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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 20F8DC43381 for ; Mon, 18 Feb 2019 14:06:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E41AD21916 for ; Mon, 18 Feb 2019 14:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390364AbfBROGT (ORCPT ); Mon, 18 Feb 2019 09:06:19 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:56630 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390313AbfBROGJ (ORCPT ); Mon, 18 Feb 2019 09:06:09 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1IE5sP4023723 for ; Mon, 18 Feb 2019 09:06:08 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qqves5hb5-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 18 Feb 2019 09:06:00 -0500 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Feb 2019 14:05:23 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (9.149.109.196) by e06smtp04.uk.ibm.com (192.168.101.134) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 18 Feb 2019 14:05:20 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1IE5JPa11468970 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 18 Feb 2019 14:05:19 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ED46352057; Mon, 18 Feb 2019 14:05:18 +0000 (GMT) Received: from rapoport-lnx (unknown [9.148.207.239]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id CFC495204E; Mon, 18 Feb 2019 14:05:17 +0000 (GMT) Date: Mon, 18 Feb 2019 16:05:15 +0200 From: Mike Rapoport To: Michal Hocko Cc: Rong Chen , Pavel Tatashin , linux-kernel@vger.kernel.org, Linux Memory Management List , Andrew Morton , LKP , Oscar Salvador Subject: Re: [LKP] efad4e475c [ 40.308255] Oops: 0000 [#1] PREEMPT SMP PTI References: <20190218052823.GH29177@shao2-debian> <20190218070844.GC4525@dhcp22.suse.cz> <20190218085510.GC7251@dhcp22.suse.cz> <4c75d424-2c51-0d7d-5c28-78c15600e93c@intel.com> <20190218103013.GK4525@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190218103013.GK4525@dhcp22.suse.cz> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 19021814-0016-0000-0000-00000257CD78 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19021814-0017-0000-0000-000032B20D41 Message-Id: <20190218140515.GF25446@rapoport-lnx> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-18_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902180106 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 18, 2019 at 11:30:13AM +0100, Michal Hocko wrote: > On Mon 18-02-19 18:01:39, Rong Chen wrote: > > > > On 2/18/19 4:55 PM, Michal Hocko wrote: > > > [Sorry for an excessive quoting in the previous email] > > > [Cc Pavel - the full report is http://lkml.kernel.org/r/20190218052823.GH29177@shao2-debian[] > > > > > > On Mon 18-02-19 08:08:44, Michal Hocko wrote: > > > > On Mon 18-02-19 13:28:23, kernel test robot wrote: > > > [...] > > > > > [ 40.305212] PGD 0 P4D 0 > > > > > [ 40.308255] Oops: 0000 [#1] PREEMPT SMP PTI > > > > > [ 40.313055] CPU: 1 PID: 239 Comm: udevd Not tainted 5.0.0-rc4-00149-gefad4e4 #1 > > > > > [ 40.321348] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > > > > > [ 40.330813] RIP: 0010:page_mapping+0x12/0x80 > > > > > [ 40.335709] Code: 5d c3 48 89 df e8 0e ad 02 00 85 c0 75 da 89 e8 5b 5d c3 0f 1f 44 00 00 53 48 89 fb 48 8b 43 08 48 8d 50 ff a8 01 48 0f 45 da <48> 8b 53 08 48 8d 42 ff 83 e2 01 48 0f 44 c3 48 83 38 ff 74 2f 48 > > > > > [ 40.356704] RSP: 0018:ffff88801fa87cd8 EFLAGS: 00010202 > > > > > [ 40.362714] RAX: ffffffffffffffff RBX: fffffffffffffffe RCX: 000000000000000a > > > > > [ 40.370798] RDX: fffffffffffffffe RSI: ffffffff820b9a20 RDI: ffff88801e5c0000 > > > > > [ 40.378830] RBP: 6db6db6db6db6db7 R08: ffff88801e8bb000 R09: 0000000001b64d13 > > > > > [ 40.386902] R10: ffff88801fa87cf8 R11: 0000000000000001 R12: ffff88801e640000 > > > > > [ 40.395033] R13: ffffffff820b9a20 R14: ffff88801f145258 R15: 0000000000000001 > > > > > [ 40.403138] FS: 00007fb2079817c0(0000) GS:ffff88801dd00000(0000) knlGS:0000000000000000 > > > > > [ 40.412243] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > [ 40.418846] CR2: 0000000000000006 CR3: 000000001fa82000 CR4: 00000000000006a0 > > > > > [ 40.426951] Call Trace: > > > > > [ 40.429843] __dump_page+0x14/0x2c0 > > > > > [ 40.433947] is_mem_section_removable+0x24c/0x2c0 > > > > This looks like we are stumbling over an unitialized struct page again. > > > > Something this patch should prevent from. Could you try to apply [1] > > > > which will make __dump_page more robust so that we do not blow up there > > > > and give some more details in return. > > > > > > > > Btw. is this reproducible all the time? > > > And forgot to ask whether this is reproducible with pending mmotm > > > patches in linux-next. > > > > > > Do you mean the below patch? I can reproduce the problem too. > > Yes, thanks for the swift response. The patch has just added a debugging > output > [ 0.013697] Early memory node ranges > [ 0.013701] node 0: [mem 0x0000000000001000-0x000000000009efff] > [ 0.013706] node 0: [mem 0x0000000000100000-0x000000001ffdffff] > [ 0.013711] zeroying 0-1 > > This is the first pfn. > > [ 0.013715] zeroying 9f-100 > > this is [mem 0x9f000, 0xfffff] so it fills up the whole hole between the > above two ranges. This is definitely good. > > [ 0.013722] zeroying 1ffe0-1ffe0 > > this is a single page at 0x1ffe0000 right after the zone end. > > [ 0.013727] Zeroed struct page in unavailable ranges: 98 pages > > Hmm, so this is getting really interesting. The whole zone range should > be covered. So this is either some off-by-one or I something that I am > missing right now. Could you apply the following on top please? We > definitely need to see what pfn this is. > > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 124e794867c5..59bcfd934e37 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1232,12 +1232,14 @@ static bool is_pageblock_removable_nolock(struct page *page) > /* Checks if this range of memory is likely to be hot-removable. */ > bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) > { > - struct page *page = pfn_to_page(start_pfn); > + struct page *page = pfn_to_page(start_pfn), *first_page; > unsigned long end_pfn = min(start_pfn + nr_pages, zone_end_pfn(page_zone(page))); > struct page *end_page = pfn_to_page(end_pfn); > > /* Check the starting page of each pageblock within the range */ > - for (; page < end_page; page = next_active_pageblock(page)) { > + for (first_page = page; page < end_page; page = next_active_pageblock(page)) { > + if (PagePoisoned(page)) > + pr_info("Unexpected poisoned page %px pfn:%lx\n", page, start_pfn + page-first_page); > if (!is_pageblock_removable_nolock(page)) > return false; > cond_resched(); I've added more prints and somehow end_page gets too big (in brackets is the pfn): [ 11.183835] ===> start: ffff88801e240000(0), end: ffff88801e400000(8000) [ 11.188457] ===> start: ffff88801e400000(8000), end: ffff88801e640000(10000) [ 11.193266] ===> start: ffff88801e640000(10000), end: ffff88801e060000(18000) should be ffff88801e5c0000 [ 11.197363] ===> start: ffff88801e060000(18000), end: ffff88801e21f900(1ffe0) [ 11.207547] Unexpected poisoned page ffff88801e5c0000 pfn:10000 With the patch below the problem seem to disappear, although I have no idea why... diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 91e6fef..53d15ff 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1234,7 +1234,7 @@ bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) { struct page *page = pfn_to_page(start_pfn); unsigned long end_pfn = min(start_pfn + nr_pages, zone_end_pfn(page_zone(page))); - struct page *end_page = pfn_to_page(end_pfn); + struct page *end_page = page + (end_pfn - start_pfn); /* Check the starting page of each pageblock within the range */ for (; page < end_page; page = next_active_pageblock(page)) { > -- > Michal Hocko > SUSE Labs > -- Sincerely yours, Mike.