Re: [PATCH v6 04/24] tracing: Add reset to trace remotes

Steven Rostedt
2025-09-10T16:44:35Z

On Wed, 10 Sep 2025 10:45:05 +0100
Vincent Donnefort <vdonnefort@google.com> wrote:

> > If we are gonna keep the "trace" file, let's make sure it's fully
> > implemented.
>
> I was more worry about the ring-buffer page order that can be reshuffled on each
> swap_reader_page(), making the page links useless in the kernel. Ideally, the
> meta-page would keep the page ID order somewhere.

Yeah, internally we could keep the order of the pages. Shouldn't be too
hard, as the swapping happens by the kernel.

>
> Alternatively, we could walk all the buffer pages to read the timestamp and
> re-create the order but that sounds quite cumbersome.

No, having a separate array of the order is probably what we want. Then
every swap_reader_page() will update the array. The trace iterator could
simply walk that array.

-- Steve