Greeting,

FYI, we noticed a 7.3% improvement of will-it-scale.per_process_ops due to commit:


commit: 097e4311cda952dfb047f2a49d35aa5de500d474 ("perf/x86: Add constraint to create guest LBR event without hw counter")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master


in testcase: will-it-scale
on test machine: 104 threads Skylake with 192G memory
with following parameters:

	nr_task: 100%
	mode: process
	test: signal1
	cpufreq_governor: performance
	ucode: 0x2006906

test-description: Will It Scale takes a testcase and runs it from 1 through to n parallel copies to see if the testcase will scale. It builds both a process and threads based test in order to see any differences between the two.
test-url: https://github.com/antonblanchard/will-it-scale





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

=========================================================================================
compiler/cpufreq_governor/kconfig/mode/nr_task/rootfs/tbox_group/test/testcase/ucode:
  gcc-9/performance/x86_64-rhel-8.3/process/100%/debian-10.4-x86_64-20200603.cgz/lkp-skl-fpga01/signal1/will-it-scale/0x2006906

commit: 
  b2d6504761 ("perf/x86/lbr: Add interface to get LBR information")
  097e4311cd ("perf/x86: Add constraint to create guest LBR event without hw counter")

b2d6504761a50b94 097e4311cda952dfb047f2a49d3 
---------------- --------------------------- 
         %stddev     %change         %stddev
             \          |                \  
     86644            +7.3%      92967        will-it-scale.per_process_ops
   9011113            +7.3%    9668655        will-it-scale.workload
    449.40 ± 36%     +68.3%     756.40 ± 42%  interrupts.CPU58.CAL:Function_call_interrupts
    469.28 ±  5%     -14.3%     402.14 ± 12%  sched_debug.cpu.curr->pid.stddev
      1102 ±  9%     -22.1%     859.00 ± 13%  slabinfo.file_lock_cache.active_objs
      1102 ±  9%     -22.1%     859.00 ± 13%  slabinfo.file_lock_cache.num_objs
     73.00            -2.2%      71.40        vmstat.cpu.sy
     25.00            +5.6%      26.40        vmstat.cpu.us
     18725 ±  2%     +12.6%      21082 ±  5%  softirqs.CPU10.RCU
     18903 ±  3%      +9.3%      20662 ±  3%  softirqs.CPU103.RCU
     20904 ±  2%      +9.5%      22893 ±  3%  softirqs.CPU24.RCU
     20333 ±  8%     +12.1%      22802 ±  2%  softirqs.CPU25.RCU
     20544 ± 13%     +15.9%      23820 ±  3%  softirqs.CPU55.RCU
     17201 ±  9%     +18.4%      20373 ±  5%  softirqs.CPU77.RCU
     18801 ±  4%     +13.8%      21400 ±  8%  softirqs.CPU8.RCU
     21434 ±  2%     +15.0%      24640 ±  7%  softirqs.CPU81.RCU
     18689 ±  3%     +11.3%      20794 ±  4%  softirqs.CPU9.RCU
     18841 ±  2%     +10.8%      20882 ±  3%  softirqs.CPU92.RCU
     18786 ±  2%     +10.7%      20792 ±  3%  softirqs.CPU97.RCU
     18295 ± 11%     +15.0%      21030 ±  4%  softirqs.CPU98.RCU
     18809 ±  2%     +10.0%      20695 ±  2%  softirqs.CPU99.RCU


                                                                                
                            will-it-scale.per_process_ops                       
                                                                                
  98000 +-------------------------------------------------------------------+   
        |  O     O O                                                        |   
  96000 |-+                                                                 |   
        |                                       O    O                      |   
  94000 |-+           O           O O  O  O                                 |   
        |                O  O  O             O     O    O  O  O  O  O O  O  |   
  92000 |-+                                                                 |   
        |                                                                   |   
  90000 |-+                                    .+                           |   
        |                                    +.  :                          |   
  88000 |-+                                 :     :                         |   
        |                                   :     :    .+..+..              |   
  86000 |..             .+..+..+..+.  .+.. :       +.+.       +..+          |   
        |    .+..+.+..+.            +.    +                                 |   
  84000 +-------------------------------------------------------------------+   
                                                                                
                                                                                
[*] 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,
Rong Chen