Message-ID: <e7aaacd8-7972-6ab9-ff0c-e286bf23993a@arm.com>
Date:   Tue, 7 Dec 2021 12:13:16 +0000
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Subject: Re: [PATCH 1/3] perf vendor events: For the Neoverse N2
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To:     John Garry <john.garry@huawei.com>, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org, acme@kernel.org
Cc:     Will Deacon <will@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-arm-kernel@lists.infradead.org
References: <20211203123525.31127-1-andrew.kilroy@arm.com>
 <2e1a7a96-4ec6-e1f2-5bd4-133480391053@huawei.com>
From:   Andrew Kilroy <andrew.kilroy@arm.com>
In-Reply-To: <2e1a7a96-4ec6-e1f2-5bd4-133480391053@huawei.com>
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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?


> Thanks,
> John

Andrew