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,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 03DA8C4BA09 for ; Wed, 26 Feb 2020 00:23:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C629824670 for ; Wed, 26 Feb 2020 00:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582676605; bh=zbZcGwuBk0lpjSX3xx+Kk+TiKNLbzSLEzDkIp/A8uBI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=pzAcu/vOIBchWJ14k38/E/ijeiAiwsTd6c98b9pFXXsy3QZi270g8aYoIxZ+U3to5 0vO77lB+4O34gBLSsu8/4wzVffM8vny8xjnnlrvligGrGwe405aN5TCPgjlN8eS6/r 3XInr3dtCWkNryuIV9n80ROGbLK7esTzdc0L32gY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729403AbgBZAXY (ORCPT ); Tue, 25 Feb 2020 19:23:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:42720 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728989AbgBZAXY (ORCPT ); Tue, 25 Feb 2020 19:23:24 -0500 Received: from localhost (lfbn-ncy-1-985-231.w90-101.abo.wanadoo.fr [90.101.63.231]) (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 3008421927; Wed, 26 Feb 2020 00:23:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582676603; bh=zbZcGwuBk0lpjSX3xx+Kk+TiKNLbzSLEzDkIp/A8uBI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oF2U/sSNT9K/Apq5Wxz/T8L9uh8Z/5Qi0PGNjDY/2i+LA4nf4rvFHmUKKPojDTzB2 4djz/6XCrYTvUY/EiELLJTkp6CTeDFwA1u2yTjPvrroSafyINVWvpS2xuZ4oE10+q9 3b1h8492D8CXOSGJEcT0FLxr3vXA94CXI6bdCYbQ= Date: Wed, 26 Feb 2020 01:23:21 +0100 From: Frederic Weisbecker 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, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, dan.carpenter@oracle.com, mhiramat@kernel.org Subject: Re: [PATCH v4 07/27] rcu: Make RCU IRQ enter/exit functions rely on in_nmi() Message-ID: <20200226002320.GC9599@lenoir> References: <20200221133416.777099322@infradead.org> <20200221134215.443368893@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200221134215.443368893@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 Fri, Feb 21, 2020 at 02:34:23PM +0100, Peter Zijlstra wrote: > From: Paul E. McKenney > > The rcu_nmi_enter_common() and rcu_nmi_exit_common() functions take an > "irq" parameter that indicates whether these functions are invoked from > an irq handler (irq==true) or an NMI handler (irq==false). However, > recent changes have applied notrace to a few critical functions such > that rcu_nmi_enter_common() and rcu_nmi_exit_common() many now rely > on in_nmi(). Note that in_nmi() works no differently than before, > but rather that tracing is now prohibited in code regions where in_nmi() > would incorrectly report NMI state. > > This commit therefore removes the "irq" parameter and inlines > rcu_nmi_enter_common() and rcu_nmi_exit_common() into rcu_nmi_enter() > and rcu_nmi_exit(), respectively. > > Signed-off-by: Paul E. McKenney > Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Frederic Weisbecker Although in the end, from a naming POV, it would make more sense to have rcu_nmi_enter() calling rcu_irq_enter() rather than the opposite. But the result would be another level of function in the way to keep the NOKPROBE property, so I guess we'll stick with that layout.