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Message-ID: <20171011013242.GL11865@yexl-desktop>
Date:   Wed, 11 Oct 2017 09:32:42 +0800
From:   kernel test robot <xiaolong.ye@...el.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Ingo Molnar <mingo@...nel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>,
        "H. Peter Anvin" <hpa@...or.com>, tipbuild@...or.com, lkp@...org
Subject: [lkp-robot] [sched/fair]  c7b5021681:  hackbench.throughput -9.0%
 regression
Greeting,
FYI, we noticed a -9.0% regression of hackbench.throughput due to commit:
commit: c7b50216818ef3dca14a52e3499750fbad2d9691 ("sched/fair: Remove se->load.weight from se->avg.load_sum")
https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git sched/core
in testcase: hackbench
on test machine: 8 threads Intel(R) Atom(TM) CPU C2750 @ 2.40GHz with 16G memory
with following parameters:
	nr_threads: 1600%
	mode: process
	ipc: socket
	cpufreq_governor: performance
test-description: Hackbench is both a benchmark and a stress test for the Linux kernel scheduler.
test-url: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/sched/cfs-scheduler/hackbench.c
Details are as below:
-------------------------------------------------------------------------------------------------->
To reproduce:
        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp install job.yaml  # job file is attached in this email
        bin/lkp run     job.yaml
testcase/path_params/tbox_group/run: hackbench/1600%-process-socket-performance/lkp-avoton3
3d4b60d3e3dde6ea  c7b50216818ef3dca14a52e349  
----------------  --------------------------  
     22302              -9%      20297        hackbench.throughput
  45912536              40%   64214329        hackbench.time.voluntary_context_switches
   2743841 ±  3%       -11%    2442816        hackbench.time.minor_page_faults
   5009676             213%   15682381 ±  3%  hackbench.time.involuntary_context_switches
     26970             103%      54756        vmstat.system.in
     82806              59%     131735        vmstat.system.cs
     12.50               4%      13.02        boot-time.dhcp
   1491351              10%    1645037        perf-stat.cpu-migrations
      1.20              55%       1.86        perf-stat.branch-miss-rate%
 1.229e+10 ±  3%        43%  1.758e+10        perf-stat.branch-misses
 5.659e+10 ±  3%        -7%  5.263e+10        perf-stat.cache-misses
     28.81              -9%      26.08        perf-stat.cache-miss-rate%
      2.19               7%       2.34        perf-stat.cpi
      0.21              32%       0.28        perf-stat.iTLB-load-miss-rate%
  51611348              56%   80586388        perf-stat.context-switches
 1.211e+10              22%  1.474e+10        perf-stat.iTLB-load-misses
 1.025e+12 ±  3%        -8%  9.468e+11        perf-stat.branch-instructions
 5.746e+12 ±  3%        -8%  5.293e+12        perf-stat.instructions
 5.744e+12 ±  3%        -8%  5.293e+12        perf-stat.iTLB-loads
       474             -24%        359        perf-stat.instructions-per-iTLB-miss
      0.46              -6%       0.43        perf-stat.ipc
   2874382 ±  3%       -10%    2572671        perf-stat.minor-faults
   2874383 ±  3%       -10%    2572671        perf-stat.page-faults
                                                                                
                      hackbench.time.involuntary_context_switches               
                                                                                
    3e+07 +-+---------------------------------------------------------------+   
          |                O   O     O                                      |   
  2.5e+07 +-+OO O O  O OOO  O O O OO  OO O                                  |   
          OO     O  O                                                       |   
          |                                                                 |   
    2e+07 +-+                                                               |   
          |                                  O                              |   
  1.5e+07 +-+                             O O  OOO                          |   
          |                                                                 |   
    1e+07 +-+                                                               |   
          |                                                                 |   
          |    .+     .+ +.             .+      +      +      + .+ .+       |   
    5e+06 +-+++  ++.++  +  ++.+++.++.+++  +.++.+ +.++.+ +.++.+ +  +  ++.++.+|   
          |                                                                 |   
        0 +-+---------------------------------------------------------------+   
                                                                                
                                                                                                                                                                
                                    perf-stat.ipc                               
                                                                                
  0.465 +-+-----------------------------------------------------------------+   
   0.46 +-++  ++.+ .+++.+          +.+  ++.+ .++. ++  +.++. +.+             |   
        |         +      +.+ .+  ++         +    +         +   :       .++. |   
  0.455 +-+                 +  :+                              +   +.++    +|   
   0.45 +-+                    +                                +.+         |   
        |                                                                   |   
  0.445 +-+                                                                 |   
   0.44 +-+                                                                 |   
  0.435 +-+                                                                 |   
        |                                                                   |   
   0.43 +-+                              O    OO                            |   
  0.425 +-+ O        OO    O   O O   OO    OO    O                          |   
        |  O  O  OO     OO  O O    O                                        |   
   0.42 OO+    O    O             O     O                                   |   
  0.415 +-+-----------------------------------------------------------------+   
                                                                                
                                                                                                                                                                
                                   perf-stat.cpi                                
                                                                                
   2.4 O-+---------O--------------------------------------------------------+   
       |O     O OO               O     O                                    |   
       |  OO O      O  O O  OO     O                                        |   
  2.35 +-+            O   O   O O   O O   O O   O                           |   
       |                                 O   O O                            |   
       |                                                                    |   
   2.3 +-+                                                                  |   
       |                                                                    |   
  2.25 +-+                                                                  |   
       |                                                                    |   
       |                      +                                 +.          |   
   2.2 +-+                 .+ :+                               +  ++.+    .+|   
       |         +.     .++  +  ++.        .+   +.        +.  +       +.++  |   
       |+.+ .++.+  ++.++           ++. +.++  +.+  ++. ++.+  ++              |   
  2.15 +-+------------------------------------------------------------------+   
                                                                                
[*] bisect-good sample
[O] bisect-bad  sample
Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.
Thanks,
Xiaolong
View attachment "config-4.14.0-rc2-00178-gc7b5021" of type "text/plain" (163211 bytes)
View attachment "job-script" of type "text/plain" (6883 bytes)
View attachment "job.yaml" of type "text/plain" (4455 bytes)
View attachment "reproduce" of type "text/plain" (995 bytes)
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