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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1BFCC3DA7A for ; Fri, 6 Jan 2023 19:45:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8BC718E0002; Fri, 6 Jan 2023 14:45:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 86C648E0001; Fri, 6 Jan 2023 14:45:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7344F8E0002; Fri, 6 Jan 2023 14:45:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 61E058E0001 for ; Fri, 6 Jan 2023 14:45:13 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 29493A0EA5 for ; Fri, 6 Jan 2023 19:45:13 +0000 (UTC) X-FDA: 80325402906.01.202162C Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf16.hostedemail.com (Postfix) with ESMTP id 89BCE180008 for ; Fri, 6 Jan 2023 19:45:11 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ClubDpXF; spf=pass (imf16.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1673034311; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0Ff2Em2e780MnbPxJkQK0yqrgQr3w9/nZLRfATfYnys=; b=Ajp4EVbMQRdFZqLk5D7s3KWyBVwxt/PCITDir7aGPv4ZL8wiuxFstEdYveFwUu8m9uYfIu Cw7qOseRx0IBLHUsXGmJFTQZ+MZ3c+it1Qs+RUlI8K+vekOq5Kvj2Gm9w8rb3GxNQY8Wff 2WltpUDgK5nHTLqgUTuSYUaoTqRkyFc= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ClubDpXF; spf=pass (imf16.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1673034311; a=rsa-sha256; cv=none; b=vp6moRWy8/7RFQU3nelqi5WBq4KEiHhw0f+FedzPutQbPi7Q8+sW1EpGTvglYZ4UgNvHYB XcO/zEGcTfQjzciAIKebMQxmZyoUO7BgLc85yslPbwYXcMTX+k9G+n4CkFpQDlGjU2s4GZ UbGRmKvNxPSv6vWRGxj9ZEZE4Ae5kL8= Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 52ABC61F34; Fri, 6 Jan 2023 19:45:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D61DC433F0; Fri, 6 Jan 2023 19:45:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673034310; bh=t0QJHS7GzsG7gBvvc1iRFnu9kKXmKbMthB+oLe/zMrU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ClubDpXF/Vrt9mJSv/Ng0sby1fhChk0b4adVRKYL+dSg27G2D42WT90pQ0K9CaKWD 6phQju/a5jjJfNFxNt5xPqB4Lq2BnJZ2OqW5Wxal8t/23vn6iwsqmRI6znewtj+AJv A1mdxD7nM31PQAT7eX/MukbOucerLccq8T0NH+yTLMRaG+1xSa0J3HF3WcuBci7C5V e2B3B95K42UuxU1yUPdkpI5BjgZtSzAyTlIULrcYN1tPGVQzA7B4q+zKItBTQLNDUK 885Mw+JMhoEf08DwlguDGtF97yUFvab1yV9PhnURgtKzGMd/yIdixJAsmnajsYnvgX cCQrLvS713LkQ== From: SeongJae Park To: Matthew Wilcox Cc: SeongJae Park , Andrew Morton , Xiubo Li , Ilya Dryomov , Jeff Layton , linux-mm@kvack.org, ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] add folio_headpage() macro Date: Fri, 6 Jan 2023 19:45:07 +0000 Message-Id: <20230106194507.152468-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 89BCE180008 X-Stat-Signature: zm8memzt6qge87a3pgdqpxi1ohe538j7 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1673034311-874361 X-HE-Meta: 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 puWCpilk UTYCMNll53HFx/vexv/r6FEVWIRK4XNR77wkmfsWFlZlDfm0dASQyzc2LuyTx/ck/9F1bZqlwFi0u2Q0FHgqmAiB3vH2r4FTBU7yrGNOVNmNQRgqAUkXag1kmTw== 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 Fri, 6 Jan 2023 19:21:40 +0000 Matthew Wilcox wrote: > On Fri, Jan 06, 2023 at 05:40:25PM +0000, SeongJae Park wrote: > > The standard idiom for getting head page of a given folio is > > '&folio->page'. It is efficient and safe even if the folio is NULL, > > because the offset of page field in folio is zero. However, it makes > > the code not that easy to understand at the first glance, especially the > > NULL safety. Also, sometimes people forget the idiom and use > > 'folio_page(folio, 0)' instead. To make it easier to read and remember, > > add a new macro function called 'folio_headpage()' with the NULL case > > explanation. Then, replace the 'folio_page(folio, 0)' calls with > > 'folio_headpage(folio)'. > > No. Everywhere that uses &folio->page is a place that needs to be fixed. > It shouldn't have a nice convenience macro. It should make you mildly > uncomfortable. It's true that it's just a mild uncomfortableness. I will respect your opinion here. Thanks for the input. Thanks, SJ