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 10C82C433EF for ; Tue, 1 Feb 2022 06:33:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 481418D0028; Tue, 1 Feb 2022 01:33:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 430E46B0121; Tue, 1 Feb 2022 01:33:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3201E8D0028; Tue, 1 Feb 2022 01:33:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0005.hostedemail.com [216.40.44.5]) by kanga.kvack.org (Postfix) with ESMTP id 2246E6B0120 for ; Tue, 1 Feb 2022 01:33:42 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id BF5D9824C42D for ; Tue, 1 Feb 2022 06:33:41 +0000 (UTC) X-FDA: 79093245042.26.CA36A57 Received: from mail-ed1-f49.google.com (mail-ed1-f49.google.com [209.85.208.49]) by imf06.hostedemail.com (Postfix) with ESMTP id 59F78180007 for ; Tue, 1 Feb 2022 06:33:41 +0000 (UTC) Received: by mail-ed1-f49.google.com with SMTP id l5so31860359edv.3 for ; Mon, 31 Jan 2022 22:33:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-disposition:in-reply-to:user-agent; bh=JrzOIwB/15hXdxo9+BD6kYpDhXtGeAQrIT7/EdNyUC8=; b=KiOB8OZmozPHe204e845yU6DhE2s2Wii7ARJYDMRtL14WMcLChXIhgUC8V7Sc6qv3c ygZAa9odMWs+SHECpaMYcYiFX2RKQgy2gueKBEfcNJ2YNd06zKBuVOk2+wzrG2OV99vd 4sLfTzxmDxzPh4V6Wq2X0aTg65IbvVqX02+Ez5Ubeld3riS+YfNItXkYYbyoFQQRp4tO dNJSQ0LVj5ZatkwM46bWaMzeU3p9gwsJVctEqK2BJvWb2IIzwTsTNzmGniU3pC1eR8hP 3aQWB6BGEjSe11DSbIpQAn7imGk3yayzkeSqRzjHIs5hxqewKmSPM4FEPgPLBrc2wHZy rOhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:reply-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=JrzOIwB/15hXdxo9+BD6kYpDhXtGeAQrIT7/EdNyUC8=; b=zIumJxQwKysgAr8E0lS9w4Ee9WRdq83nxH6yMUzEzLX/e446l6/Rz4K6zKAHgI2JJT VOymwqhk8aiGiABFwwbJ0UZqm7IqZpwwEgWn1N24ZiXiRrhNAmPhk6SuAzTa5qdPriuN 1ccTJNZG/buX46YBy00CrgnziUalbQ4xnCMyHFs9M6K9q+6eXGz6ObXCoo3SOq72mbOF yjsL0QAKJSojbBbxBbgQ9rFvKtvVViqDSQYEM4NCVegVDEACmd47OYce6Bok98fFPRaM WmBdzwkPS9m8F/8WavwiC47kYICFfbaCtqWM8cL/Iox0GxxjNnnTeCFy1MYooW4ZC4+M yMxA== X-Gm-Message-State: AOAM530MaqOYXmdCweHfB5biUCS/t3wmom74w4yStARopLtvh+MT0LPV KqynsOhUu9h3G8DxB2ayDBo= X-Google-Smtp-Source: ABdhPJz0L77NhTpN2CaRbV3UMUQngiAZFds2CfrdJ3MxZAJnDbRhUE2zdRKHZYmco5hzlmHATJSNsw== X-Received: by 2002:a50:eb82:: with SMTP id y2mr23327756edr.133.1643697219722; Mon, 31 Jan 2022 22:33:39 -0800 (PST) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id fh23sm14300698ejc.176.2022.01.31.22.33.39 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 31 Jan 2022 22:33:39 -0800 (PST) Date: Tue, 1 Feb 2022 06:33:38 +0000 From: Wei Yang To: Michal Hocko Cc: Wei Yang , akpm@linux-foundation.org, mgorman@techsingularity.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/memory_hotplug: build zonelist for managed_zone Message-ID: <20220201063338.u4ux2jsgctuo7tex@master> Reply-To: Wei Yang References: <20220127012023.18095-1-richard.weiyang@gmail.com> <20220129002628.2cwr35glahq5f5md@master> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=KiOB8OZm; spf=pass (imf06.hostedemail.com: domain of richard.weiyang@gmail.com designates 209.85.208.49 as permitted sender) smtp.mailfrom=richard.weiyang@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspam-User: nil X-Rspamd-Queue-Id: 59F78180007 X-Stat-Signature: yksx8bf8m6dz6171edrzqjhrrr9mapb6 X-Rspamd-Server: rspam12 X-HE-Tag: 1643697221-765924 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 Mon, Jan 31, 2022 at 11:24:48AM +0100, Michal Hocko wrote: >> >> This patch restore the original behavior by using the same criteria to >> >> add a zone in zonelist during memory hotplug. >> > >> >Why? >> > >> >> In case we online a populated zone, but not managed. Then this zone will not >> be in zonelist. Right? > >yeah. We can theoretically end up with a zone without any managed menory >on the zonelists. But my primary question is why do we need this change? Currently I don't see a real case for this. >Does it fix any existing problem? Does it make the code easier to >read/understand? Does it improve performance? Every patch should have a >justification. Your changelog merely lists the history and then states >the new behavior without any explanation of why that is needed or >desired. See? I don't have such reason now. >-- >Michal Hocko >SUSE Labs -- Wei Yang Help you, Help me