From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AF6935580A; Tue, 18 Nov 2025 13:42:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763473334; cv=none; b=Nds9FU9HYKA4EimYrDRKi+uLWkP9AbSdFCYy2K8sGCjFyA/+nsNGH/Wywmb6jvd4CfLborQRiCgkBSMPFIqXiXV9Nc+ajKXJcKEXsB+xHN4f/eKIkwTvK50zQPEXU9ZbNeNiDGeIwk6qfiQGQdp6jzwxEmsfpNwheSmI1t0bXm0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763473334; c=relaxed/simple; bh=Um04pVU7wsUE982wDvPeRRijkwcDQcIfgXubQOjBSMY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rj/pMWGvomUfT3X9Ew31eKDLZhiwcyhVsToRDuYdfpL66p18dL1jpUHFiWTMpU7l+3ewh38sJCpcwNw26g7W/s9D1i7OhPw7PHeu/99YAIV4kq/pX1x0qU3yqJ2Dah/udVZX1yAyVq2OkH9Paashg1HrqIkb4ehepzmMmJ4MA5I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C7E2DC0552; Tue, 18 Nov 2025 13:42:03 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf15.hostedemail.com (Postfix) with ESMTPA id 133351A; Tue, 18 Nov 2025 13:42:00 +0000 (UTC) Date: Tue, 18 Nov 2025 08:42:26 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: Steven Rostedt , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Thomas Gleixner , Ian Rogers , Namhyung Kim , Arnaldo Carvalho de Melo , Jiri Olsa , Douglas Raillard Subject: Re: [POC][RFC][PATCH 1/3] tracing: Add perf events Message-ID: <20251118084226.1e531c4b@gandalf.local.home> In-Reply-To: <20251118083510.GI3245006@noisy.programming.kicks-ass.net> References: <20251118002950.680329246@kernel.org> <20251118003531.644484343@kernel.org> <20251118083510.GI3245006@noisy.programming.kicks-ass.net> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: 133351A X-Stat-Signature: aeb1soab6d7rawe8asosexj7k1c1thm6 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/B+CQkLgTlVRE55r//DwkLri7yWbR0H9E= X-HE-Tag: 1763473320-650899 X-HE-Meta: U2FsdGVkX1+eDlRh1IDLMVEp5KpbMIrSr7EXuynOECOUejEx2Hy77n5rMpmWfTEaZZozla0ppcO1uUJdaq0oJ+g4Pe8/9vJWZHwj2sA4YOW8bkQhhtqu6+WIogIo11rvcpJcHvwPVxovrA2h4zFH4oomqXUlHoElCrhwbnkxYTv6cJOqdsvl2KmHuoD05gvP5CqzXUSNtJZH4joPSat6lZhUvcIf9JrcMWNXQEVSCmjhK+QGLOsfdJGckkGr9CzU00k9wxMTM2QLeQ2gryhzti1W1DwZTCu4C9RgG/lItwLWwwr9WhDPl7HPBVL36JzOUF1sXlerHTlMSaBKi6rmwtPtpAKngcW6rH34Gu8TTvsLQlWc1Hh11r4swrUMQv1E On Tue, 18 Nov 2025 09:35:10 +0100 Peter Zijlstra 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