From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 135E9C34056 for ; Wed, 19 Feb 2020 18:00:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EB1FC24670 for ; Wed, 19 Feb 2020 18:00:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726700AbgBSSAQ (ORCPT ); Wed, 19 Feb 2020 13:00:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:54892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726582AbgBSSAP (ORCPT ); Wed, 19 Feb 2020 13:00:15 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D502024656; Wed, 19 Feb 2020 18:00:13 +0000 (UTC) Date: Wed, 19 Feb 2020 13:00:12 -0500 From: Steven Rostedt To: "Paul E. McKenney" Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org Subject: Re: [PATCH v3 13/22] tracing: Remove regular RCU context for _rcuidle tracepoints (again) Message-ID: <20200219130012.116670fd@gandalf.local.home> In-Reply-To: <20200219174025.GJ2935@paulmck-ThinkPad-P72> References: <20200219144724.800607165@infradead.org> <20200219150745.125119627@infradead.org> <20200219164356.GB2935@paulmck-ThinkPad-P72> <20200219164736.GL18400@hirez.programming.kicks-ass.net> <20200219170507.GH14946@hirez.programming.kicks-ass.net> <20200219122116.7aeaf230@gandalf.local.home> <20200219174025.GJ2935@paulmck-ThinkPad-P72> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19 Feb 2020 09:40:25 -0800 "Paul E. McKenney" wrote: > > Correct, and if rcuidle is not set, and this is a macro, the SRCU > > portion is compiled out. > > Sigh! Apologies for the noise! > > If we are using SRCU, we don't care whether or not RCU is watching. OK, > maybe finally catching up -- the whole point was use of RCU in other > tracing code, wasn't it? Some callbacks (namely perf) might use RCU, but then the callbacks need to make sure rcu is watching. -- Steve