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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 425A8C43387 for ; Tue, 8 Jan 2019 01:53:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F0C420827 for ; Tue, 8 Jan 2019 01:53:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="HaGahGz4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727289AbfAHBxM (ORCPT ); Mon, 7 Jan 2019 20:53:12 -0500 Received: from mail-qt1-f193.google.com ([209.85.160.193]:41483 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727028AbfAHBxL (ORCPT ); Mon, 7 Jan 2019 20:53:11 -0500 Received: by mail-qt1-f193.google.com with SMTP id l12so2768578qtf.8 for ; Mon, 07 Jan 2019 17:53:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=BdxXWNWCwXyo34zuyi/62cZr4j0t4y4EbTTp2nD/nis=; b=HaGahGz44oE0fxzBNLN0yUZ9MDPjizLeil/LqGMZ89R5dr3TAC6TkukiBmznTcNvA2 BaldlFiapj3RaF7a4iLB0+i3e+yRdLxWDzVkwhqfx2dn+UhfMC9U5uNBDzU75g8TAk5q oZBvxUUT+eo2K/57tWRmAY7oPWZSWBHgSR+iosAY3RQpP/hU/AaXqgCnxpkYO9G1xIwb EljSk7ZQMGNSWKNQpahSJO/UE3GnD3X1LaAjv+wNM3c9lmfIq0CGWB5DVVJ56BhICiqQ 9DOGV9TlY/Qo8YGSXIwcV2hJHY4TjuYaP3Fhc80Q6Oz6nkffdldmu7/DJJo0OmmGNiKk IX+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=BdxXWNWCwXyo34zuyi/62cZr4j0t4y4EbTTp2nD/nis=; b=qcqKM4DluTQEkw7eXI3YicZivvvged8myj2yRsZC0wIeAPIuP9lk648xdJ4/f702oo UV6XYaFDKX6WzS/KD7aMKpCtS1qfSK96Jl9s5kUg5zI2saDrD/BPaUf/eNB30tYVhb9f 63ZJCfYeNNWOQGqlSnT5/aGldaM92IMEGTlm7yv7aFCj/aL5JJzmPFxqCVrkDSEUA2UO Qr5aktvUqzWOpIm3RdCyN/P43czRWlhVd7+De5RzmPkx0cQpiIfIv/UGtbmwE/z5w4vo Qoq6O3KbzsmIxcI9fvi/ZvKokNZ7j+AvPD3RxkVWmfPvW3sCG/dncZxOzLucV6MVi7Mx qMwA== X-Gm-Message-State: AA+aEWaSTQpw2QTz9IFWDDjZ4pSxnWfrBqCkhNrbqKBtG0kbgKrHtJ67 tjdb/IMV53z7F06WeZh0kny6BD2x2B+LEQ== X-Google-Smtp-Source: ALg8bN7rpdBhFKOMZ23/wGoipb5SueQlwiWPSmoYoEcpKTArfUZikR3MH7Ie5/H8KKgx7KtdZdpzXg== X-Received: by 2002:ac8:2c79:: with SMTP id e54mr62957231qta.17.1546912390079; Mon, 07 Jan 2019 17:53:10 -0800 (PST) Received: from ovpn-120-55.rdu2.redhat.com (pool-71-184-117-43.bstnma.fios.verizon.net. [71.184.117.43]) by smtp.gmail.com with ESMTPSA id z30sm41882174qtz.26.2019.01.07.17.53.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 Jan 2019 17:53:09 -0800 (PST) Subject: Re: [PATCH v3] mm/page_owner: fix for deferred struct page init To: Michal Hocko Cc: akpm@linux-foundation.org, Pavel.Tatashin@microsoft.com, mingo@kernel.org, mgorman@techsingularity.net, iamjoonsoo.kim@lge.com, tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20190103190715.GZ31793@dhcp22.suse.cz> <62e96e34-7ea9-491a-b5b6-4828da980d48@lca.pw> <20190103202235.GE31793@dhcp22.suse.cz> <20190104130906.GO31793@dhcp22.suse.cz> <20190104151737.GT31793@dhcp22.suse.cz> <20190104153245.GV31793@dhcp22.suse.cz> <20190107184309.GM31793@dhcp22.suse.cz> From: Qian Cai Message-ID: Date: Mon, 7 Jan 2019 20:53:08 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.3.3 MIME-Version: 1.0 In-Reply-To: <20190107184309.GM31793@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/7/19 1:43 PM, Michal Hocko wrote: > On Fri 04-01-19 15:18:08, Qian Cai wrote: > [...] >> Though, I can't see any really benefit of this approach apart from "beautify" > > This is not about beautifying! This is about making the code long term > maintainable. As you can see it is just too easy to break it with the > current scheme. And that is bad especially when the code is broken > because of an optimization. > Understood, but the code is now fixed. If there is something fundamentally broken in the future, it may be a good time then to create a looks like hundred-line cleanup patch for long-term maintenance at the same time to fix real bugs.