Re: [PATCH v3] perf doc: Document ring buffer mechanism

From: Ingo Molnar
Date: Tue Oct 03 2023 - 05:22:59 EST



* Leo Yan <leo.yan@xxxxxxxxxx> 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@xxxxxxxxxx>
> ---
>
> 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@xxxxxxxxxx>

Thanks,

Ingo