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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 E033EC34050 for ; Wed, 19 Feb 2020 16:43:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9E5324656 for ; Wed, 19 Feb 2020 16:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582130638; bh=fAUXneFS52k57grboibuKNlhx4KWqafEVfvJ/w5AT5E=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=tKqXjP6hbNmjRTwNHAnIh5XQlJYa3zg2vcG/XLAFfPrPnUS8cg+S9VXixciCGeCzi k4IaOJcTOScNJrx65VPgxvsHNIHtGBUWbeATzmqeaLPrjWLAP/ICqpV5rOH5LuYDqx ca4OJcA4uDOZ8/ptahZ8gq1zvmLorL49yCnvcqfo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726826AbgBSQn5 (ORCPT ); Wed, 19 Feb 2020 11:43:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:33574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726551AbgBSQn5 (ORCPT ); Wed, 19 Feb 2020 11:43:57 -0500 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (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 9B82220578; Wed, 19 Feb 2020 16:43:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582130636; bh=fAUXneFS52k57grboibuKNlhx4KWqafEVfvJ/w5AT5E=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=kuSn/LOFoBhhdEPgeun9ja5OvUWXD7yfhI+m0hwq0OG7HITXzdZcqDzEha5xVF+8L cxTlYhnPysyrpUv2ud4GCj0C87SzbHN9w/X4+x8EK3dTjZh8m2ZuCcOQhcfYZzLOCC HP1md8SgMLZ0McuwNVkHhjsE5XKFPy/6uYkYO7NE= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 6FF0135209B0; Wed, 19 Feb 2020 08:43:56 -0800 (PST) Date: Wed, 19 Feb 2020 08:43:56 -0800 From: "Paul E. McKenney" To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.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: <20200219164356.GB2935@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200219144724.800607165@infradead.org> <20200219150745.125119627@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200219150745.125119627@infradead.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 19, 2020 at 03:47:37PM +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 Shouldn't we also get rid of this line above? int __maybe_unused __idx = 0; \ Thanx, Paul > * 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) > >