From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@kernel.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ian Rogers <irogers@google.com>,
Namhyung Kim <namhyung@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@kernel.org>,
Douglas Raillard <douglas.raillard@arm.com>
Subject: Re: [POC][RFC][PATCH 1/3] tracing: Add perf events
Date: Tue, 18 Nov 2025 08:42:26 -0500 [thread overview]
Message-ID: <20251118084226.1e531c4b@gandalf.local.home> (raw)
In-Reply-To: <20251118083510.GI3245006@noisy.programming.kicks-ass.net>
On Tue, 18 Nov 2025 09:35:10 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
> > + cpu = smp_processor_id();
> > +
> > + e = per_cpu_ptr(events, cpu)->event;
> > + if (!e)
> > + return 0;
> > +
> > + e->pmu->read(e);
> > + return local64_read(&e->count);
> > +}
>
> NAK, wtf do you think its okay to use internal stuff like that? And
> wrongly while at it.
Peter, this is a PROOF-OF-CONCEPT. It means I'm showing the concept and not
the implementation. I'm hoping the NAK is on the implementation and not the
concept.
>
> What you wanted to use was perf_event_read_local().
Great! I didn't know about that. Which is why I posted this as a
PROOF-OF-CONCEPT and not even a normal RFC, so that I could learn about the
proper way of doing this.
-- Steve
next prev parent reply other threads:[~2025-11-18 13:42 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-18 0:29 [POC][RFC][PATCH 0/3] tracing: Add perf events to trace buffer Steven Rostedt
2025-11-18 0:29 ` [POC][RFC][PATCH 1/3] tracing: Add perf events Steven Rostedt
2025-11-18 8:35 ` Peter Zijlstra
2025-11-18 13:42 ` Steven Rostedt [this message]
2025-11-18 20:24 ` Steven Rostedt
2025-11-18 0:29 ` [POC][RFC][PATCH 2/3] ftrace: Add perf counters to function tracing Steven Rostedt
2025-11-18 0:29 ` [POC][RFC][PATCH 3/3] fgraph: Add perf counters to function graph tracer Steven Rostedt
2025-11-18 3:08 ` [POC][RFC][PATCH 0/3] tracing: Add perf events to trace buffer Masami Hiramatsu
2025-11-18 3:42 ` Steven Rostedt
2025-11-18 8:11 ` Masami Hiramatsu
2025-11-18 13:53 ` Steven Rostedt
2025-11-18 13:57 ` Steven Rostedt
2025-11-18 16:31 ` Steven Rostedt
2025-11-18 7:25 ` Namhyung Kim
2025-11-18 16:24 ` Steven Rostedt
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