
FYI, we noticed a -32.0% decrease of xfstests.generic.017.seconds due to commit:

commit 0a2aa8fbb9693020b822ac7a23755591554eaea5 ("f2fs: refactor __exchange_data_block for speed up")
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

in testcase: xfstests
on test machine: 4 threads Sandy Bridge with 6G memory
with following parameters:

	disk: 4HDD
	fs: f2fs
	test: generic-mid1


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.

Details are as below:
-------------------------------------------------------------------------------------------------->


To reproduce:

        git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
        cd lkp-tests
        bin/lkp install job.yaml  # job file is attached in this email
        bin/lkp run     job.yaml

=========================================================================================
compiler/disk/fs/kconfig/rootfs/tbox_group/test/testcase:
  gcc-6/4HDD/f2fs/x86_64-rhel/debian-x86_64-2015-02-07.cgz/snb-drag/generic-mid1/xfstests

commit: 
  1d353eb7e4 ("f2fs: fix ERR_PTR returned by bio")
  0a2aa8fbb9 ("f2fs: refactor __exchange_data_block for speed up")

1d353eb7e4385333 0a2aa8fbb9693020b822ac7a23 
---------------- -------------------------- 
       fail:runs  %reproduction    fail:runs
           |             |             |    
          %stddev     %change         %stddev
             \          |                \  
    134.25 ą  0%     -32.0%      91.33 ą  1%  xfstests.generic.017.seconds
    496.95 ą  0%      -8.8%     453.16 ą  0%  xfstests.time.elapsed_time
    496.95 ą  0%      -8.8%     453.16 ą  0%  xfstests.time.elapsed_time.max
     41.00 ą  0%     -13.8%      35.33 ą  1%  xfstests.time.percent_of_cpu_this_job_got
    164.68 ą  0%     -26.6%     120.88 ą  0%  xfstests.time.system_time


                           xfstests.generic.017.seconds

  160 ++------------------------------------*----*----*---------------------+
      *..*.*     *.*..*..*..*.*..*..*.*..*.   *.    *    *..*..             |
  140 ++   :     :                                             *.*..*..*.*..*
  120 ++   :     :                                                          |
      |     :   :                                                           |
  100 ++    :   :                                                           |
      |     :   :                                              O O     O    |
   80 O+ O O: O :O O  O  O  O O  O  O O  O  O O  O  O O  O  O               |
      |      : :                                                            |
   60 ++     : :                                                            |
   40 ++     : :                                                            |
      |      : :                                                            |
   20 ++      :                                                             |
      |       :                                                             |
    0 ++------*-----------------------------------------------------O-------+


	[*] bisect-good sample
	[O] bisect-bad  sample


Thanks,
Xiaolong