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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 43896C433E0 for ; Sun, 19 Jul 2020 03:59:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0D3F0207DA for ; Sun, 19 Jul 2020 03:59:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D3F0207DA 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 8DB9F6B0003; Sat, 18 Jul 2020 23:59:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 88B716B0005; Sat, 18 Jul 2020 23:59:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A1B26B0006; Sat, 18 Jul 2020 23:59:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0227.hostedemail.com [216.40.44.227]) by kanga.kvack.org (Postfix) with ESMTP id 67D066B0003 for ; Sat, 18 Jul 2020 23:59:48 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id EDF074DAD for ; Sun, 19 Jul 2020 03:59:47 +0000 (UTC) X-FDA: 77053471614.06.field40_14039f326f19 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin06.hostedemail.com (Postfix) with ESMTP id AD701100431CD for ; Sun, 19 Jul 2020 03:59:47 +0000 (UTC) X-HE-Tag: field40_14039f326f19 X-Filterd-Recvd-Size: 3353 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Sun, 19 Jul 2020 03:59:44 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07484;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0U36eCsi_1595131176; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U36eCsi_1595131176) by smtp.aliyun-inc.com(127.0.0.1); Sun, 19 Jul 2020 11:59:37 +0800 Subject: Re: [PATCH v16 15/22] mm/compaction: do page isolation first in compaction To: Alexander Duyck Cc: Andrew Morton , Mel Gorman , Tejun Heo , Hugh Dickins , Konstantin Khlebnikov , Daniel Jordan , Yang Shi , Matthew Wilcox , Johannes Weiner , kbuild test robot , linux-mm , LKML , cgroups@vger.kernel.org, Shakeel Butt , Joonsoo Kim , Wei Yang , "Kirill A. Shutemov" References: <1594429136-20002-1-git-send-email-alex.shi@linux.alibaba.com> <1594429136-20002-16-git-send-email-alex.shi@linux.alibaba.com> From: Alex Shi Message-ID: Date: Sun, 19 Jul 2020 11:59:36 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 X-Rspamd-Queue-Id: AD701100431CD X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 2020/7/18 =E4=B8=8A=E5=8D=8812:09, Alexander Duyck =E5=86=99=E9= =81=93: >>> I wonder if it wouldn't make sense to combine these two atomic ops >>> with tests and the put_page into a single inline function? Then it >>> could be possible to just do one check and if succeeds you do the >>> block of code below, otherwise you just fall-through into the -EBUSY >>> case. >>> >> Uh, since get_page changes page->_refcount, TestClearPageLRU changes p= age->flags, >> So I don't know how to combine them, could you make it more clear with= code? > Actually it is pretty straight forward. Something like this: > static inline bool get_page_unless_zero_or_nonlru(struct page *page) > { > if (get_page_unless_zero(page)) { > if (TestClearPageLRU(page)) > return true; > put_page(page); > } > return false; > } >=20 > You can then add comments as necessary. The general idea is you are > having to do this in two different spots anyway so why not combine the > logic? Although it does assume you can change the ordering of the > other test above. It doesn't look different with original code, does it? Thanks Alex