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Sender: Ingo Molnar <mingo.kernel.org@gmail.com>
Date:   Tue, 3 Oct 2023 11:22:51 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     Leo Yan <leo.yan@linaro.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Thomas Richter <tmricht@linux.ibm.com>,
        Ingo Molnar <mingo@redhat.com>,
        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>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v3] perf doc: Document ring buffer mechanism
Message-ID: <ZRvda2QwdFYCp1F1@gmail.com>
References: <20230803114613.1786849-1-leo.yan@linaro.org>
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* Leo Yan <leo.yan@linaro.org> wrote:

> In the Linux perf tool, the ring buffer serves not only as a medium for
> transferring PMU event data but also as a vital mechanism for hardware
> tracing using technologies like Intel PT and Arm CoreSight, etc.
> 
> Consequently, the ring buffer mechanism plays a crucial role by ensuring
> high throughput for data transfer between the kernel and user space
> while avoiding excessive overhead caused by the ring buffer itself.
> 
> This commit documents the ring buffer mechanism in detail.  It provides
> an in-depth explanation of the implementation of both the generic ring
> buffer and the AUX ring buffer.  Additionally, it covers how these ring
> buffers support various tracing modes and explains the synchronization
> with memory barriers.
> 
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
> 
> Changes from v2:
> - Refined doc for Thomas's suggestions (Thomas Richter).
> 
> Changes from v1:
> - Addressed Ian's comments and suggestions (Ian Rogers).
> 
> 
>  tools/perf/Documentation/perf-ring-buffer.txt | 762 ++++++++++++++++++
>  1 file changed, 762 insertions(+)
>  create mode 100644 tools/perf/Documentation/perf-ring-buffer.txt

Nice addition!

If it hasn't been picked up yet:

  Acked-by: Ingo Molnar <mingo@kernel.org>

Thanks,

	Ingo