From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by kanga.kvack.org (Postfix) with ESMTP id 783AD8E0038 for ; Tue, 8 Jan 2019 03:20:37 -0500 (EST) Received: by mail-ed1-f69.google.com with SMTP id c34so1273371edb.8 for ; Tue, 08 Jan 2019 00:20:37 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id p12si2016387edq.284.2019.01.08.00.20.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 Jan 2019 00:20:36 -0800 (PST) Date: Tue, 8 Jan 2019 09:20:32 +0100 From: Michal Hocko Subject: Re: [PATCH v3] mm/page_owner: fix for deferred struct page init Message-ID: <20190108082032.GP31793@dhcp22.suse.cz> References: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: 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 On Mon 07-01-19 20:53:08, Qian Cai wrote: > > > 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. Yeah, so revert = fix and redisign the thing to make the code more robust longterm + allow to catch more allocation. I really fail to see why this has to be repeated several times in this thread. Really. -- Michal Hocko SUSE Labs