Greeting,

FYI, we noticed a -77.9% regression of pft.faults_per_sec_per_cpu due to commit:


commit: e1f8a89c4f33f5b32cfb047f07fdf6d38cda854a ("drm: introduce sync objects (v4)")
git://people.freedesktop.org/~airlied/linux.git drm-syncobj-sem

in testcase: pft
on test machine: qemu-system-x86_64 -enable-kvm -cpu Penryn -smp 4 -m 2G
with following parameters:

	iterations: 20x

test-description: Pft is the page fault test micro benchmark.
test-url: https://github.com/gormanm/pft



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


To reproduce:

        git clone https://github.com/01org/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email

testcase/path_params/tbox_group/run: pft/20x/vm-vp-2G

       v4.12-rc2  e1f8a89c4f33f5b32cfb047f07
----------------  --------------------------
         %stddev     %change         %stddev                                                                                                                                                                                                                                                     \          |                \                                                                                                                                                                                                                                      878620 ± 15%     -77.9%     194209 ± 12%  pft.faults_per_sec_per_cpu
      7.16 ± 23%    +257.2%      25.58 ± 12%  pft.time.elapsed_time
      7.16 ± 23%    +257.2%      25.58 ± 12%  pft.time.elapsed_time.max
      1223 ± 10%    +199.9%       3667 ± 15%  pft.time.involuntary_context_switches
     61828 ±  2%  +10106.0%    6310202 ±  0%  pft.time.minor_page_faults
    145.40 ±  3%     +20.6%     175.33 ±  5%  pft.time.percent_of_cpu_this_job_got
      9.37 ± 22%    +345.2%      41.72 ± 15%  pft.time.system_time
      5.04 ± 11%     -45.6%       2.74 ±  9%  mpstat.cpu.usr%
    131734 ± 12%     +20.3%     158487 ±  5%  softirqs.TIMER                                                                                                                                                                                                                              1335 ± 11%    +105.1%       2738 ± 19%  vmstat.system.cs
      5390 ±  4%     -27.6%       3904 ± 38%  slabinfo.kmalloc-96.active_objs
      5420 ±  3%     -21.5%       4252 ± 27%  slabinfo.kmalloc-96.num_objs
     68.30 ±209%  +13218.2%       9096 ± 84%  latency_stats.max.pipe_read.__vfs_read.vfs_read.SyS_read.entry_SYSCALL_64_fastpath
    588552 ± 32%     -74.2%     151873 ± 37%  latency_stats.sum.ep_poll.SyS_epoll_wait.do_syscall_64.return_from_SYSCALL_64
     74.20 ±203%  +12326.8%       9220 ± 82%  latency_stats.sum.pipe_read.__vfs_read.vfs_read.SyS_read.entry_SYSCALL_64_fastpath
    160550 ± 14%    -100.0%       0.00 ± -1%  meminfo.AnonHugePages
    204792 ±  0%    -100.0%       0.00 ± -1%  meminfo.CmaFree
    204800 ±  0%    -100.0%       0.00 ± -1%  meminfo.CmaTotal
      3041 ±  0%     +13.4%       3449 ±  0%  meminfo.KernelStack
     51198 ±  0%    -100.0%       0.00 ± -1%  proc-vmstat.nr_free_cma
      3033 ±  1%     +13.6%       3446 ±  0%  proc-vmstat.nr_kernel_stack
     73394 ±  9%   +8258.9%    6134982 ±  2%  proc-vmstat.numa_hit
     73394 ±  9%   +8258.9%    6134982 ±  2%  proc-vmstat.numa_local
     67006 ±  9%   +9043.7%    6126912 ±  2%  proc-vmstat.pgfault
     11161 ±  7%    -100.0%       0.00 ± -1%  proc-vmstat.thp_deferred_split_page
     11217 ±  7%    -100.0%       0.00 ± -1%  proc-vmstat.thp_fault_alloc
      7.16 ± 23%    +257.2%      25.58 ± 12%  time.elapsed_time
      7.16 ± 23%    +257.2%      25.58 ± 12%  time.elapsed_time.max
      1223 ± 10%    +199.9%       3667 ± 15%  time.involuntary_context_switches
     61828 ±  2%  +10106.0%    6310202 ±  0%  time.minor_page_faults




                             pft.faults_per_sec_per_cpu

   1e+06 ++--------------------------------------*--------------------------+
  900000 ++                                *..      ..                      |
         |                   *            :           ..                    |
  800000 ++                 : :           :                 ...*            |
  700000 ++  ...*           : :          :              *...                |
         *...    :         :   :         :                                  |
  600000 ++      :         :   :        :                                   |
  500000 ++       :       :     :       :                                   |
  400000 ++       :       :      :     :                                    |
         |         :     :       :     :                                    |
  300000 ++         :   :         :   :                                     |
  200000 O+     O   : O :    O    : O :          O             O            O
         |           : :           : :     O                         O      |
  100000 ++          : :           : :                                      |
       0 ++-----------*-------------*-------------------O-------------------+


 
  [*] 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