Re: [PATCH RFC 0/4] Add JSON metrics for arm CMN and Yitian710 DDR

[Jing Zhang]

在 2023/3/28 上午12:51, Ian Rogers 写道:
> On Sun, Mar 26, 2023 at 7:46 PM Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx> wrote:
>>
>> Hi all,
>>
>> I add an identifier sysfs file for the yitian710 SoC DDR and arm CMN to
>> allow userspace to identify the specific implementation of the device,
>> so that the perf tool can match the corresponding uncore events and
>> metrics through the identifier. Then added several general CMN700 metrics
>> and yitian710 soc DDR metrics.
> 
> Thanks!
> 
>> Since the eventid of cmn700 events is different from other events, it
>> can't be specified by "EventCode" or "ConfigCode", so in the cmn.json
>> file of cmn700, no "EventCode" and "ConfigCode" are added for these
>> events. For example, the eventid of "arm_cmn_0/hnf_sf_hit is/":
>> cat /sys/bus/event_source/devices/arm_cmn_0/events/hnf_sf_hit
>> type=0x5,eventid=0x6
> 
> This is done to add descriptions to the events? We can add encodings
> to jevents.py and the event parsing to handle the names eventid and
> type.
> 

Ok, I will try it.

>> In addition, both cmn700 and ddr PMU can count the information in a die,
>> but the same SoC can also be configured with different numbers of dies,
>> so it is dificult to design a general expression to obtain metrics in
>> different dies. The current yitian710 ddr bandwidth metric describes the
>> sum of all dies bandwidth. I would like to ask you, is there any general
>> expression can obtain metrics for die? Add an option to specify die?
> 
> So hopefully the logic for this is getting clearer in the
> perf-tools-next branch. When perf stat runs it will aggregate in a
> number of different ways, if you pass -A it will remove the
> aggregation, but you can also use --per-socket, per-die, .. The
> metrics take the individual counter values, say instructions and
> cycles and produce a metric like IPC. By default all the instruction
> counts are aggregated together, the cycles are aggregated together and
> then the metric produced on the two aggregated values. When -A or
> --per-die are passed, the appropriate amount of aggregation should be
> done then the metric computed multiple times.
> 

Thanks! It is helpful. It solved my problem.

Thanks,
Jing

> Are you asking for a way in a metric to take counts from one die and
> use them in the other's metric? For example, reads on one die are
> writes on the other? This is possible as we have all the counts in the
> tool. I've thought about this in the context of some metrics we have
> for AMD, but there is no support for this in the tool currently.
> 
> Thanks,
> Ian
> 
>> Thanks,
>> Jing
>>
>> Jing Zhang (4):
>>   driver/perf: Add identifier sysfs file for CMN
>>   perf vendor events: Add JSON metrics for cmn700
>>   driver/perf: Add identifier sysfs file for Yitian 710 DDR
>>   perf vendor events: Add JSON metrics for Yitian 710 DDR
>>
>>  drivers/perf/alibaba_uncore_drw_pmu.c              |  27 ++
>>  drivers/perf/arm-cmn.c                             |  43 +++
>>  .../pmu-events/arch/arm64/arm/cmn700/sys/cmn.json  | 188 +++++++++++
>>  .../arch/arm64/arm/cmn700/sys/metrics.json         |  74 ++++
>>  .../arm64/freescale/yitian710/sys/ali_drw.json     | 373 +++++++++++++++++++++
>>  .../arm64/freescale/yitian710/sys/metrics.json     |  20 ++
>>  tools/perf/pmu-events/jevents.py                   |   2 +
>>  7 files changed, 727 insertions(+)
>>  create mode 100644 tools/perf/pmu-events/arch/arm64/arm/cmn700/sys/cmn.json
>>  create mode 100644 tools/perf/pmu-events/arch/arm64/arm/cmn700/sys/metrics.json
>>  create mode 100644 tools/perf/pmu-events/arch/arm64/freescale/yitian710/sys/ali_drw.json
>>  create mode 100644 tools/perf/pmu-events/arch/arm64/freescale/yitian710/sys/metrics.json
>>
>> --
>> 1.8.3.1
>>