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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 6163FECE58E for ; Thu, 17 Oct 2019 18:28:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C44021D7A for ; Thu, 17 Oct 2019 18:28:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571336885; bh=rEDLEagXBTtzsGBjtzn4+e2KUWhpjZWZsWl2gW7slRQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=jCSbO2QFzNhNtYm9xIlLQBhjLR34bKVyTPuTmhpHfkVYOwGGHaAxx1fEAZeo1Eg9y gZ6+T4hZR3gIJhb6u4TaJZYJ24wDdSrgrdXmEnZNGoF860YnFxfZxLaz2GbrGhwBtx PbpJ8e7TtbgjzJUBZ60l8n68H0RaTz5ypeD0/oPU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390662AbfJQS2D (ORCPT ); Thu, 17 Oct 2019 14:28:03 -0400 Received: from mx2.suse.de ([195.135.220.15]:42866 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727235AbfJQS2D (ORCPT ); Thu, 17 Oct 2019 14:28:03 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E878FB47D; Thu, 17 Oct 2019 18:28:01 +0000 (UTC) Date: Thu, 17 Oct 2019 20:27:59 +0200 From: Michal Hocko To: Naoya Horiguchi Cc: Qian Cai , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , David Hildenbrand , Mike Kravetz Subject: Re: memory offline infinite loop after soft offline Message-ID: <20191017182759.GN24485@dhcp22.suse.cz> References: <1570829564.5937.36.camel@lca.pw> <20191014083914.GA317@dhcp22.suse.cz> <20191017093410.GA19973@hori.linux.bs1.fc.nec.co.jp> <20191017100106.GF24485@dhcp22.suse.cz> <1571335633.5937.69.camel@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1571335633.5937.69.camel@lca.pw> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 17-10-19 14:07:13, Qian Cai wrote: > On Thu, 2019-10-17 at 12:01 +0200, Michal Hocko wrote: > > On Thu 17-10-19 09:34:10, Naoya Horiguchi wrote: > > > On Mon, Oct 14, 2019 at 10:39:14AM +0200, Michal Hocko wrote: > > > > [...] > > > > diff --git a/mm/page_isolation.c b/mm/page_isolation.c > > > > index 89c19c0feadb..5fb3fee16fde 100644 > > > > --- a/mm/page_isolation.c > > > > +++ b/mm/page_isolation.c > > > > @@ -274,7 +274,7 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn, > > > > * simple way to verify that as VM_BUG_ON(), though. > > > > */ > > > > pfn += 1 << page_order(page); > > > > - else if (skip_hwpoisoned_pages && PageHWPoison(page)) > > > > + else if (skip_hwpoisoned_pages && PageHWPoison(compound_head(page))) > > > > /* A HWPoisoned page cannot be also PageBuddy */ > > > > pfn++; > > > > else > > > > > > This fix looks good to me. The original code only addresses hwpoisoned 4kB-page, > > > we seem to have this issue since the following commit, > > > > Thanks a lot for double checking Naoya! > > > > > commit b023f46813cde6e3b8a8c24f432ff9c1fd8e9a64 > > > Author: Wen Congyang > > > Date: Tue Dec 11 16:00:45 2012 -0800 > > > > > > memory-hotplug: skip HWPoisoned page when offlining pages > > > > > > and extension of LTP coverage finally discovered this. > > > > Qian, could you give the patch some testing? > > Unfortunately, this does not solve the problem. It looks to me that in > soft_offline_huge_page(), set_hwpoison_free_buddy_page() will only set > PG_hwpoison for buddy pages, so the even the compound_head() has no PG_hwpoison > set. > > if (PageBuddy(page_head) && page_order(page_head) >= order) { > if (!TestSetPageHWPoison(page)) > hwpoisoned = true; This is more than unexpected. How are we supposed to find out that the page is poisoned? Any idea Naoya? -- Michal Hocko SUSE Labs