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 53E60C04EB8 for ; Thu, 6 Dec 2018 08:40:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2527F2082D for ; Thu, 6 Dec 2018 08:40:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2527F2082D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de 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 S1729173AbeLFIk0 (ORCPT ); Thu, 6 Dec 2018 03:40:26 -0500 Received: from mx2.suse.de ([195.135.220.15]:46484 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727832AbeLFIkZ (ORCPT ); Thu, 6 Dec 2018 03:40:25 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id EBDCAADE6; Thu, 6 Dec 2018 08:40:23 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 06 Dec 2018 09:40:23 +0100 From: osalvador@suse.de To: Michal Hocko Cc: Naoya Horiguchi , Oscar Salvador , Andrew Morton , Dan Williams , Pavel Tatashin , linux-mm@kvack.org, LKML , Stable tree , owner-linux-mm@kvack.org Subject: Re: [RFC PATCH] hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined In-Reply-To: <20181206083206.GC1286@dhcp22.suse.cz> References: <20181203100309.14784-1-mhocko@kernel.org> <20181205122918.GL1286@dhcp22.suse.cz> <20181205165716.GS1286@dhcp22.suse.cz> <20181206052137.GA28595@hori1.linux.bs1.fc.nec.co.jp> <20181206083206.GC1286@dhcp22.suse.cz> Message-ID: X-Sender: osalvador@suse.de User-Agent: Roundcube Webmail Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> 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. > > OK, I see. So does that mean that the LRU handling is no longer needed > and there is a guanratee that all kernels with the above commit cannot > ever get an LRU page? For the sake of completeness: I made a quick test reverting 286c469a988 on upstream kernel. As expected, the poisoned page is in LRU when it hits do_migrate_range, and so, the migration path is taken and I see the exact failure I saw on. 4.4 Oscar Salvador --- Suse L3