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=-5.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,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 A8CB0C433DB for ; Thu, 21 Jan 2021 13:12:36 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 40BEE239FD for ; Thu, 21 Jan 2021 13:12:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 40BEE239FD 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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=OxMCtAnj29OajkdW5e7GplebwcjjyYt0OsCPRrjQu6k=; b=LXhDiVxw/7qCHiLaIJ4dow60o vqPO0Ici7IKPOr260tEMAyVW3dnYmGHrhfcuZ8Y400b8oRdtAkkXF/Opo+XdfWS7xedYI6aVDtxR9 gnzgUYY1WT7zjTLpU83Vaw3aM20YuhpjNt35JmuYu6mNkvblMWLsRVP78i+FlfW5BlLJYpvc2X7Sb ACm/WXGc2qjb966w46yrs4xq6hNrjBN2e48mf/uzkgHDQDpqfJ4pKf8LHHrjUvulqJ+9lpsdEeBv9 cSVOyq2MRZqXnKHSD5eiHR57dG16I6MVc90Jytf4fz+mwzTDfh5AOUgi0pg3ym4pBsejEywrHWeTa ydXnpSsWg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2Zk0-0004tg-FJ; Thu, 21 Jan 2021 13:11:12 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2Zjx-0004t8-8d for linux-arm-kernel@lists.infradead.org; Thu, 21 Jan 2021 13:11:10 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id B3DCA239FD; Thu, 21 Jan 2021 13:11:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611234667; bh=2y3nGlOhKVuLqnNjQEH4fvR9yoxLXv3W74n69qv+ztU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DMGerGrEyeuqZjQcioHC6qJlSjxztZkPOzz9rPBbGMGM4CrCsv2OoPx+nqbx/5U6V qqnUASiYhMVlSFup3Xtd+GhMe9vouxtjgM5xEUoC6vloFLyuBsYJMqoV6HDsfK2Jwt s+Fn9tbQHe7o+zXPgNW3OjfJ3quFDKohpqwKv0OVYn2/OrqHoFw8VXYruoZLw0NJQs NnxmPBHMheaB9NLaz2p2IamJL7YC3LegARCqCn5DcSxRv6Ta0fLczedsj26scJmFLN hmuJp9osXG++3J9N+kDY72bLNkZ3z2e6KAhFY9IiGFany5cGQ8RQH4E7acxjU2EdIO Im3FHP1GKDehg== Date: Thu, 21 Jan 2021 13:11:01 +0000 From: Will Deacon To: Linus Torvalds , luc.vanoostenryck@gmail.com Subject: Re: [PATCH v4 8/8] mm: Mark anonymous struct field of 'struct vm_fault' as 'const' Message-ID: <20210121131101.GD22123@willie-the-truck> References: <20210120173612.20913-1-will@kernel.org> <20210120173612.20913-9-will@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210121_081109_393864_41F3997D X-CRM114-Status: GOOD ( 16.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , Minchan Kim , Catalin Marinas , Nick Desaulniers , LKML , Linux Memory Management List , Vinayak Menon , Hugh Dickins , "Kirill A . Shutemov" , Andrew Morton , kernel-team , Linux ARM 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 Wed, Jan 20, 2021 at 11:02:06AM -0800, Linus Torvalds wrote: > On Wed, Jan 20, 2021 at 10:27 AM Nick Desaulniers > wrote: > > > > Is there a difference between: [ const unnamed struct and individual const members ] > > Semantically? No. > > Syntactically the "group the const members together" is a lot cleaner, > imho. Not just from a "just a single const" standpoint, but from a > "code as documentation" standpoint. > > But I guess to avoid the clang issue, we could do the "mark individual > fields" thing. I'd prefer to wait until the bug against LLVM has been resolved before we try to work around anything. Although I couldn't find any other examples like this in the kernel, requiring all of the member fields to be marked as 'const' still feels pretty fragile to me; it's only a matter of time before new non-const fields get added, at which point the temptation for developers to remove 'const' from other fields when it gets in the way is pretty high. None of this is bullet-proof, of course, but if clang ends up emitting a warning (even if it's gated behind an option) then I think we're in a good place. > (It turns out that sparse gets this wrong too, so it's not just clang). Adding Luc, as hopefully that's fixable. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel