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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 78CF1C433ED for ; Thu, 15 Apr 2021 22:22:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F36BD610F7 for ; Thu, 15 Apr 2021 22:22:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F36BD610F7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7C66D6B0036; Thu, 15 Apr 2021 18:22:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 750376B006C; Thu, 15 Apr 2021 18:22:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C8386B0070; Thu, 15 Apr 2021 18:22:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0133.hostedemail.com [216.40.44.133]) by kanga.kvack.org (Postfix) with ESMTP id 3C3F36B0036 for ; Thu, 15 Apr 2021 18:22:45 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id EFBF618382EB3 for ; Thu, 15 Apr 2021 22:22:44 +0000 (UTC) X-FDA: 78036027048.29.DEC57F8 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf11.hostedemail.com (Postfix) with ESMTP id C191B2000263 for ; Thu, 15 Apr 2021 22:22:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=yCQQJkhIcMUmiG+jHzQ5AkwvKN7ARCVTOi/VwlhPfFg=; b=G7souXSd1HEpHpbqWUh5lxEnqG 72yPOet6m6dISSd7axpLwF1GuIay1RV/45F6tKEj6BDbJeHO2gR22kOlntma0FZZPbcvmmD/MXrGS ZotJA+5b3Jkfa2AaHAwGam44BVigQtO2OUUWx5K1MxtG1pZ5CiucXxAz7iHzXIdBtZHCcO6t1Akn0 Jf6e7BP75Cnv6p6VHUjizlw9iKFlwP1TXfBnuT7H8BBwGli/+jYj8lop4Y87z4ime9iPQZllplUcx wCGblTZ9lVpuPqcW+hkdOWg1I0lN04CeqlSLB7/d6d7euI/yXPCIGsLBBIFSox+o2XhR8MFrZidLv V60jL89w==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lXANH-0099VJ-Ux; Thu, 15 Apr 2021 22:22:19 +0000 Date: Thu, 15 Apr 2021 23:22:11 +0100 From: Matthew Wilcox To: David Laight Cc: Jesper Dangaard Brouer , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "netdev@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mips@vger.kernel.org" , Ilias Apalodimas , Matteo Croce , Grygorii Strashko , Arnd Bergmann , Christoph Hellwig Subject: Re: [PATCH 1/1] mm: Fix struct page layout on 32-bit systems Message-ID: <20210415222211.GG2531743@casper.infradead.org> References: <20210411103318.GC2531743@casper.infradead.org> <20210412011532.GG2531743@casper.infradead.org> <20210414101044.19da09df@carbon> <20210414115052.GS2531743@casper.infradead.org> <20210414211322.3799afd4@carbon> <20210414213556.GY2531743@casper.infradead.org> <20210415200832.32796445@carbon> <20210415182155.GD2531743@casper.infradead.org> <5179a01a462f43d6951a65de2a299070@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5179a01a462f43d6951a65de2a299070@AcuMS.aculab.com> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: C191B2000263 X-Stat-Signature: rdhk4exsfq1y9zhwktde6i55iysq87gn Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf11; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618525353-112123 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 15, 2021 at 09:11:56PM +0000, David Laight wrote: > Isn't it possible to move the field down one long? > This might require an explicit zero - but this is not a common > code path - the extra write will be noise. Then it overlaps page->mapping. See emails passim.