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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 ABFE8C10F14 for ; Thu, 3 Oct 2019 16:48:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 68D1C20867 for ; Thu, 3 Oct 2019 16:48:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68D1C20867 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EAC356B0005; Thu, 3 Oct 2019 12:48:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E36056B0006; Thu, 3 Oct 2019 12:48:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CFC2D6B0007; Thu, 3 Oct 2019 12:48:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0054.hostedemail.com [216.40.44.54]) by kanga.kvack.org (Postfix) with ESMTP id A8B126B0005 for ; Thu, 3 Oct 2019 12:48:29 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 4B8E2181AC9AE for ; Thu, 3 Oct 2019 16:48:29 +0000 (UTC) X-FDA: 76003056738.23.grape59_2ce9b2bac614c X-HE-Tag: grape59_2ce9b2bac614c X-Filterd-Recvd-Size: 8240 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Oct 2019 16:48:28 +0000 (UTC) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x93GkLBj076306; Thu, 3 Oct 2019 12:48:20 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2vdm7ksfkn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Oct 2019 12:48:19 -0400 Received: from m0098394.ppops.net (m0098394.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x93GkUCH077867; Thu, 3 Oct 2019 12:48:19 -0400 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0a-001b2d01.pphosted.com with ESMTP id 2vdm7ksfjy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Oct 2019 12:48:19 -0400 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x93GlTUY018767; Thu, 3 Oct 2019 16:48:18 GMT Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by ppma02dal.us.ibm.com with ESMTP id 2v9y589719-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 03 Oct 2019 16:48:17 +0000 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x93GmGHr44695846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 3 Oct 2019 16:48:16 GMT Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 999B06A05D; Thu, 3 Oct 2019 16:48:16 +0000 (GMT) Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 011646A047; Thu, 3 Oct 2019 16:48:11 +0000 (GMT) Received: from [9.199.43.217] (unknown [9.199.43.217]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 3 Oct 2019 16:48:11 +0000 (GMT) Subject: Re: [PATCH v5 01/10] mm/memunmap: Use the correct start and end pfn when removing pages from zone To: David Hildenbrand , linux-kernel@vger.kernel.org, Dan Williams Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, Andrew Morton , Jason Gunthorpe , Logan Gunthorpe , Ira Weiny , Pankaj Gupta References: <20191001144011.3801-1-david@redhat.com> <20191001144011.3801-2-david@redhat.com> <933f9cd8-9a32-8566-bd97-7e475a009275@redhat.com> <09b61ab1-6099-d825-8e04-fbfb43abe4d2@redhat.com> From: "Aneesh Kumar K.V" Message-ID: Date: Thu, 3 Oct 2019 22:18:10 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <09b61ab1-6099-d825-8e04-fbfb43abe4d2@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-10-03_07:,, 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=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910030146 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 10/1/19 8:33 PM, David Hildenbrand wrote: > On 01.10.19 16:57, David Hildenbrand wrote: >> On 01.10.19 16:40, David Hildenbrand wrote: >>> From: "Aneesh Kumar K.V" >>> >>> With altmap, all the resource pfns are not initialized. While initializing >>> pfn, altmap reserve space is skipped. Hence when removing pfn from zone >>> skip pfns that were never initialized. >>> >>> Update memunmap_pages to calculate start and end pfn based on altmap >>> values. This fixes a kernel crash that is observed when destroying >>> a namespace. >>> >>> [ 81.356173] kernel BUG at include/linux/mm.h:1107! >>> cpu 0x1: Vector: 700 (Program Check) at [c000000274087890] >>> pc: c0000000004b9728: memunmap_pages+0x238/0x340 >>> lr: c0000000004b9724: memunmap_pages+0x234/0x340 >>> ... >>> pid = 3669, comm = ndctl >>> kernel BUG at include/linux/mm.h:1107! >>> [c000000274087ba0] c0000000009e3500 devm_action_release+0x30/0x50 >>> [c000000274087bc0] c0000000009e4758 release_nodes+0x268/0x2d0 >>> [c000000274087c30] c0000000009dd144 device_release_driver_internal+0x174/0x240 >>> [c000000274087c70] c0000000009d9dfc unbind_store+0x13c/0x190 >>> [c000000274087cb0] c0000000009d8a24 drv_attr_store+0x44/0x60 >>> [c000000274087cd0] c0000000005a7470 sysfs_kf_write+0x70/0xa0 >>> [c000000274087d10] c0000000005a5cac kernfs_fop_write+0x1ac/0x290 >>> [c000000274087d60] c0000000004be45c __vfs_write+0x3c/0x70 >>> [c000000274087d80] c0000000004c26e4 vfs_write+0xe4/0x200 >>> [c000000274087dd0] c0000000004c2a6c ksys_write+0x7c/0x140 >>> [c000000274087e20] c00000000000bbd0 system_call+0x5c/0x68 >>> >>> Cc: Dan Williams >>> Cc: Andrew Morton >>> Cc: Jason Gunthorpe >>> Cc: Logan Gunthorpe >>> Cc: Ira Weiny >>> Reviewed-by: Pankaj Gupta >>> Signed-off-by: Aneesh Kumar K.V >>> [ move all pfn-realted declarations into a single line ] >>> Signed-off-by: David Hildenbrand >>> --- >>> mm/memremap.c | 13 ++++++++----- >>> 1 file changed, 8 insertions(+), 5 deletions(-) >>> >>> diff --git a/mm/memremap.c b/mm/memremap.c >>> index 557e53c6fb46..026788b2ac69 100644 >>> --- a/mm/memremap.c >>> +++ b/mm/memremap.c >>> @@ -123,7 +123,7 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) >>> void memunmap_pages(struct dev_pagemap *pgmap) >>> { >>> struct resource *res = &pgmap->res; >>> - unsigned long pfn; >>> + unsigned long pfn, nr_pages, start_pfn, end_pfn; >>> int nid; >>> >>> dev_pagemap_kill(pgmap); >>> @@ -131,14 +131,17 @@ void memunmap_pages(struct dev_pagemap *pgmap) >>> put_page(pfn_to_page(pfn)); >>> dev_pagemap_cleanup(pgmap); >>> >>> + start_pfn = pfn_first(pgmap); >>> + end_pfn = pfn_end(pgmap); >>> + nr_pages = end_pfn - start_pfn; >>> + >>> /* pages are dead and unused, undo the arch mapping */ >>> - nid = page_to_nid(pfn_to_page(PHYS_PFN(res->start))); >>> + nid = page_to_nid(pfn_to_page(start_pfn)); >>> >>> mem_hotplug_begin(); >>> if (pgmap->type == MEMORY_DEVICE_PRIVATE) { >>> - pfn = PHYS_PFN(res->start); >>> - __remove_pages(page_zone(pfn_to_page(pfn)), pfn, >>> - PHYS_PFN(resource_size(res)), NULL); >>> + __remove_pages(page_zone(pfn_to_page(start_pfn)), start_pfn, >>> + nr_pages, NULL); >>> } else { >>> arch_remove_memory(nid, res->start, resource_size(res), >>> pgmap_altmap(pgmap)); >>> >> >> Aneesh, I was wondering why the use of "res->start" is correct (and we >> shouldn't also witch to start_pfn/nr_pages here. It would be good if Dan >> could review. >> > > To be more precise, I wonder if it should actually be > > __remove_pages(page_zone(pfn_to_page(start_pfn)), res->start, > resource_size(res)) > yes, that would be make it much clear. But for MEMORY_DEVICE_PRIVATE start_pfn and pfn should be same? > IOW, keep calling __remove_pages() with the same parameters but read > nid/zone from the offset one. > > Hope some memunmap_pages() expert can clarify. > -aneesh