Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp3934059imu; Mon, 7 Jan 2019 12:12:00 -0800 (PST) X-Google-Smtp-Source: ALg8bN5cblTBHZqUaJzyCkyliixSAsozL69dyrHs1Oh5itg1rpMNgwFnpozEJFZomFl7LckGyhFK X-Received: by 2002:a17:902:bd0b:: with SMTP id p11mr63014693pls.259.1546891920541; Mon, 07 Jan 2019 12:12:00 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1546891920; cv=none; d=google.com; s=arc-20160816; b=dMnLPorNJ4XevF2ZNXdISGdET8MiGyk/K/Ig7A6wjalMNxxmyS6ADRRPeb6w7Mzd44 YRwmZ5kEjDjA36Ri6VDs0BAYQRdnpa3D3S4jLDXb1SN5fBEyiXMOGjTZUHo9HDb9MNVu 5uxNgXPYuUhsbeXPukeNuMiexhsZgu8htYvJnx6hD9KrofrWhFvH8vlZViUjn6xFXO++ vY7SFcUtZVJFp3PDfmMTNlMT+gDoMDR8AQtB5siN/08FqfYqUat+n4TG3vU1BJA0a/AW q/6UoY6VBeQkNbmjqnu7oWBxMhTLNBHGocsSKqVYSgNzCrxdP82CB9tb6YoEdtNYFWPN Z9Wg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=jk5jiSF4mapp/Xf1sfibk3z2pelWwIE5Z2QE7VDA2d8=; b=diwvyTlZJzqPl+yIozIB886UkP1ZD64FtfxsaWqF4Ct0C3W11/F00QZZtluFZ1wRzo y5zp8PcgJh6Yw/iKKR/5hG8z7L4H0HoMYo7h5PoPqt1aIfsPvS6xXJIky/hQFLMhqEiH yul0Y+B9gHoAGJbeoTvEfeJbThPh168SJ5XVD5G37bZaxRZuInoX5cA+vXLXiNbpRYx3 r5v3nwiJvO7mShIIV8B96SKQgZiIdyvxPXJdQs1Qudq6yeFrInPYqCcLq9h8LDN2xz1C CgV+pcM7bHlzJt6bLMAikFC80k4PY/qB5v6EqPTIeyloYYfaYnAbRRhgylyoEDLB/ICw DpgA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d19si9148065pfd.196.2019.01.07.12.11.45; Mon, 07 Jan 2019 12:12:00 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727049AbfAGSnM (ORCPT + 99 others); Mon, 7 Jan 2019 13:43:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:51974 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726718AbfAGSnM (ORCPT ); Mon, 7 Jan 2019 13:43:12 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id ED05FAEB2; Mon, 7 Jan 2019 18:43:10 +0000 (UTC) Date: Mon, 7 Jan 2019 19:43:09 +0100 From: Michal Hocko To: Qian Cai 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 Subject: Re: [PATCH v3] mm/page_owner: fix for deferred struct page init Message-ID: <20190107184309.GM31793@dhcp22.suse.cz> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- Michal Hocko SUSE Labs