From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id 848848E0038 for ; Tue, 8 Jan 2019 17:40:32 -0500 (EST) Received: by mail-ed1-f70.google.com with SMTP id x15so2183675edd.2 for ; Tue, 08 Jan 2019 14:40:32 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id t26si542292eds.246.2019.01.08.14.40.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 Jan 2019 14:40:31 -0800 (PST) Date: Tue, 8 Jan 2019 23:40:26 +0100 From: Michal Hocko Subject: Re: [PATCH v3] mm/page_owner: fix for deferred struct page init Message-ID: <20190108224026.GL31793@dhcp22.suse.cz> References: <20190104151737.GT31793@dhcp22.suse.cz> <20190104153245.GV31793@dhcp22.suse.cz> <20190107184309.GM31793@dhcp22.suse.cz> <20190108082032.GP31793@dhcp22.suse.cz> <1546953547.6911.1.camel@lca.pw> <20190108140253.5b6db0ab37334b845e9d4fc2@linux-foundation.org> 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: Andrew Morton , 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 Tue 08-01-19 17:13:41, Qian Cai wrote: > > > On 1/8/19 5:02 PM, Andrew Morton wrote: > > > > It's unclear (to me) where we stand with this patch. Shold we proceed > > with v3 for now, or is something else planned? > > I don't have anything else plan for this right now. Michal particular don't like > that 4-line ifdef which supposes to avoid an immediately regression (arguably > small) that existing page_owner users with DEFERRED_STRUCT_PAGE_INIT deselected > that would start to miss tens of thousands early page allocation call sites. So, > feel free to choose v2 of this which has no ifdef if you agree with Michal too. > I am fine either way. Yes I would prefer to revert the faulty commit (fe53ca54270) and work on a more robust page_owner initialization to cover earlier allocations on top of that. Not that I would insist but this would be a more straightforward approach and I hope it will result in a better long term maintainable code in the end. -- Michal Hocko SUSE Labs