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References: <20240102085001.228815-1-leo.yan@linaro.org>
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From: Namhyung Kim <namhyung@kernel.org>
Date: Fri, 5 Jan 2024 15:12:20 -0800
Message-ID: <CAM9d7cg3Qkx240RBGKYegeX-kxgUiQ4-G4R3sJBc=w=o-Msk=Q@mail.gmail.com>
Subject: Re: [PATCH v8] Documentation: userspace-api: Document perf ring
 buffer mechanism
To: Leo Yan <leo.yan@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>, Arnaldo Carvalho de Melo <acme@kernel.org>, Ian Rogers <irogers@google.com>, 
	Thomas Richter <tmricht@linux.ibm.com>, Peter Zijlstra <peterz@infradead.org>, 
	Adrian Hunter <adrian.hunter@intel.com>, Jiri Olsa <jolsa@kernel.org>, 
	Ingo Molnar <mingo@kernel.org>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-perf-users@vger.kernel.org
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Hi Leo,

On Tue, Jan 2, 2024 at 12:50=E2=80=AFAM 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 explains
> the implementation of both the regular 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>

Thanks a lot for working on this!

Reviewed-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung