Re: [PATCH] perf vendor events: Update datasource event name to fix duplicate events

[Athira Rajeev <atrajeev@linux.vnet.ibm.com>]

> On 27-Nov-2023, at 5:32 PM, Disha Goel <disgoel@linux.ibm.com> wrote:
> 
> On 23/11/23 9:31 pm, Athira Rajeev wrote:
> 
>> Running "perf list" on powerpc fails with segfault
>> as below:
>> 
>>    ./perf list
>>    Segmentation fault (core dumped)
>> 
>> This happens because of duplicate events in the json list.
>> The powerpc Json event list contains some event with same
>> event name, but different event code. They are:
>> - PM_INST_FROM_L3MISS (Present in datasource and frontend)
>> - PM_MRK_DATA_FROM_L2MISS (Present in datasource and marked)
>> - PM_MRK_INST_FROM_L3MISS (Present in datasource and marked)
>> - PM_MRK_DATA_FROM_L3MISS (Present in datasource and marked)
>> 
>> pmu_events_table__num_events uses the value from
>> table_pmu->num_entries which includes duplicate events as
>> well. This causes issue during "perf list" and results in
>> segmentation fault.
>> 
>> Since both event codes are valid, append _DSRC to the Data
>> Source events (datasource.json), so that they would have a
>> unique name. Also add PM_DATA_FROM_L2MISS_DSRC and
>> PM_DATA_FROM_L3MISS_DSRC events. With the fix, perf list
>> works as expected.
>> 
>> Fixes: fc1435807533 ("perf vendor events power10: Update JSON/events")
>> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> 
> I have tested the patch on Power10 machine. Perf list works correctly without any segfault now.
> 
> # ./perf list
> 
> List of pre-defined events (to be used in -e or -M):
> 
>   branch-instructions OR branches                    [Hardware event]
>   branch-misses                                      [Hardware event]
> 
> Tested-by: Disha Goel <disgoel@linux.ibm.com>
> 

Thanks Disha for testing

Athira
>> ---
>>  .../arch/powerpc/power10/datasource.json       | 18 ++++++++++++++----
>>  1 file changed, 14 insertions(+), 4 deletions(-)
>> 
>> diff --git a/tools/perf/pmu-events/arch/powerpc/power10/datasource.json b/tools/perf/pmu-events/arch/powerpc/power10/datasource.json
>> index 6b0356f2d301..0eeaaf1a95b8 100644
>> --- a/tools/perf/pmu-events/arch/powerpc/power10/datasource.json
>> +++ b/tools/perf/pmu-events/arch/powerpc/power10/datasource.json
>> @@ -99,6 +99,11 @@
>>      "EventName": "PM_INST_FROM_L2MISS",
>>      "BriefDescription": "The processor's instruction cache was reloaded from a source beyond the local core's L2 due to a demand miss."
>>    },
>> +  {
>> +    "EventCode": "0x0003C0000000C040",
>> +    "EventName": "PM_DATA_FROM_L2MISS_DSRC",
>> +    "BriefDescription": "The processor's L1 data cache was reloaded from a source beyond the local core's L2 due to a demand miss."
>> +  },
>>    {
>>      "EventCode": "0x000380000010C040",
>>      "EventName": "PM_INST_FROM_L2MISS_ALL",
>> @@ -161,9 +166,14 @@
>>    },
>>    {
>>      "EventCode": "0x000780000000C040",
>> -    "EventName": "PM_INST_FROM_L3MISS",
>> +    "EventName": "PM_INST_FROM_L3MISS_DSRC",
>>      "BriefDescription": "The processor's instruction cache was reloaded from beyond the local core's L3 due to a demand miss."
>>    },
>> +  {
>> +    "EventCode": "0x0007C0000000C040",
>> +    "EventName": "PM_DATA_FROM_L3MISS_DSRC",
>> +    "BriefDescription": "The processor's L1 data cache was reloaded from beyond the local core's L3 due to a demand miss."
>> +  },
>>    {
>>      "EventCode": "0x000780000010C040",
>>      "EventName": "PM_INST_FROM_L3MISS_ALL",
>> @@ -981,7 +991,7 @@
>>    },
>>    {
>>      "EventCode": "0x0003C0000000C142",
>> -    "EventName": "PM_MRK_DATA_FROM_L2MISS",
>> +    "EventName": "PM_MRK_DATA_FROM_L2MISS_DSRC",
>>      "BriefDescription": "The processor's L1 data cache was reloaded from a source beyond the local core's L2 due to a demand miss for a marked instruction."
>>    },
>>    {
>> @@ -1046,12 +1056,12 @@
>>    },
>>    {
>>      "EventCode": "0x000780000000C142",
>> -    "EventName": "PM_MRK_INST_FROM_L3MISS",
>> +    "EventName": "PM_MRK_INST_FROM_L3MISS_DSRC",
>>      "BriefDescription": "The processor's instruction cache was reloaded from beyond the local core's L3 due to a demand miss for a marked instruction."
>>    },
>>    {
>>      "EventCode": "0x0007C0000000C142",
>> -    "EventName": "PM_MRK_DATA_FROM_L3MISS",
>> +    "EventName": "PM_MRK_DATA_FROM_L3MISS_DSRC",
>>      "BriefDescription": "The processor's L1 data cache was reloaded from beyond the local core's L3 due to a demand miss for a marked instruction."
>>    },
>>    {