Re: [PATCH v2] perf doc: Document ring buffer mechanism

From: Jonathan Corbet
Date: Thu Aug 03 2023 - 10:36:29 EST

Leo Yan <leo.yan@xxxxxxxxxx> writes:

> 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>
> ---

So this seems like good material from a very brief scan. I do have to
ask, though: why is it not in RST, and why not put it into the
user-space API book?