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Date:   Thu, 5 Jan 2023 19:02:04 +0800
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Subject: Re: [PATCH v5 1/6] perf vendor events arm64: Add topdown L1 metrics
 for neoverse-n2
To:     John Garry <john.g.garry@oracle.com>,
        Ian Rogers <irogers@google.com>,
        Xing Zhengjun <zhengjun.xing@linux.intel.com>,
        Will Deacon <will@kernel.org>,
        James Clark <james.clark@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.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>,
        Andrew Kilroy <andrew.kilroy@arm.com>,
        Shuai Xue <xueshuai@linux.alibaba.com>,
        Zhuo Song <zhuo.song@linux.alibaba.com>
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From:   Jing Zhang <renyu.zj@linux.alibaba.com>
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在 2023/1/5 下午6:13, John Garry 写道:
> Maybe during runtime we could create a pseudo metric/event for SLOT. This metric would be created during init, and it always just returns the value which was read from PMMIR_EL1.
> 
> I'm not sure how well that would play will trying to resolve metrics when building generated pmu-events.c, but I don't think it's all too difficult to achieve.
> 

I'll try it in the v7 patch. I want to release the v6 patch first, to correct a mistake I made. :)

> Have you actually read this value for the n2 core? Does look correct?

Yes, I read it in n2 and it has a value of 5 which is correct. If the
STALL_SLOT event is not implemented, PMMIR_EL1.SLOT might read as zero.