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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 9D6CFC04EB8 for ; Thu, 6 Dec 2018 05:22:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68A2C20989 for ; Thu, 6 Dec 2018 05:22:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68A2C20989 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ah.jp.nec.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729021AbeLFFWn convert rfc822-to-8bit (ORCPT ); Thu, 6 Dec 2018 00:22:43 -0500 Received: from tyo161.gate.nec.co.jp ([114.179.232.161]:48137 "EHLO tyo161.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728489AbeLFFWn (ORCPT ); Thu, 6 Dec 2018 00:22:43 -0500 Received: from mailgate01.nec.co.jp ([114.179.233.122]) by tyo161.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id wB65MPNd002833 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 6 Dec 2018 14:22:25 +0900 Received: from mailsv02.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate01.nec.co.jp (8.15.1/8.15.1) with ESMTP id wB65MP2i006101; Thu, 6 Dec 2018 14:22:25 +0900 Received: from mail03.kamome.nec.co.jp (mail03.kamome.nec.co.jp [10.25.43.7]) by mailsv02.nec.co.jp (8.15.1/8.15.1) with ESMTP id wB65KqZi027049; Thu, 6 Dec 2018 14:22:25 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.150] [10.38.151.150]) by mail02.kamome.nec.co.jp with ESMTP id BT-MMP-393006; Thu, 6 Dec 2018 14:21:39 +0900 Received: from BPXM23GP.gisp.nec.co.jp ([10.38.151.215]) by BPXC22GP.gisp.nec.co.jp ([10.38.151.150]) with mapi id 14.03.0319.002; Thu, 6 Dec 2018 14:21:38 +0900 From: Naoya Horiguchi To: Michal Hocko CC: Oscar Salvador , Andrew Morton , Dan Williams , "Pavel Tatashin" , "linux-mm@kvack.org" , LKML , Stable tree Subject: Re: [RFC PATCH] hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined Thread-Topic: [RFC PATCH] hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined Thread-Index: AQHUiu9tY5+24nB+PkGyMm7atS1YiqVvf4kAgABK3wCAAM/4gA== Date: Thu, 6 Dec 2018 05:21:38 +0000 Message-ID: <20181206052137.GA28595@hori1.linux.bs1.fc.nec.co.jp> References: <20181203100309.14784-1-mhocko@kernel.org> <20181205122918.GL1286@dhcp22.suse.cz> <20181205165716.GS1286@dhcp22.suse.cz> In-Reply-To: <20181205165716.GS1286@dhcp22.suse.cz> Accept-Language: en-US, ja-JP Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.51.8.82] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 05, 2018 at 05:57:16PM +0100, Michal Hocko wrote: > On Wed 05-12-18 13:29:18, Michal Hocko wrote: > [...] > > After some more thinking I am not really sure the above reasoning is > > still true with the current upstream kernel. Maybe I just managed to > > confuse myself so please hold off on this patch for now. Testing by > > Oscar has shown this patch is helping but the changelog might need to be > > updated. > > OK, so Oscar has nailed it down and it seems that 4.4 kernel we have > been debugging on behaves slightly different. The underlying problem is > the same though. So I have reworded the changelog and added "just in > case" PageLRU handling. Naoya, maybe you have an argument that would > make this void for current upstream kernels. The following commit (not in 4.4.x stable tree) might explain the difference you experienced: commit 286c469a988fbaf68e3a97ddf1e6c245c1446968 Author: Naoya Horiguchi Date: Wed May 3 14:56:22 2017 -0700 mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page This commit adds shake_page() for mlocked pages to make sure that the target page is flushed out from LRU cache. Without this shake_page(), subsequent delete_from_lru_cache() (from me_pagecache_clean()) fails to isolate it and the page will finally return back to LRU list. So this scenario leads to "hwpoisoned by still linked to LRU list" page. Thanks, Naoya Horiguchi