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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 73D13C2B9F4 for ; Fri, 18 Jun 2021 00:13:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 34946613B4 for ; Fri, 18 Jun 2021 00:13:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34946613B4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=JT2IDVnJw+wdE0hrdecBWlLBczkKeldaiY65IldQvPo=; b=gMlnTXk3DowCazV0bQHtFjkHpp vyoQfBvPg8zx5QwofOh7nePLffZhJ12tEy6Hpt59bCSMuJNdxpjvBAcATE5fOgBCQwtxNjsCeKu1R iOr+aFLklQive8oerOn1j6wzvgrgFGahxszdaHNwKWMJK1+NpxNStIK34A5Y1Q1sgyF/UCYCqhxf/ 6dYBksqOwGraE0tGr+1URElXiHW6srWzFDFtC6bLnjpHrzuTBB8/GsZ3TkHIkjzaWiEz6LCSnG3Ka YaWQXHxmYLXdo9DdZVOxeQM8rWj4f3vjCoserECz+V1EvIomYertaDDnZLG2+oNevpab5+N4YPWva 2zs6nAOg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lu27S-00CAJj-5E; Fri, 18 Jun 2021 00:12:22 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lu27N-00CAHX-3A for linux-arm-kernel@lists.infradead.org; Fri, 18 Jun 2021 00:12:19 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2AD2F610CA; Fri, 18 Jun 2021 00:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623975136; bh=NIkBnZc2GHohfpXgF10FM3cZz9pBdstBWE9sKMqAMu8=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=oSpSYvWFKgBFEmjj8o4qaE7vn+cDY9bhzewS9dKRZoiijkKB/+Yqur25dKFc91Vis ZIPJrkANH3XOikALMkUnqGw2NMPt+2syBcTxRTm5Ev0FPDGtcWXmgcUpH0vvkHEkHG eUQLxuoMVV4FDkRNZtCVHL97C/k/qdnN3cp8bPWJY+iKrsdKwIYHjOzT4a9IqX+lyj i1+y1Xo6wBY0AAm1bUVFS8enJ0mzJMsXotkTh2iJ+ORWNNUbZnA4HZP4xG4dZqoay8 o8Bg5Bxd9kWW/TTPnGN7ihP827CtnDc1xghkjSy+TcwjGKxWA/F7/Q+8IdiRR0jt77 rJUiaJF3kPs9g== Subject: Re: [PATCH 8/8] membarrier: Rewrite sync_core_before_usermode() and improve documentation To: Mathieu Desnoyers Cc: x86 , Dave Hansen , linux-kernel , linux-mm , Andrew Morton , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev , Nicholas Piggin , Catalin Marinas , Will Deacon , linux-arm-kernel , Peter Zijlstra , stable References: <07a8b963002cb955b7516e61bad19514a3acaa82.1623813516.git.luto@kernel.org> <827549827.10547.1623941277868.JavaMail.zimbra@efficios.com> From: Andy Lutomirski Message-ID: <26196903-4aee-33c4-bed8-8bf8c7b46793@kernel.org> Date: Thu, 17 Jun 2021 17:12:15 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <827549827.10547.1623941277868.JavaMail.zimbra@efficios.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210617_171217_233821_20769CC7 X-CRM114-Status: GOOD ( 13.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 6/17/21 7:47 AM, Mathieu Desnoyers wrote: > Please change back this #ifndef / #else / #endif within function for > > if (!IS_ENABLED(CONFIG_ARCH_HAS_MEMBARRIER_SYNC_CORE)) { > ... > } else { > ... > } > > I don't think mixing up preprocessor and code logic makes it more readable. I agree, but I don't know how to make the result work well. membarrier_sync_core_before_usermode() isn't defined in the !IS_ENABLED case, so either I need to fake up a definition or use #ifdef. If I faked up a definition, I would want to assert, at build time, that it isn't called. I don't think we can do: static void membarrier_sync_core_before_usermode() { BUILD_BUG_IF_REACHABLE(); } _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel