Re: [PATCH v5 11/24] perf vendor events: Update/add Graniterapids events/metrics

["Liang, Kan" <kan.liang@linux.intel.com>]

On 2025-02-05 4:33 p.m., Ian Rogers wrote:
> On Wed, Feb 5, 2025 at 1:10 PM Liang, Kan <kan.liang@linux.intel.com> wrote:
>>
>> On 2025-02-05 3:23 p.m., Ian Rogers wrote:
>>> On Wed, Feb 5, 2025 at 11:11 AM Liang, Kan <kan.liang@linux.intel.com> wrote:
>>>>
>>>> On 2025-02-05 12:31 p.m., Ian Rogers wrote:
>>>>> +    {
>>>>> +        "BriefDescription": "This category represents fraction of slots utilized by useful work i.e. issued uops that eventually get retired",
>>>>> +        "MetricExpr": "topdown\\-retiring / (topdown\\-fe\\-bound + topdown\\-bad\\-spec + topdown\\-retiring + topdown\\-be\\-bound) + 0 * slots",
>>>>> +        "MetricGroup": "BvUW;TmaL1;TopdownL1;tma_L1_group",
>>>>> +        "MetricName": "tma_retiring",
>>>>> +        "MetricThreshold": "tma_retiring > 0.7 | tma_heavy_operations > 0.1",
>>>>> +        "MetricgroupNoGroup": "TopdownL1",
>>>>> +        "PublicDescription": "This category represents fraction of slots utilized by useful work i.e. issued uops that eventually get retired. Ideally; all pipeline slots would be attributed to the Retiring category.  Retiring of 100% would indicate the maximum Pipeline_Width throughput was achieved.  Maximizing Retiring typically increases the Instructions-per-cycle (see IPC metric). Note that a high Retiring value does not necessary mean there is no room for more performance.  For example; Heavy-operations or Microcode Assists are categorized under Retiring. They often indicate suboptimal performance and can often be optimized or avoided. Sample with: UOPS_RETIRED.SLOTS",
>>>>> +        "ScaleUnit": "100%"
>>>>> +    },
>>>>
>>>> The "Default" tag is missed for GNR as well.
>>>> It seems the new CPUIDs are not added in the script?
>>>
>>> Spotted it, we need to manually say which architectures with TopdownL1
>>> should be in Default because it was insisted upon that pre-Icelake
>>> CPUs with TopdownL1 not have TopdownL1 in Default. As you know, my
>>> preference would be to always put TopdownL1 metrics into Default.
>>>
>>
>> For the future platforms, there should be always at least TopdownL1
>> support. Intel even adds extra fixed counters for the TopdownL1 events.
>>
>> Maybe the script should be changed to only mark the old pre-Icelake as
>> no TopdownL1 Default. For the other platforms, always add TopdownL1 as
>> Default. It would avoid manually adding it for every new platforms.
> 
> That's fair. What about TopdownL2 that is currently only in the
> Default set for SPR?
> 

Yes, the TopdownL2 is a bit tricky, which requires much more events.
Could you please set it just for SPR/EMR/GNR for now?

I will ask around internally and make a long-term solution for the
TopdownL2.

Thanks,
Kan