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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0CD3C433F5 for ; Thu, 19 May 2022 15:37:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241193AbiESPhh (ORCPT ); Thu, 19 May 2022 11:37:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241212AbiESPgQ (ORCPT ); Thu, 19 May 2022 11:36:16 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5C6D66CA8 for ; Thu, 19 May 2022 08:35:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7953EB82291 for ; Thu, 19 May 2022 15:35:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1CCBC385AA; Thu, 19 May 2022 15:35:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652974530; bh=FXXdmKJx9OG/3f612TLCNMeE8xaowuI6lWU8XkiHicE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ewbtFM8ax3OCaWLC8z2u+/La7nmXFmE48clx59622saby+/0dI/bjlvOXOwf8z0eV enZRRJsLYwL1m8aPej6qKglGYkO6EEtLEn8E1snPxFrZFri9Ueow5FFXrNbbXpkms0 DYnyjWHj8bni3of5Dtko6YkAG6A2CKveCzm+lhafUQ00mPZo12h0ujV8IcukjYZh0w nXCCIYtlkmvwb0Qf98fvAi2k/qlfhqB1wMYrVJ6qGiWtpbhRWi1bwjHCNebiCeNJ0L d12nBqZsFbkzavkPTyLbMw0xgTKAHke29SouPBWfJYOMBjW875f5rKRWhqT/29bu25 cPwJ5vnnyIv/g== Date: Thu, 19 May 2022 17:35:27 +0200 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: Peter Zijlstra , LKML , Phil Auld , Alex Belits , Nicolas Saenz Julienne , Xiongfeng Wang , Neeraj Upadhyay , Thomas Gleixner , Yu Liao , Boqun Feng , Marcelo Tosatti , Paul Gortmaker , Uladzislau Rezki , Joel Fernandes Subject: Re: [PATCH 03/21] rcu: Add a note about noinstr VS unsafe eqs functions Message-ID: <20220519153527.GE618878@lothringen> References: <20220503100051.2799723-1-frederic@kernel.org> <20220503100051.2799723-4-frederic@kernel.org> <20220519145438.GJ2578@worktop.programming.kicks-ass.net> <20220519152611.GY1790663@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220519152611.GY1790663@paulmck-ThinkPad-P17-Gen-1> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 19, 2022 at 08:26:11AM -0700, Paul E. McKenney wrote: > On Thu, May 19, 2022 at 04:54:38PM +0200, Peter Zijlstra wrote: > > On Tue, May 03, 2022 at 12:00:33PM +0200, Frederic Weisbecker wrote: > > > Some RCU functions enter or exit into/from RCU idle mode while using > > > trace-able and lockdep-aware IRQs (un-)masking. This could be easily > > > solved with using raw versions of local_irq_*() but we would then > > > lose some precious debugging informations. > > > > > > Another possible way to solve this may consist in using rude RCU-tasks > > > in lockdep and irqsoff tracing. > > > > > > In any case and until this get solved, those RCU functions can't get > > > tagged as noinstr even though they should. > > > > FWIW, this also means RCU_NONIDLE() is broken. Luckily there aren't many > > users left. > > More to the point, rcu_irq_enter_irqson() and rcu_irq_exit_irqson() need > the same help that rcu_idle_enter() and rcu_idle_exit() got earlier this > week [1], independent of RCU_NONIDLE(). > > Unless Frederic beats me to it, I will queue something up. It's in the patchset I just posted (02/21). > > Thanx, Paul > > [1] https://lore.kernel.org/all/20220518162118.GA2661055@paulmck-ThinkPad-P17-Gen-1/