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 4395DEE8012 for ; Fri, 8 Sep 2023 14:46:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240400AbjIHOqr (ORCPT ); Fri, 8 Sep 2023 10:46:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231670AbjIHOqp (ORCPT ); Fri, 8 Sep 2023 10:46:45 -0400 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 795201FC6 for ; Fri, 8 Sep 2023 07:46:40 -0700 (PDT) Received: by mail-wm1-x334.google.com with SMTP id 5b1f17b1804b1-401b5516104so23194665e9.2 for ; Fri, 08 Sep 2023 07:46:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1694184399; x=1694789199; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=50mXa465mShhKVUN1OGI3rygnwhndhPpodqJwLNFdlM=; b=bhFinwQ5g83mgNnOkbpMscmC/dSyZyx0QB1RScScb/J/NZufmm+BsO3e1fl7kq7Z+i xhIT8eBip63hhbz0GDRMswGs925yScA7shhwEEsUF3JV00wHrTHqJVM8KFDB2CjTOlJd UwrneKpmvP4ZXj66lSddCQUhJaAj0PCrNL9x6UykH+NTYcQss3bJ7mPnSt9nUUysKEzk WRRbv5Y4k1XZB2FrHMTkkG9HWWMOB/DgQkxHrJVRoC4exLhUzJVj4GQybOUOM7sEDTRz 2Gyewqj+VWs8a1/ylhSaZf7Rntu1E19G2IFkaqUjm8kydqJaGuRgSXFe3G7MI+olpusG 7yxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694184399; x=1694789199; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=50mXa465mShhKVUN1OGI3rygnwhndhPpodqJwLNFdlM=; b=MLfCHaU53y9txy4Gmmr/n5/TNZDDVXsxZyka+aGhuHlDNNd+uHfgKvvXGBhDCDpvs8 dfngj6xcfDzZo6mXYtA0ueL/sP1+l4zsbaod3V6wP0wU869WZ/ckTxozo9AOk2iES0Be +7d3BPfZ2+6mTl7WQjwXCt9yDwUC3ptefrRsNt3gj+4JE5Q5/h5/Sv9Dh30asK+mCMw7 EGC3In1eX7afvfJgum0efCLaDhTg/SnErEpXW4frd+UL1yFvzDJtdzx6T+mDKjYjPuap qEtORIW381T3TqK/jlfamWWelRr/uVycz3/yElMWDNnt/oMTucjE+Vk5fcVBCToRl/y8 Md2A== X-Gm-Message-State: AOJu0YxJAErtuyJeUMZsBbmPAAr2LmUYWfWxKg4yaJuaDVW072LrroAW umulgkp4tXfHP+F6sV319Y+tfA== X-Google-Smtp-Source: AGHT+IHb2TqDDN9vNv3gtrYNiF8FJajaAj3lPwgPP4md4tkkbeomT6Xa+WZAc1HIbBfi+QbTBKX21w== X-Received: by 2002:a7b:c3cd:0:b0:400:6b36:ee2a with SMTP id t13-20020a7bc3cd000000b004006b36ee2amr2173610wmj.26.1694184398886; Fri, 08 Sep 2023 07:46:38 -0700 (PDT) Received: from [192.168.69.115] (lfb24-h01-176-173-167-175.dsl.sta.abo.bbox.fr. [176.173.167.175]) by smtp.gmail.com with ESMTPSA id g12-20020a7bc4cc000000b003fee849df23sm2160771wmk.22.2023.09.08.07.46.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 08 Sep 2023 07:46:38 -0700 (PDT) Message-ID: <59cc930c-3efd-d31e-49c3-2778914ea9ae@linaro.org> Date: Fri, 8 Sep 2023 16:46:35 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [PATCH v2 0/5] Use nth_page() in place of direct struct page manipulation Content-Language: en-US To: Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org Cc: Andrew Morton , Thomas Bogendoerfer , "Matthew Wilcox (Oracle)" , David Hildenbrand , Mike Kravetz , Muchun Song , "Mike Rapoport (IBM)" References: <20230906150309.114360-1-zi.yan@sent.com> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= In-Reply-To: <20230906150309.114360-1-zi.yan@sent.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 6/9/23 17:03, Zi Yan wrote: > From: Zi Yan > > On SPARSEMEM without VMEMMAP, struct page is not guaranteed to be > contiguous, since each memory section's memmap might be allocated > independently. hugetlb pages can go beyond a memory section size, thus > direct struct page manipulation on hugetlb pages/subpages might give > wrong struct page. Kernel provides nth_page() to do the manipulation > properly. Use that whenever code can see hugetlb pages. How can we notice "whenever code can see hugetlb pages"? From your series it seems you did a manual code audit, is that correct? (I ask because I'm wondering about code scalability and catching other cases). Thanks, Phil.