Re: [PATCH v7 8/8] perf vendor events: Add JSON metrics for Arm CMN

[Jing Zhang]

在 2023/8/25 下午12:13, Ian Rogers 写道:
> On Mon, Aug 21, 2023 at 1:36 AM Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx> wrote:
>>
>> Add JSON metrics for Arm CMN. Currently just add part of CMN PMU
>> metrics which are general and compatible for any SoC with CMN-ANY.
>>
>> Signed-off-by: Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx>
>> Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>
>> ---
>>  .../pmu-events/arch/arm64/arm/cmn/sys/metric.json  | 74 ++++++++++++++++++++++
>>  1 file changed, 74 insertions(+)
>>  create mode 100644 tools/perf/pmu-events/arch/arm64/arm/cmn/sys/metric.json
>>
>> diff --git a/tools/perf/pmu-events/arch/arm64/arm/cmn/sys/metric.json b/tools/perf/pmu-events/arch/arm64/arm/cmn/sys/metric.json
>> new file mode 100644
>> index 0000000..64db534
>> --- /dev/null
>> +++ b/tools/perf/pmu-events/arch/arm64/arm/cmn/sys/metric.json
>> @@ -0,0 +1,74 @@
>> +[
>> +       {
>> +               "MetricName": "slc_miss_rate",
>> +               "BriefDescription": "The system level cache miss rate.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "hnf_cache_miss / hnf_slc_sf_cache_access",
>> +               "ScaleUnit": "100%",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
> 
> Here a ';' is used as a separator, but for "Unit" ',' is used as a
> separator. Is there a reason for the inconsistency?
> 

John and I have previously discussed this issue, and in fact, I deliberately used ';'.

I use a semicolon instead of a comma because I want to distinguish it from the function
of the comma in "Unit" and avoid confusion between the use of commas in "Unit" and "Compat".
Because in Unit, commas act as wildcards, and in “Compat”, the semicolon means "or". So
I think semicolons are more appropriate.

Thanks,
Jing

> Thanks,
> Ian
> 
>> +       },
>> +       {
>> +               "MetricName": "hnf_message_retry_rate",
>> +               "BriefDescription": "HN-F message retry rate indicates whether a lack of credits is causing the bottlenecks.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "hnf_pocq_retry / hnf_pocq_reqs_recvd",
>> +               "ScaleUnit": "100%",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       },
>> +       {
>> +               "MetricName": "sf_hit_rate",
>> +               "BriefDescription": "Snoop filter hit rate can be used to measure the snoop filter efficiency.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "hnf_sf_hit / hnf_slc_sf_cache_access",
>> +               "ScaleUnit": "100%",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       },
>> +       {
>> +               "MetricName": "mc_message_retry_rate",
>> +               "BriefDescription": "The memory controller request retries rate indicates whether the memory controller is the bottleneck.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "hnf_mc_retries / hnf_mc_reqs",
>> +               "ScaleUnit": "100%",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       },
>> +       {
>> +               "MetricName": "rni_actual_read_bandwidth.all",
>> +               "BriefDescription": "This event measure the actual bandwidth that RN-I bridge sends to the interconnect.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "rnid_rxdat_flits * 32 / 1e6 / duration_time",
>> +               "ScaleUnit": "1MB/s",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       },
>> +       {
>> +               "MetricName": "rni_actual_write_bandwidth.all",
>> +               "BriefDescription": "This event measures the actual write bandwidth at RN-I bridges.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "rnid_txdat_flits * 32 / 1e6 / duration_time",
>> +               "ScaleUnit": "1MB/s",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       },
>> +       {
>> +               "MetricName": "rni_retry_rate",
>> +               "BriefDescription": "RN-I bridge retry rate indicates whether the memory controller is the bottleneck.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "rnid_txreq_flits_retried / rnid_txreq_flits_total",
>> +               "ScaleUnit": "100%",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       },
>> +       {
>> +               "MetricName": "sbsx_actual_write_bandwidth.all",
>> +               "BriefDescription": "sbsx actual write bandwidth.",
>> +               "MetricGroup": "cmn",
>> +               "MetricExpr": "sbsx_txdat_flitv * 32 / 1e6 / duration_time",
>> +               "ScaleUnit": "1MB/s",
>> +               "Unit": "arm_cmn",
>> +               "Compat": "434*;436*;43c*;43a*"
>> +       }
>> +]
>> --
>> 1.8.3.1
>>