From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752483AbdJCPRV (ORCPT ); Tue, 3 Oct 2017 11:17:21 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:32098 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752129AbdJCPRS (ORCPT ); Tue, 3 Oct 2017 11:17:18 -0400 Subject: Re: [PATCH v9 03/12] mm: deferred_init_memmap improvements To: Michal Hocko Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, ard.biesheuvel@linaro.org, mark.rutland@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net, steven.sistare@oracle.com, daniel.m.jordan@oracle.com, bob.picco@oracle.com References: <20170920201714.19817-1-pasha.tatashin@oracle.com> <20170920201714.19817-4-pasha.tatashin@oracle.com> <20171003125754.2kuqzkstywg7axhd@dhcp22.suse.cz> From: Pasha Tatashin Message-ID: Date: Tue, 3 Oct 2017 11:15:54 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171003125754.2kuqzkstywg7axhd@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michal, > > Please be explicit that this is possible only because we discard > memblock data later after 3010f876500f ("mm: discard memblock data > later"). Also be more explicit how the new code works. OK > > I like how the resulting code is more compact and smaller. That was the goal :) > for_each_free_mem_range also looks more appropriate but I really detest > the DEFERRED_FREE thingy. Maybe we can handle all that in a single goto > section. I know this is not an art but manipulating variables from > macros is more error prone and much more ugly IMHO. Sure, I can re-arrange to have a goto place. Function won't be as small, and if compiler is not smart enough we might end up with having more branches than what my current code has. > > please do not use macros. Btw. this deserves its own fix. I suspect that > no CONFIG_HOLES_IN_ZONE arch enables DEFERRED_STRUCT_PAGE_INIT but > purely from the review point of view it should be its own patch. Sure, I will submit this patch separately from the rest of the project. In my opinion DEFERRED_STRUCT_PAGE_INIT is the way of the future, so we should make sure it is working with as many configs as possible. Thank you, Pasha