Re: [PATCH] ring-buffer: Use a housekeeping CPU to wake up waiters

Petr Tesarik
2026-01-09T16:54:28Z

On Fri, 9 Jan 2026 11:15:06 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Fri, 9 Jan 2026 09:57:56 +0100
> Petr Tesarik <ptesarik@suse.com> wrote:
>
> > I have removed both "inline" and "noinline" in v2, leaving it at the
> > discretion of the compiler. If you believe it deserves a "noinline",
> > feel free to add it. FWIW on x86-64, I didn't observe any measurable
> > diference either in latency or instruction cache footprint.
>
> Please add the noinline. I went through and added strategic "noinline" and
> "__always_inline", as well as placing "likely()" and "unlikely()" and
> dropped the cost of adding an event from just under 300ns down to less than
> 150ns.
>
> This code is called during function tracing (hit at every function call),
> and yes, every little bit helps!

I'm going to wait a few days for further comments, then add it in v3.

Thanks for your time!

Petr T