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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham 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 61778C2BA83 for ; Wed, 12 Feb 2020 14:29:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DDEB206D7 for ; Wed, 12 Feb 2020 14:29:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728284AbgBLO3z (ORCPT ); Wed, 12 Feb 2020 09:29:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:45712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727851AbgBLO3z (ORCPT ); Wed, 12 Feb 2020 09:29:55 -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 D87982082F; Wed, 12 Feb 2020 14:29:53 +0000 (UTC) Date: Wed, 12 Feb 2020 09:29:52 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: 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, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com Subject: Re: [PATCH 8/8] tracing: Remove regular RCU context for _rcuidle tracepoints (again) Message-ID: <20200212092952.7bec74e9@gandalf.local.home> In-Reply-To: <20200212094108.063885035@infradead.org> References: <20200212093210.468391728@infradead.org> <20200212094108.063885035@infradead.org> 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, 12 Feb 2020 10:32:18 +0100 Peter Zijlstra wrote: > Effectively revert commit 865e63b04e9b2 ("tracing: Add back in > rcu_irq_enter/exit_irqson() for rcuidle tracepoints") now that we've > taught perf how to deal with not having an RCU context provided. > > Signed-off-by: Peter Zijlstra (Intel) > --- > include/linux/tracepoint.h | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > --- a/include/linux/tracepoint.h > +++ b/include/linux/tracepoint.h > @@ -179,10 +179,8 @@ static inline struct tracepoint *tracepo > * For rcuidle callers, use srcu since sched-rcu \ > * doesn't work from the idle path. \ > */ \ > - if (rcuidle) { \ > + if (rcuidle) \ > __idx = srcu_read_lock_notrace(&tracepoint_srcu);\ > - rcu_irq_enter_irqsave(); \ > - } \ > \ > it_func_ptr = rcu_dereference_raw((tp)->funcs); \ > \ > @@ -194,10 +192,8 @@ static inline struct tracepoint *tracepo > } while ((++it_func_ptr)->func); \ > } \ > \ > - if (rcuidle) { \ > - rcu_irq_exit_irqsave(); \ > + if (rcuidle) \ > srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\ > - } \ > \ > preempt_enable_notrace(); \ > } while (0) > Which looks basically the same as this patch... https://lore.kernel.org/r/20200211095047.58ddf750@gandalf.local.home -- Steve