Re: [PATCH] tools/perf/metricgroup: Fix printing event names of metric group with multiple events

[kajoljain <kjain@linux.ibm.com>]

On 12/11/19 7:15 PM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Dec 04, 2019 at 12:25:22PM +0530, Ravi Bangoria escreveu:
>>
>> On 11/20/19 2:10 PM, Kajol Jain wrote:
>>> Commit f01642e4912b ("perf metricgroup: Support multiple
>>> events for metricgroup") introduced support for multiple events
>>> in a metric group. But with the current upstream, metric events
>>> names are not printed properly
>>>
>>> In power9 platform:
>>> command:# ./perf stat --metric-only -M translation -C 0 -I 1000 sleep 2
>>>        1.000208486
>>>        2.000368863
>>>        2.001400558
>>>
>>> Similarly in skylake platform:
>>> command:./perf stat --metric-only -M Power -I 1000
>>>        1.000579994
>>>        2.002189493
>>>
>>> With current upstream version, issue is with event name comparison
>>> logic in find_evsel_group(). Current logic is to compare events
>>> belonging to a metric group to the events in perf_evlist.
>>> Since the break statement is missing in the loop used for comparison
>>> between metric group and perf_evlist events, the loop continues to
>>> execute even after getting a pattern match, and end up in discarding
>>> the matches.
>>> Incase of single metric event belongs to metric group, its working fine,
>>> because in case of single event once it compare all events it reaches to
>>> end of perf_evlist.
>>>
>>> Example for single metric event in power9 platform
>>> command:# ./perf stat --metric-only  -M branches_per_inst -I 1000 sleep 1
>>>        1.000094653                  0.2
>>>        1.001337059                  0.0
>>>
>>> Patch fixes the issue by making sure once we found all events
>>> belongs to that metric event matched in find_evsel_group(), we
>>> successfully break from that loop by adding corresponding condition.
>>>
>>> With this patch:
>>> In power9 platform:
>>>
>>> command:# ./perf stat --metric-only -M translation -C 0 -I 1000 sleep 2
>>> result:#           time derat_4k_miss_rate_percent  derat_4k_miss_ratio
>>>        derat_miss_ratio derat_64k_miss_rate_percent derat_64k_miss_ratio
>>>            dslb_miss_rate_percent islb_miss_rate_percent
>>>        1.000135672                         0.0                  0.3
>>>                     1.0                          0.0                  0.2
>>>                    0.0                     0.0
>>>        2.000380617                         0.0                  0.0
>>>                                                 0.0                  0.0
>>>                   0.0                     0.0
>>>
>>> command:# ./perf stat --metric-only -M Power -I 1000
>>>
>>> Similarly in skylake platform:
>>> result:#           time    Turbo_Utilization    C3_Core_Residency
>>>               C6_Core_Residency    C7_Core_Residency     C2_Pkg_Residency
>>>                C3_Pkg_Residency     C6_Pkg_Residency     C7_Pkg_Residency
>>>        1.000563580                  0.3                  0.0
>>>                     2.6                44.2                 21.9
>>>                     0.0                  0.0                  0.0
>>>        2.002235027                  0.4                  0.0
>>>                     2.7           43.0                 20.7
>>>                     0.0                  0.0               0.0
>>>
>>> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
>>> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
>>> Cc: Andi Kleen <ak@linux.intel.com>
>>> Cc: Jiri Olsa <jolsa@kernel.org>
>>> Cc: Kan Liang <kan.liang@linux.intel.com>
>>> Cc: Peter Zijlstra <peterz@infradead.org>
>>> Cc: Jin Yao <yao.jin@linux.intel.com>
>>> Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
>>> Cc: Anju T Sudhakar <anju@linux.vnet.ibm.com>
>>> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
>> Fixes: f01642e4912b ("perf metricgroup: Support multiple events for metricgroup")
>> Reviewed-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
> Tested on a Skylake machine and applied.
>
>> But while looking at the patch, I found that, commit f01642e4912b
>> has (again) screwed up logic for metric with overlapping events.
> Is someone looking into this?


Hi Arnaldo,

             I am looking  into this issue and will post the fix soon.

Kajol

>   
>>    $ sudo ./perf stat -M UPI,IPC sleep 1
>>
>>     Performance counter stats for 'sleep 1':
>>
>>             948,650      uops_retired.retire_slots
>>             866,182      inst_retired.any          #      0.7 IPC
>>             866,182      inst_retired.any
>>           1,175,671      cpu_clk_unhalted.thread
>>
>> This also needs to be fixed.
>>
>> Ravi