On 2/6/2020 4:47 AM, Andi Kleen wrote:
> kernel test robot <rong.a.chen@intel.com> writes:
>
>> Greeting,
>>
>> FYI, we noticed a -2.1% regression of will-it-scale.per_process_ops due to commit:
>>
>>
>> commit: b77491648e6eb2f26b6edf5eaea859adc17f4dcc ("perf x86: Infrastructure for exposing an Uncore unit to PMON mapping")
>> https://github.com/0day-ci/linux/commits/roman-sudarikov-linux-intel-com/perf-x86-Exposing-IO-stack-to-IO-PMON-mapping-through-sysfs/20200118-075508
> Seems to be spurious bisect. I don't think that commit could change
> anything performance related.

Hi Andi,

I commented out some lines in arch/x86/events/intel/uncore.c and 
will-it-scale.per_process_ops increased.

commit:
   v5.4
   b77491648e ("perf x86: Infrastructure for exposing an Uncore unit to PMON mapping")
   f33fe1b258 ("test")


             v5.4  b77491648e6eb2f26b6edf5eae 
f33fe1b258b2a4b2fc97600b2b  testcase/testparams/testbox
----------------  -------------------------- --------------------------  
---------------------------
          %stddev      change         %stddev      change %stddev
              \          |                \          | \
      47983                       47004 47647 
will-it-scale/performance-process-100%-signal1-ucode=0xb000038/lkp-bdw-ep6
      47983                       47004 47647        GEO-MEAN 
will-it-scale.per_process_ops

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 55201bfde2c84c..0dc9c455423d99 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -887,7 +887,7 @@ static int uncore_pmu_register(struct 
intel_uncore_pmu *pmu)
                 pmu->pmu.attr_groups = pmu->type->attr_groups;
         }

-       pmu->pmu.attr_update = attr_update;
+       // pmu->pmu.attr_update = attr_update;

         if (pmu->type->num_boxes == 1) {
                 if (strlen(pmu->type->name) > 0)
@@ -903,7 +903,7 @@ static int uncore_pmu_register(struct 
intel_uncore_pmu *pmu)
          * Exposing mapping of Uncore units to corresponding Uncore PMUs
          * through /sys/devices/uncore_<type>_<idx>/mapping
          */
-       uncore_platform_mapping(pmu->type);
+       // uncore_platform_mapping(pmu->type);

         ret = perf_pmu_register(&pmu->pmu, pmu->name, -1);
         if (!ret)

Best Regards,
Rong Chen

>
> -Andi
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