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Message-ID: <02706043-3c81-324d-60a6-ce71a20dfe31@arm.com>
Date:   Wed, 16 Aug 2023 10:16:15 +0100
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Subject: Re: [PATCH v5 5/6] perf vendor events arm64: Update stall_slot
 workaround for N2 r0p3
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To:     John Garry <john.g.garry@oracle.com>,
        linux-perf-users@vger.kernel.org, irogers@google.com,
        renyu.zj@linux.alibaba.com
Cc:     Will Deacon <will@kernel.org>, Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Nick Forrington <nick.forrington@arm.com>,
        Eduard Zingerman <eddyz87@gmail.com>,
        Sohom Datta <sohomdatta1@gmail.com>,
        Rob Herring <robh@kernel.org>, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org
References: <20230811144017.491628-1-james.clark@arm.com>
 <20230811144017.491628-6-james.clark@arm.com>
 <18140960-e8bd-a331-8322-db7254c43bdf@oracle.com>
From:   James Clark <james.clark@arm.com>
In-Reply-To: <18140960-e8bd-a331-8322-db7254c43bdf@oracle.com>
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On 15/08/2023 10:40, John Garry wrote:
> On 11/08/2023 15:39, James Clark wrote:
>> N2 r0p3 doesn't require the workaround [1], so gating on (#slots - 5) no
>> longer works because all N2s have 5 slots. Add a new expression builtin
>> that allows calling strcmp_cpuid_str() and comparing CPUIDs in metric
>> formulas.
>>
>> In this case, the commented formula looks like this:
>>
>>    strcmp_cpuid_str(0x410fd493)        # greater than or equal to N2 r0p3
>>    | strcmp_cpuid_str(0x410fd490) ^ 1  # OR NOT any version of N2
>>
>> [1]:https://urldefense.com/v3/__https://gitlab.arm.com/telemetry-solution/telemetry-solution/-/blob/main/data/pmu/cpu/neoverse/neoverse-n2-r0p3.json__;!!ACWV5N9M2RV99hQ!MaXDALyhn3HmfLdPUZRKTItKxg73C-qP4aTNAAdFwzjW5cFEBTHtD-VyqBzUTFbXMvABB-daDD01AfI7um_BtA$  Signed-off-by: James Clark<james.clark@arm.com>
>> ---
>>   tools/perf/arch/arm64/util/pmu.c               | 18 +-----------------
>>   .../arch/arm64/arm/neoverse-n2-v2/metrics.json |  8 ++++----
>>   tools/perf/pmu-events/metric.py                | 17 +++++++++++++++--
>>   tools/perf/util/expr.c                         | 18 ++++++++++++++++++
>>   tools/perf/util/expr.h                         |  1 +
>>   tools/perf/util/expr.l                         |  1 +
>>   tools/perf/util/expr.y                         |  8 +++++++-
>>   tools/perf/util/pmu.c                          | 17 +++++++++++++++++
>>   tools/perf/util/pmu.h                          |  1 +
>>   9 files changed, 65 insertions(+), 24 deletions(-)
> 
> This patch looks ok, but I think that it would be better to separate out
> the metrics.json change into a separate patch.
> 
Yep I thought about doing that, I can change it in the next version.

> Thanks,
> John