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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 9E4D1C10F14 for ; Thu, 3 Oct 2019 09:53:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3A406222C5 for ; Thu, 3 Oct 2019 09:53:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A406222C5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7FAC56B0005; Thu, 3 Oct 2019 05:53:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 780106B0006; Thu, 3 Oct 2019 05:53:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 694E58E0003; Thu, 3 Oct 2019 05:53:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0149.hostedemail.com [216.40.44.149]) by kanga.kvack.org (Postfix) with ESMTP id 4937E6B0005 for ; Thu, 3 Oct 2019 05:53:01 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id D556325704 for ; Thu, 3 Oct 2019 09:53:00 +0000 (UTC) X-FDA: 76002009720.08.slip73_37618ca876a11 X-HE-Tag: slip73_37618ca876a11 X-Filterd-Recvd-Size: 2885 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Oct 2019 09:53:00 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5B9D91000; Thu, 3 Oct 2019 02:52:59 -0700 (PDT) Received: from [10.162.40.180] (p8cg001049571a15.blr.arm.com [10.162.40.180]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 84E9F3F739; Thu, 3 Oct 2019 02:52:56 -0700 (PDT) Subject: Re: [PATCH] mm/page_alloc: Add a reason for reserved pages in has_unmovable_pages() To: Qian Cai Cc: linux-mm@kvack.org, Andrew Morton , Michal Hocko , Vlastimil Babka , Oscar Salvador , Mel Gorman , Mike Rapoport , Dan Williams , Pavel Tatashin , linux-kernel@vger.kernel.org References: <1570090257-25001-1-git-send-email-anshuman.khandual@arm.com> <7FA7CBE1-E0A9-40E2-B3CA-0896F6D491E5@lca.pw> <37b43978-5652-576c-8990-451e751b7c67@arm.com> From: Anshuman Khandual Message-ID: Date: Thu, 3 Oct 2019 15:23:18 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <37b43978-5652-576c-8990-451e751b7c67@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.013333, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 10/03/2019 03:02 PM, Anshuman Khandual wrote: >=20 > On 10/03/2019 02:35 PM, Qian Cai wrote: >> >>> On Oct 3, 2019, at 4:10 AM, Anshuman Khandual wrote: >>> >>> Having unmovable pages on a given pageblock should be reported correc= tly >>> when required with REPORT_FAILURE flag. But there can be a scenario w= here a >>> reserved page in the page block will get reported as a generic "unmov= able" >>> reason code. Instead this should be changed to a more appropriate rea= son >>> code like "Reserved page". >> Isn=E2=80=99t this redundant as it dumps the flags in dump_page() anyw= ay? > Even though page flags does contain reserved bit information, the probl= em > is that we are explicitly printing the reason for this page dump. In th= is > case it is caused by the fact that it is a reserved page. >=20 > page dumped because: >=20 > The proposed change makes it explicit that the dump is caused because a > non movable page with reserved bit set. It also helps in differentiatin= g=20 > between reserved bit condition and the last one "if (found > count)" Instead, will it better to rename the reason codes as 1. "Unmovable (CMA)" 2. "Unmovable (Reserved)" 3. "Unmovable (Private/non-LRU)"