Re: [PATCH 1/3] perf vendor events: For the Neoverse N2

[John Garry <john.garry@huawei.com>]

On 07/12/2021 12:13, Andrew Kilroy wrote:
> On 07/12/2021 09:57, John Garry wrote:
>> On 03/12/2021 12:35, Andrew Kilroy wrote:
>>> Updates the common and microarch json file to add counters
>>> available in the Neoverse N2 chip, but should also apply to other ArmV8
>>> and ArmV9 cpus.  Specified in ArmV8 architecture reference manual
>>>
>>> https://developer.arm.com/documentation/ddi0487/gb/?lang=en
>>>
>>> Some of the counters added to armv8-common-and-microarch.json are
>>> specified in the ArmV9 architecture reference manual supplement
>>> (issue A.a):
>>>
>>> https://developer.arm.com/documentation/ddi0608/aa
>>>
>>> The additional ArmV9 counters are
>>>
>>>    TRB_WRAP
>>>    TRCEXTOUT0
>>>    TRCEXTOUT1
>>>    TRCEXTOUT2
>>>    TRCEXTOUT3
>>>    CTI_TRIGOUT4
>>>    CTI_TRIGOUT5
>>>    CTI_TRIGOUT6
>>>    CTI_TRIGOUT7
>>>
>>> This patch also adds files in pmu-events/arch/arm64/arm/neoverse-n2 for
>>> perf list to output the counter names in categories.
>>>
>>> A subsequent patch renames armv8-common-and-microarch.json and
>>> armv8-recommended.json to reflect that counters for armv9 are being
>>> added.
>>
>> This commentary should be in a cover letter. Please do that.
>>
>> And did you consider just adding a armv9-common-and-microarch.json and
>> armv9-recommended.json instead of adding to and renaming the v8 version?
>> I know that it creates scattered definitions, but we already have that in
>> dividing the common and the recommended JSONs.
>>
> 
> I considered it, but I wasn't sure what was preferable.  I thought I'd 
> get some feedback.  Do you consider the separation important?  Any 
> particular reason?

At the moment I don't think that it's a big issue. I just thought it 
better to keep a structured and distinct file organisation by having 
separate files. v9 stuff is quite new, so we can wait for other input here.

Thanks,
John