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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY 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 2D3BAC43466 for ; Mon, 21 Sep 2020 01:57:43 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 979D1207BB for ; Mon, 21 Sep 2020 01:57:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 979D1207BB 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=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kKB4n-0006GM-T8; Mon, 21 Sep 2020 01:57:09 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kKB4n-0006GH-BY for xen-devel@lists.xenproject.org; Mon, 21 Sep 2020 01:57:09 +0000 X-Inumbo-ID: aa07bbea-6272-4a1a-9082-66a30a1df7b3 Received: from out30-132.freemail.mail.aliyun.com (unknown [115.124.30.132]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id aa07bbea-6272-4a1a-9082-66a30a1df7b3; Mon, 21 Sep 2020 01:57:06 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R391e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04426; MF=richard.weiyang@linux.alibaba.com; NM=1; PH=DS; RN=17; SR=0; TI=SMTPD_---0U9XKMRq_1600653420; Received: from localhost(mailfrom:richard.weiyang@linux.alibaba.com fp:SMTPD_---0U9XKMRq_1600653420) by smtp.aliyun-inc.com(127.0.0.1); Mon, 21 Sep 2020 09:57:01 +0800 Date: Mon, 21 Sep 2020 09:57:00 +0800 From: Wei Yang To: David Hildenbrand Cc: Wei Yang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, Andrew Morton , Alexander Duyck , Mel Gorman , Michal Hocko , Dave Hansen , Vlastimil Babka , Oscar Salvador , Mike Rapoport , Scott Cheloha , Michael Ellerman Subject: Re: [PATCH RFC 2/4] mm/page_alloc: place pages to tail in __putback_isolated_page() Message-ID: <20200921015700.GA83969@L-31X9LVDL-1304.local> References: <20200916183411.64756-1-david@redhat.com> <20200916183411.64756-3-david@redhat.com> <20200918020758.GB54754@L-31X9LVDL-1304.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Fri, Sep 18, 2020 at 09:27:23AM +0200, David Hildenbrand wrote: >On 18.09.20 04:07, Wei Yang wrote: >> On Wed, Sep 16, 2020 at 08:34:09PM +0200, David Hildenbrand wrote: >>> __putback_isolated_page() already documents that pages will be placed to >>> the tail of the freelist - this is, however, not the case for >>> "order >= MAX_ORDER - 2" (see buddy_merge_likely()) - which should be >>> the case for all existing users. >>> >>> This change affects two users: >>> - free page reporting >>> - page isolation, when undoing the isolation. >>> >>> This behavior is desireable for pages that haven't really been touched >>> lately, so exactly the two users that don't actually read/write page >>> content, but rather move untouched pages. >>> >>> The new behavior is especially desirable for memory onlining, where we >>> allow allocation of newly onlined pages via undo_isolate_page_range() >>> in online_pages(). Right now, we always place them to the head of the >> >> The code looks good, while I don't fully understand the log here. >> >> undo_isolate_page_range() is used in __offline_pages and alloc_contig_range. I >> don't connect them with online_pages(). Do I miss something? > >Yeah, please look at -mm / -next instead. See > >https://lkml.kernel.org/r/20200819175957.28465-11-david@redhat.com > Thanks, I get the point. > >-- >Thanks, > >David / dhildenb -- Wei Yang Help you, Help me