Re: [PATCH v20 00/10] ring-buffer: Making persistent ring buffers robust

From: Google

Date: Thu May 21 2026 - 04:14:07 EST


On Wed, 20 May 2026 14:49:38 -0400
Steven Rostedt <rostedt@xxxxxxxxxx> wrote:

>
> Here is the 20th version of improvement patches for making persistent
> ring buffers robust to failures.
> The previous version is here:
>
> https://lore.kernel.org/all/177751968499.2136606.17388366710182662849.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxx/
>
> None of the patches from the 19th version was changed. Only patches were
> added to it in this version. All of Masami's patches were in version 19,
> and all my patches are new to version 20. The reason I'm including
> Masami's patches with mine is so that Sashiko can handle all of them
> in one go.

Thanks for updating.

BTW, it seems Sashiko is stopping review this series.
https://sashiko.dev/#/patchset/20260520184938.749337513%40kernel.org

Not sure why.

>
> I moved patch 1 from v19 to my urgent branch as it was marked as
> fix for stable.
>
> The patches I added:
>
> - Fix an invalid sub-buffer in the iterator (added TBD fixes tag)
> I didn't want to fold the patch into the patch that was fixed
> as it was written by Masami.
>
> - Have the dropped buffers be persistent across boots. Masami's patches
> cleared the detection of lost subbuffers on boot up and the next
> boot would not show them. If the persistent ring buffer isn't cleared
> it should report the same info on subsequent boots.
>
> - Show [LOST EVENTS] in persistent trace file where a subbuffer was
> reset due to being invalid.
>
> - Show [LOST EVENTS] in the persistent trace_pipe file as well.
>
> Masami Hiramatsu (Google) (6):
> ring-buffer: Skip invalid sub-buffers when validating persistent ring buffer
> ring-buffer: Skip invalid sub-buffers when rewinding persistent ring buffer
> ring-buffer: Add persistent ring buffer invalid-page inject test
> ring-buffer: Show commit numbers in buffer_meta file
> ring-buffer: Cleanup persistent ring buffer validation
> ring-buffer: Cleanup buffer_data_page related code
>
> Steven Rostedt (4):
> ring-buffer: Skip invalid sub-buffers for iterator
> ring-buffer: Have dropped subbuffers be persistent across reboots
> ring-buffer: Show persistent buffer dropped events in trace file
> ring-buffer: Show persistent buffer dropped events in trace_pipe file
>
> ----
> include/linux/ring_buffer.h | 1 +
> kernel/trace/Kconfig | 34 +++
> kernel/trace/ring_buffer.c | 538 +++++++++++++++++++++++++++++---------------
> kernel/trace/trace.c | 4 +
> 4 files changed, 397 insertions(+), 180 deletions(-)


--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>