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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no 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 E95F4C3F2CD for ; Wed, 4 Mar 2020 07:06:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AD0A5214D8 for ; Wed, 4 Mar 2020 07:06:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD0A5214D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3D74A6B0003; Wed, 4 Mar 2020 02:06:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 387CB6B0005; Wed, 4 Mar 2020 02:06:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 276496B0006; Wed, 4 Mar 2020 02:06:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0109.hostedemail.com [216.40.44.109]) by kanga.kvack.org (Postfix) with ESMTP id 0F11E6B0003 for ; Wed, 4 Mar 2020 02:06:57 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id BB7AF4995FD for ; Wed, 4 Mar 2020 07:06:56 +0000 (UTC) X-FDA: 76556797632.22.iron67_599faaa4b1650 X-HE-Tag: iron67_599faaa4b1650 X-Filterd-Recvd-Size: 2778 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Mar 2020 07:06:55 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04396;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0TrcsTun_1583305608; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TrcsTun_1583305608) by smtp.aliyun-inc.com(127.0.0.1); Wed, 04 Mar 2020 15:06:48 +0800 Subject: Re: [PATCH v9 07/20] mm/lru: introduce TestClearPageLRU To: Andrew Morton Cc: cgroups@vger.kernel.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com, Michal Hocko , Vladimir Davydov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Rong Chen References: <1583146830-169516-1-git-send-email-alex.shi@linux.alibaba.com> <1583146830-169516-8-git-send-email-alex.shi@linux.alibaba.com> <20200302141144.b30abe0d89306fd387e13a92@linux-foundation.org> <9cacdc21-9c1f-2a17-05cb-e9cf2959cef5@linux.alibaba.com> <20200303164659.b3a30ab9d68c9ed82299a29c@linux-foundation.org> From: Alex Shi Message-ID: <6d155f79-8ba2-b322-4e92-311e7be98f79@linux.alibaba.com> Date: Wed, 4 Mar 2020 15:06:48 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200303164659.b3a30ab9d68c9ed82299a29c@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =E5=9C=A8 2020/3/4 =E4=B8=8A=E5=8D=888:46, Andrew Morton =E5=86=99=E9=81=93= : >=20 > Well, any difference would be small and the numbers did get a bit > lower, albeit probably within the margin of error. >=20 > But you know, if someone were to send a patch which micro-optimized > some code by replacing 'TestClearXXX()' with `if PageXXX() > ClearPageXXX()', I would happily merge it! >=20 > Is this change essential to the overall patchset? If not, I'd be > inclined to skip it? >=20 Hi Andrew, Thanks a lot for comments! Yes, this patch is essential for all next. Consider the normal memory testing would focus on user page, that probaba= bly with PageLRU.=20 Fengguang's vm-scalibicase-small-allocs which used a lots vm_area_struct = slab, which may got some impact. 0day/Cheng Rong is working on the test. In my roughly te= sting, it may drop 5% on my 96threads/394GB machine. Thanks Alex