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From:   Ian Rogers <irogers@google.com>
Date:   Fri, 26 Jun 2020 14:44:14 -0700
Message-ID: <CAP-5=fVMs4Ok3=gYmzheNTzbBUGGHbCr0cpJSm9TV45aeZb4Ng@mail.gmail.com>
Subject: Re: [RFC 00/10] perf tools: Add support to reuse metric
To:     Andi Kleen <ak@linux.intel.com>
Cc:     Jiri Olsa <jolsa@kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Michael Petlan <mpetlan@redhat.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        John Garry <john.garry@huawei.com>,
        "Paul A. Clarke" <pc@us.ibm.com>,
        Stephane Eranian <eranian@google.com>
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On Fri, Jun 26, 2020 at 2:25 PM Andi Kleen <ak@linux.intel.com> wrote:
>
> On Fri, Jun 26, 2020 at 09:47:10PM +0200, Jiri Olsa wrote:
> > hi,
> > this patchset is adding the support to reused metric in another
> > metric. The metric needs to be referenced by 'metric:' prefix.
>
> Why is the prefix needed?
>
> Could just look it up without prefix.

The name could be a metric or an event, the logic for each is quite
different. You could look up an event and when it fails assume it was
a metric, but I like the simplicity of this approach. Maybe this
change could be adopted more widely with something like "perf stat -e
metric:IPC -a -I 1000" rather than the current "perf stat -M IPC -a -I
1000".

Thanks,
Ian

> -Andi