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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 35B72C433E0 for ; Mon, 15 Jun 2020 15:52:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15D5A207DA for ; Mon, 15 Jun 2020 15:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592236343; bh=8aoTAdf8sVDGVXim6ZnGGER2e0T2HZJlWlL5LqzGsMM=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=wLy7bjyJL1WdyM1NWefVD5u0YVqxQLeNGj/GfN/coFUOgrypLHYf0AK1QH7YUpQAw CCGDGNw2LnntW3uR+ouPy9Hf6HAPwPdeRaHCHIe/S9cTQ4nrKyKO1UJQs2/OxxkPkc 9nG8U9uGUBZ27MAa930AEo4oba6Rpvt4F8g7SDPU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730710AbgFOPwV (ORCPT ); Mon, 15 Jun 2020 11:52:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:53796 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729599AbgFOPwV (ORCPT ); Mon, 15 Jun 2020 11:52:21 -0400 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 CEC67206DB; Mon, 15 Jun 2020 15:52:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592236340; bh=8aoTAdf8sVDGVXim6ZnGGER2e0T2HZJlWlL5LqzGsMM=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=AbWyZrgTOcnBM+QsJ2rCdQ0BQ/HKj81ZvDYn/rYzhsd4BCx5iVbiwgXzrrhBrzpnV uDMkpRSXn3YVApNusBPZ3DpjgP3Il2j5tudd2HF2Q0u62PhR7181I0SjbMZ3ZWAiNF 6yrYdrIjacD3IuMMgVe8vuvh8jPoLUOWMI8evNno= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id B3D063522EFD; Mon, 15 Jun 2020 08:52:20 -0700 (PDT) Date: Mon, 15 Jun 2020 08:52:20 -0700 From: "Paul E. McKenney" To: Peter Zijlstra Cc: tglx@linutronix.de, x86@kernel.org, elver@google.com, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, will@kernel.org, dvyukov@google.com, glider@google.com, andreyknvl@google.com Subject: Re: [PATCH 2/9] rcu: Fixup noinstr warnings Message-ID: <20200615155220.GE2723@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200603114014.152292216@infradead.org> <20200603114051.896465666@infradead.org> <20200603164600.GQ29598@paulmck-ThinkPad-P72> <20200615153052.GY2531@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200615153052.GY2531@hirez.programming.kicks-ass.net> 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 Mon, Jun 15, 2020 at 05:30:52PM +0200, Peter Zijlstra wrote: > On Wed, Jun 03, 2020 at 09:46:00AM -0700, Paul E. McKenney wrote: > > > > // RCU is now watching. Better not be in an extended quiescent state! > > > rcu_dynticks_task_trace_exit(); // After ->dynticks update! > > > WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && > > > !(seq & RCU_DYNTICK_CTRL_CTR)); > > > if (seq & RCU_DYNTICK_CTRL_MASK) { > > > - atomic_andnot(RCU_DYNTICK_CTRL_MASK, &rdp->dynticks); > > > + arch_atomic_andnot(RCU_DYNTICK_CTRL_MASK, &rdp->dynticks); > > > > This one is gone in -rcu. > > I'm still seeing that in mainline, was that removal scheduled for next > round? Yes. Unlike the few commits following it, this commit seems to work fine even with the recent changes in mainline. > > > smp_mb__after_atomic(); /* _exit after clearing mask. */ > > > } > > > } > > What shall we do with this patch? I plan to submit it to the v5.9 merge window. Do you need it to get to mainline earlier? Thanx, Paul