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

Steven Rostedt
2026-01-09T16:14:44Z

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!

-- Steve