Re: [PATCH 2/6] tools/perf/json: Add cache metrics for s390 z16

From: Thomas Richter
Date: Wed Mar 15 2023 - 03:22:14 EST


On 3/14/23 17:34, Ian Rogers wrote:
> On Tue, Mar 14, 2023 at 1:20 AM Thomas Richter <tmricht@xxxxxxxxxxxxx> wrote:
>>
>> On 3/13/23 19:33, Arnaldo Carvalho de Melo wrote:
>>> Em Mon, Mar 13, 2023 at 08:22:44AM -0700, Ian Rogers escreveu:
>>>> On Mon, Mar 13, 2023 at 1:30 AM Thomas Richter <tmricht@xxxxxxxxxxxxx> wrote:
>>>>>
>>>>> Add metrics for s390 z16
>>>>> - Percentage sourced from Level 2 cache
>>>>> - Percentage sourced from Level 3 on same chip cache
>>>>> - Percentage sourced from Level 4 Local cache on same book
>>>>> - Percentage sourced from Level 4 Remote cache on different book
>>>>> - Percentage sourced from memory
>>>>>
>>>>> For details about the formulas see this documentation:
>>>>> https://www.ibm.com/support/pages/system/files/inline-files/CPU%20MF%20Formulas%20including%20z16%20-%20May%202022_1.pdf
>>>>>
>>>>> Outpuf after:
>>>>> # ./perf stat -M l4rp -- dd if=/dev/zero of=/dev/null bs=10M count=10K
>>>>> .... dd output deleted
>>>>>
>>>>> Performance counter stats for 'dd if=/dev/zero of=/dev/null bs=10M count=10K':
>>>>>
>>>>> 0 IDCW_OFF_DRAWER_CHIP_HIT # 0.00 l4rp
>>>>> 431,866 L1I_DIR_WRITES
>>>>> 2,395 IDCW_OFF_DRAWER_IV
>>>>> 0 ICW_OFF_DRAWER
>>>>> 0 IDCW_OFF_DRAWER_DRAWER_HIT
>>>>> 1,437 DCW_OFF_DRAWER
>>>>> 425,960,793 L1D_DIR_WRITES
>>>>>
>>>>> 12.165030699 seconds time elapsed
>>>>>
>>>>> 0.001037000 seconds user
>>>>> 12.162140000 seconds sys
>>>>>
>>>>> #
>>>>>
>>>>> Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
>>>>> Acked-By: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
>>>>
>>>> Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
>>>
>>> Thanks, applied the first two patches, please address the review
>>> suggestions for patches 3-6 and resubmit only those.
>>>
>>> The patches will be in the public perf-tools-next branch later today.
>>>
>>> - Arnaldo
>>>
>>
>> I would really prefer the current implementation without using "ScaleUnit": "100%"
>> The reason is that these formulars are given to me from the s390 Performance team.
>> They want to use the exact same formulars on all platforms running on s390
>> which includes z/OS and z/VM. This way they are sure to get the same numbers.
>>
>> Hope this background info helps.
>
> For the series:
> Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> Using ScaleUnit won't change the result. A ScaleUnit of "100%" means
> scale the result up by multiplying by 100 and then apply the % after
> the value. Another nit is having metrics that place their units in the
> name, like _percent, is usually a sign the name can be better. Perhaps
> we can follow up with some clean up.
>
> Thanks,
> Ian

Thanks Ian,
I put the ScaleUnit thing on my todo list and will provide a clean up...

--
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
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