Amean    16     33.4127 (  0.00%)     28.9877 ( 13.24%)
Stddev   1       0.1383 (  0.00%)      0.1787 (-29.22%)
Stddev   3       0.1297 (  0.00%)      0.1677 (-29.29%)
Stddev   5       0.5495 (  0.00%)      0.4549 ( 17.22%)
Stddev   7       0.7401 (  0.00%)      0.6161 ( 16.75%)
Stddev   12      2.3187 (  0.00%)      0.7102 ( 69.37%)
Stddev   16      4.0734 (  0.00%)      2.9364 ( 27.91%)

And a 60-cpu box with similar improvements,

hackbench-process-sockets
                             4.8.0                 4.8.0
                           vanilla  find-idle-group-v1r1
Amean    1       32.8810 (  0.00%)      2.0590 ( 93.74%)
Amean    4       34.8663 (  0.00%)      3.3177 ( 90.48%)
Amean    7       34.1243 (  0.00%)      4.3323 ( 87.30%)
Amean    12      36.8373 (  0.00%)      5.3650 ( 85.44%)
Amean    21      29.0333 (  0.00%)      6.0280 ( 79.24%)
Amean    30      27.2807 (  0.00%)      7.2653 ( 73.37%)
Amean    48      23.2453 (  0.00%)      9.9810 ( 57.06%)
Amean    79      29.6660 (  0.00%)     16.6680 ( 43.81%)
Amean    110     41.3680 (  0.00%)     23.1787 ( 43.97%)
Amean    141     45.3720 (  0.00%)     29.4130 ( 35.17%)
Amean    172     45.6403 (  0.00%)     34.3783 ( 24.68%)
Amean    203     47.6120 (  0.00%)     40.0063 ( 15.97%)
Amean    234     50.1703 (  0.00%)     43.4503 ( 13.39%)
Amean    240     50.1110 (  0.00%)     44.4660 ( 11.26%)
Stddev   1        0.9714 (  0.00%)      0.6617 ( 31.88%)
Stddev   4        0.4459 (  0.00%)      0.2943 ( 34.01%)
Stddev   7        0.3091 (  0.00%)      0.2722 ( 11.94%)
Stddev   12       0.4603 (  0.00%)      0.1424 ( 69.05%)
Stddev   21       1.3647 (  0.00%)      0.1566 ( 88.52%)
Stddev   30       4.1277 (  0.00%)      0.0481 ( 98.84%)
Stddev   48       1.3689 (  0.00%)      0.4968 ( 63.71%)
Stddev   79       2.0772 (  0.00%)      0.5309 ( 74.44%)
Stddev   110      4.5655 (  0.00%)      0.1846 ( 95.96%)
Stddev   141      4.2637 (  0.00%)      0.6675 ( 84.34%)
Stddev   172      1.5741 (  0.00%)      1.0242 ( 34.93%)
Stddev   203      1.0973 (  0.00%)      1.4043 (-27.98%)
Stddev   234      2.2048 (  0.00%)      0.8709 ( 60.50%)
Stddev   240      1.2849 (  0.00%)      0.2688 ( 79.08%)

  parent reply	other threads:[~2016-10-18 10:29 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-23 11:58 [PATCH] sched/fair: Do not decay new task load on first enqueue Matt Fleming
2016-09-23 14:30 ` Vincent Guittot
2016-09-27 13:48   ` Dietmar Eggemann
2016-09-27 19:24     ` Matt Fleming
2016-09-27 19:21   ` Matt Fleming
2016-09-28 10:14 ` Peter Zijlstra
2016-09-28 11:06   ` Dietmar Eggemann
2016-09-28 11:19     ` Peter Zijlstra
2016-09-28 11:31       ` Dietmar Eggemann
2016-09-28 11:46         ` Vincent Guittot
2016-09-28 12:00           ` Vincent Guittot
2016-10-04 21:25             ` Matt Fleming
2016-10-04 20:16           ` Matt Fleming
2016-09-28 12:27         ` Vincent Guittot
2016-09-28 13:13           ` Vincent Guittot
2016-09-29 16:15             ` Dietmar Eggemann
2016-10-03 13:05               ` Vincent Guittot
2016-09-28 17:59       ` Dietmar Eggemann
2016-09-28 19:37   ` Matt Fleming
2016-09-30 20:30     ` Matt Fleming
2016-10-09  3:39     ` Wanpeng Li
2016-10-10 10:01       ` Matt Fleming
2016-10-10 10:09         ` Wanpeng Li
2016-10-11 10:27           ` Matt Fleming
2016-10-10 12:29         ` Vincent Guittot
2016-10-10 13:54           ` Dietmar Eggemann
2016-10-10 18:29             ` Vincent Guittot
2016-10-11  9:44               ` Dietmar Eggemann
2016-10-11 10:39                 ` Matt Fleming
2016-10-18 10:11                   ` Matt Fleming
2016-10-10 17:34           ` Vincent Guittot
2016-10-11 10:24             ` Matt Fleming
2016-10-11 13:14               ` Vincent Guittot
2016-10-11 18:57                 ` Matt Fleming
2016-10-12  7:41                   ` Vincent Guittot
2016-10-18 11:09                     ` Peter Zijlstra
2016-10-18 15:19                       ` Vincent Guittot
2016-10-18 10:29               ` Matt Fleming [this message]
2016-10-18 11:10                 ` Peter Zijlstra
2016-10-18 11:29                   ` Matt Fleming
2016-10-18 12:15                     ` Peter Zijlstra
2016-10-19  6:38                       ` Vincent Guittot
2016-10-19  9:53                         ` Peter Zijlstra
2016-11-09 16:53                           ` Vincent Guittot
2016-10-04 20:11   ` Matt Fleming
2016-10-09  5:57 ` [lkp] [sched/fair] f54c5d4e28: hackbench.throughput 10.6% improvement kernel test robot

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