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Date:   Wed, 2 Feb 2022 10:33:13 +0000
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Subject: Re: [PATCH v9] libperf: Add arm64 support to perf_mmap__read_self()
To:     Rob Herring <robh@kernel.org>, Will Deacon <will@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@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>
CC:     Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>,
        <linux-perf-users@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20220201214056.702854-1-robh@kernel.org>
From:   John Garry <john.garry@huawei.com>
In-Reply-To: <20220201214056.702854-1-robh@kernel.org>
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On 01/02/2022 21:40, Rob Herring wrote:
> Add the arm64 variants for read_perf_counter() and read_timestamp().
> Unfortunately the counter number is encoded into the instruction, so the
> code is a bit verbose to enumerate all possible counters.
> 
> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
> Signed-off-by: Rob Herring <robh@kernel.org>

Ha, I was just looking at this same topic yesterday from an old patchset 
[0] and wasn't aware of this separate change.

Tested-by: John Garry <john.garry@huawei.com>

[0] https://lore.kernel.org/all/20210311000837.3630499-1-robh@kernel.org/

BTW, Documentation/arm64/perf.rst has a reference to a file which does 
not seem to exit:

.. _tools/perf/arch/arm64/tests/user-events.c:
 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/arch/arm64/tests/user-events.c

Thanks,
john