From: Petr Tesarik <ptesarik@suse.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Clark Williams <clrkwllms@kernel.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev
Subject: Re: [PATCH] ring-buffer: Use a housekeeping CPU to wake up waiters
Date: Fri, 9 Jan 2026 17:54:23 +0100 [thread overview]
Message-ID: <20260109175423.70ba42d7@mordecai> (raw)
In-Reply-To: <20260109111506.66ad545a@gandalf.local.home>
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
prev parent reply other threads:[~2026-01-09 16:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-06 9:10 [PATCH] ring-buffer: Use a housekeeping CPU to wake up waiters Petr Tesarik
2026-01-06 22:04 ` Steven Rostedt
2026-01-07 7:50 ` Petr Tesarik
2026-01-07 9:51 ` Petr Tesarik
2026-01-07 16:17 ` Steven Rostedt
2026-01-07 16:19 ` Steven Rostedt
2026-01-08 8:39 ` Petr Tesarik
2026-01-08 10:46 ` Petr Tesarik
2026-01-08 16:58 ` Steven Rostedt
2026-01-09 8:57 ` Petr Tesarik
2026-01-09 16:15 ` Steven Rostedt
2026-01-09 16:54 ` Petr Tesarik [this message]
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