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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 E1870C43461 for ; Tue, 15 Sep 2020 09:42:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80A5121974 for ; Tue, 15 Sep 2020 09:42:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="iyboDCyT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbgIOJmQ (ORCPT ); Tue, 15 Sep 2020 05:42:16 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45592 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726304AbgIOJmG (ORCPT ); Tue, 15 Sep 2020 05:42:06 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08F9XWVj061799; Tue, 15 Sep 2020 05:41:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=pp1; bh=aPqDqlTqJKSwu68oJ1fpIKqH4hWMzeu2sogAm75s9/o=; b=iyboDCyToCvtxHxLNL095R5a7H+vCbcta3bENgWcaRXh1k0VZ7LUxikto1eQeBOHylPm MIewbVSXPig+f34N7CfcKYEJ3s6FbSkMgRcLLLY33vkcNFuccwDyIPF6VI2tZLqCrCF5 bIzLvvp98Ezm8HosqofrPO8h9y8d5+oX1Qt7KjnUOSUo0hR/U/+G4uWGYQuqo4ObOTjR 72Uu+PKGjFRoMMQ+qDmqTzO+tSvLOdghq9y/CgsJhzP+A7HKW35UWTkYQSSXUIbuv7Ws hpKvYgYgqbBMtCrxS+W7dr4gGpuiB/7kphKr5D3GoKv0wvZv5xRuzkIgeSS4fpLJcsbT 2g== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 33jr6bdmgk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 15 Sep 2020 05:41:52 -0400 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 08F9aZUM070503; Tue, 15 Sep 2020 05:41:51 -0400 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 33jr6bdmft-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 15 Sep 2020 05:41:51 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 08F9WLJ9030796; Tue, 15 Sep 2020 09:41:49 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma03ams.nl.ibm.com with ESMTP id 33gny8be6q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 15 Sep 2020 09:41:49 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 08F9eCEF28770676 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Sep 2020 09:40:12 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2B20FA4055; Tue, 15 Sep 2020 09:41:46 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A9516A4057; Tue, 15 Sep 2020 09:41:45 +0000 (GMT) Received: from pomme.tlslab.ibm.com (unknown [9.145.72.89]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 15 Sep 2020 09:41:45 +0000 (GMT) From: Laurent Dufour To: akpm@linux-foundation.org, David Hildenbrand , Oscar Salvador , mhocko@suse.com, Greg Kroah-Hartman Cc: linux-mm@kvack.org, "Rafael J . Wysocki" , nathanl@linux.ibm.com, cheloha@linux.ibm.com, Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v3 2/3] mm: don't rely on system state to detect hot-plug operations Date: Tue, 15 Sep 2020 11:41:42 +0200 Message-Id: <20200915094143.79181-3-ldufour@linux.ibm.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200915094143.79181-1-ldufour@linux.ibm.com> References: <20200915094143.79181-1-ldufour@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-15_05:2020-09-15,2020-09-15 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 phishscore=0 mlxlogscore=999 spamscore=0 lowpriorityscore=0 suspectscore=0 mlxscore=0 malwarescore=0 clxscore=1015 adultscore=0 bulkscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009150087 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In register_mem_sect_under_node() the system_state’s value is checked to detect whether the call is made during boot time or during an hot-plug operation. Unfortunately, that check against SYSTEM_BOOTING is wrong because regular memory is registered at SYSTEM_SCHEDULING state. In addition, memory hot-plug operation can be triggered at this system state by the ACPI [1]. So checking against the system state is not enough. The consequence is that on system with interleaved node's ranges like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] This can be seen on PowerPC LPAR after multiple memory hot-plug and hot-unplug operations are done. At the next reboot the node's memory ranges can be interleaved and since the call to link_mem_sections() is made in topology_init() while the system is in the SYSTEM_SCHEDULING state, the node's id is not checked, and the sections registered to multiple nodes: $ ls -l /sys/devices/system/memory/memory21/node* total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 In that case, the system is able to boot but if later one of theses memory blocks is hot-unplugged and then hot-plugged, the sysfs inconsistency is detected and this is triggering a BUG_ON(): ------------[ cut here ]------------ kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 NIP: c000000000403f34 LR: c000000000403f2c CTR: 0000000000000000 REGS: c0000004876e3660 TRAP: 0700 Not tainted (5.9.0-rc1+) MSR: 800000000282b033 CR: 24000448 XER: 20040000 CFAR: c000000000846d20 IRQMASK: 0 GPR00: c000000000403f2c c0000004876e38f0 c0000000012f6f00 ffffffffffffffef GPR04: 0000000000000227 c0000004805ae680 0000000000000000 00000004886f0000 GPR08: 0000000000000226 0000000000000003 0000000000000002 fffffffffffffffd GPR12: 0000000088000484 c00000001ec96280 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000004 0000000000000003 GPR20: c00000047814ffe0 c0000007ffff7c08 0000000000000010 c0000000013332c8 GPR24: 0000000000000000 c0000000011f6cc0 0000000000000000 0000000000000000 GPR28: ffffffffffffffef 0000000000000001 0000000150000000 0000000010000000 NIP [c000000000403f34] add_memory_resource+0x244/0x340 LR [c000000000403f2c] add_memory_resource+0x23c/0x340 Call Trace: [c0000004876e38f0] [c000000000403f2c] add_memory_resource+0x23c/0x340 (unreliable) [c0000004876e39c0] [c00000000040408c] __add_memory+0x5c/0xf0 [c0000004876e39f0] [c0000000000e2b94] dlpar_add_lmb+0x1b4/0x500 [c0000004876e3ad0] [c0000000000e3888] dlpar_memory+0x1f8/0xb80 [c0000004876e3b60] [c0000000000dc0d0] handle_dlpar_errorlog+0xc0/0x190 [c0000004876e3bd0] [c0000000000dc398] dlpar_store+0x198/0x4a0 [c0000004876e3c90] [c00000000072e630] kobj_attr_store+0x30/0x50 [c0000004876e3cb0] [c00000000051f954] sysfs_kf_write+0x64/0x90 [c0000004876e3cd0] [c00000000051ee40] kernfs_fop_write+0x1b0/0x290 [c0000004876e3d20] [c000000000438dd8] vfs_write+0xe8/0x290 [c0000004876e3d70] [c0000000004391ac] ksys_write+0xdc/0x130 [c0000004876e3dc0] [c000000000034e40] system_call_exception+0x160/0x270 [c0000004876e3e20] [c00000000000d740] system_call_common+0xf0/0x27c Instruction dump: 48442e35 60000000 0b030000 3cbe0001 7fa3eb78 7bc48402 38a5fffe 7ca5fa14 78a58402 48442db1 60000000 7c7c1b78 <0b030000> 7f23cb78 4bda371d 60000000 ---[ end trace 562fd6c109cd0fb2 ]--- This patch addresses the root cause by not relying on the system_state value to detect whether the call is due to a hot-plug operation. An extra parameter is added to link_mem_sections() detailing whether the operation is due to a hot-plug operation. [1] According to Oscar Salvador, using this qemu command line, ACPI memory hotplug operations are raised at SYSTEM_SCHEDULING state: $QEMU -enable-kvm -machine pc -smp 4,sockets=4,cores=1,threads=1 -cpu host -monitor pty \ -m size=$MEM,slots=255,maxmem=4294967296k \ -numa node,nodeid=0,cpus=0-3,mem=512 -numa node,nodeid=1,mem=512 \ -object memory-backend-ram,id=memdimm0,size=134217728 -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \ -object memory-backend-ram,id=memdimm1,size=134217728 -device pc-dimm,node=0,memdev=memdimm1,id=dimm1,slot=1 \ -object memory-backend-ram,id=memdimm2,size=134217728 -device pc-dimm,node=0,memdev=memdimm2,id=dimm2,slot=2 \ -object memory-backend-ram,id=memdimm3,size=134217728 -device pc-dimm,node=0,memdev=memdimm3,id=dimm3,slot=3 \ -object memory-backend-ram,id=memdimm4,size=134217728 -device pc-dimm,node=1,memdev=memdimm4,id=dimm4,slot=4 \ -object memory-backend-ram,id=memdimm5,size=134217728 -device pc-dimm,node=1,memdev=memdimm5,id=dimm5,slot=5 \ -object memory-backend-ram,id=memdimm6,size=134217728 -device pc-dimm,node=1,memdev=memdimm6,id=dimm6,slot=6 \ Fixes: 4fbce633910e ("mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()") Signed-off-by: Laurent Dufour Reviewed-by: David Hildenbrand Cc: stable@vger.kernel.org Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Andrew Morton Cc: Michal Hocko Cc: Oscar Salvador --- drivers/base/node.c | 85 ++++++++++++++++++++++++++++---------------- include/linux/node.h | 11 +++--- mm/memory_hotplug.c | 3 +- 3 files changed, 64 insertions(+), 35 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index 508b80f6329b..50af16e68d98 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -761,14 +761,36 @@ static int __ref get_nid_for_pfn(unsigned long pfn) return pfn_to_nid(pfn); } +static int do_register_memory_block_under_node(int nid, + struct memory_block *mem_blk) +{ + int ret; + + /* + * If this memory block spans multiple nodes, we only indicate + * the last processed node. + */ + mem_blk->nid = nid; + + ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, + &mem_blk->dev.kobj, + kobject_name(&mem_blk->dev.kobj)); + if (ret) + return ret; + + return sysfs_create_link_nowarn(&mem_blk->dev.kobj, + &node_devices[nid]->dev.kobj, + kobject_name(&node_devices[nid]->dev.kobj)); +} + /* register memory section under specified node if it spans that node */ -static int register_mem_sect_under_node(struct memory_block *mem_blk, - void *arg) +static int register_mem_block_under_node_early(struct memory_block *mem_blk, + void *arg) { unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE; unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); unsigned long end_pfn = start_pfn + memory_block_pfns - 1; - int ret, nid = *(int *)arg; + int nid = *(int *)arg; unsigned long pfn; for (pfn = start_pfn; pfn <= end_pfn; pfn++) { @@ -785,38 +807,33 @@ static int register_mem_sect_under_node(struct memory_block *mem_blk, } /* - * We need to check if page belongs to nid only for the boot - * case, during hotplug we know that all pages in the memory - * block belong to the same node. - */ - if (system_state == SYSTEM_BOOTING) { - page_nid = get_nid_for_pfn(pfn); - if (page_nid < 0) - continue; - if (page_nid != nid) - continue; - } - - /* - * If this memory block spans multiple nodes, we only indicate - * the last processed node. + * We need to check if page belongs to nid only at the boot + * case because node's ranges can be interleaved. */ - mem_blk->nid = nid; - - ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, - &mem_blk->dev.kobj, - kobject_name(&mem_blk->dev.kobj)); - if (ret) - return ret; + page_nid = get_nid_for_pfn(pfn); + if (page_nid < 0) + continue; + if (page_nid != nid) + continue; - return sysfs_create_link_nowarn(&mem_blk->dev.kobj, - &node_devices[nid]->dev.kobj, - kobject_name(&node_devices[nid]->dev.kobj)); + return do_register_memory_block_under_node(nid, mem_blk); } /* mem section does not span the specified node */ return 0; } +/* + * During hotplug we know that all pages in the memory block belong to the same + * node. + */ +static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk, + void *arg) +{ + int nid = *(int *)arg; + + return do_register_memory_block_under_node(nid, mem_blk); +} + /* * Unregister a memory block device under the node it spans. Memory blocks * with multiple nodes cannot be offlined and therefore also never be removed. @@ -832,11 +849,19 @@ void unregister_memory_block_under_nodes(struct memory_block *mem_blk) kobject_name(&node_devices[mem_blk->nid]->dev.kobj)); } -int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn) +int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn, + enum meminit_context context) { + walk_memory_blocks_func_t func; + + if (context == MEMINIT_HOTPLUG) + func = register_mem_block_under_node_hotplug; + else + func = register_mem_block_under_node_early; + return walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn), (void *)&nid, - register_mem_sect_under_node); + func); } #ifdef CONFIG_HUGETLBFS diff --git a/include/linux/node.h b/include/linux/node.h index 4866f32a02d8..014ba3ab2efd 100644 --- a/include/linux/node.h +++ b/include/linux/node.h @@ -99,11 +99,13 @@ extern struct node *node_devices[]; typedef void (*node_registration_func_t)(struct node *); #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_NUMA) -extern int link_mem_sections(int nid, unsigned long start_pfn, - unsigned long end_pfn); +int link_mem_sections(int nid, unsigned long start_pfn, + unsigned long end_pfn, + enum meminit_context context); #else static inline int link_mem_sections(int nid, unsigned long start_pfn, - unsigned long end_pfn) + unsigned long end_pfn, + enum meminit_context context) { return 0; } @@ -128,7 +130,8 @@ static inline int register_one_node(int nid) if (error) return error; /* link memory sections under this node */ - error = link_mem_sections(nid, start_pfn, end_pfn); + error = link_mem_sections(nid, start_pfn, end_pfn, + MEMINIT_EARLY); } return error; diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index fc25886ad719..03df20078827 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1080,7 +1080,8 @@ int __ref add_memory_resource(int nid, struct resource *res) } /* link memory sections under this node.*/ - ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); + ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1), + MEMINIT_HOTPLUG); BUG_ON(ret); /* create new memmap entry */ -- 2.28.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Dufour Date: Tue, 15 Sep 2020 09:41:42 +0000 Subject: [PATCH v3 2/3] mm: don't rely on system state to detect hot-plug operations Message-Id: <20200915094143.79181-3-ldufour@linux.ibm.com> List-Id: References: <20200915094143.79181-1-ldufour@linux.ibm.com> In-Reply-To: <20200915094143.79181-1-ldufour@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable To: akpm@linux-foundation.org, David Hildenbrand , Oscar Salvador , mhocko@suse.com, Greg Kroah-Hartman Cc: linux-mm@kvack.org, "Rafael J . Wysocki" , nathanl@linux.ibm.com, cheloha@linux.ibm.com, Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org In register_mem_sect_under_node() the system_state=E2=80=99s value is check= ed to detect whether the call is made during boot time or during an hot-plug operation. Unfortunately, that check against SYSTEM_BOOTING is wrong because regular memory is registered at SYSTEM_SCHEDULING state. In addition, memory hot-plug operation can be triggered at this system state by the ACPI [1]. So checking against the system state is not enough. The consequence is that on system with interleaved node's ranges like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] This can be seen on PowerPC LPAR after multiple memory hot-plug and hot-unplug operations are done. At the next reboot the node's memory ranges can be interleaved and since the call to link_mem_sections() is made in topology_init() while the system is in the SYSTEM_SCHEDULING state, the node's id is not checked, and the sections registered to multiple nodes: $ ls -l /sys/devices/system/memory/memory21/node* total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 In that case, the system is able to boot but if later one of theses memory blocks is hot-unplugged and then hot-plugged, the sysfs inconsistency is detected and this is triggering a BUG_ON(): ------------[ cut here ]------------ kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZEdK MMU=3DHash SMP NR_CPUS 48 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128= mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 NIP: c000000000403f34 LR: c000000000403f2c CTR: 0000000000000000 REGS: c0000004876e3660 TRAP: 0700 Not tainted (5.9.0-rc1+) MSR: 800000000282b033 CR: 24000448 XER= : 20040000 CFAR: c000000000846d20 IRQMASK: 0 GPR00: c000000000403f2c c0000004876e38f0 c0000000012f6f00 ffffffffffffffef GPR04: 0000000000000227 c0000004805ae680 0000000000000000 00000004886f0000 GPR08: 0000000000000226 0000000000000003 0000000000000002 fffffffffffffffd GPR12: 0000000088000484 c00000001ec96280 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000004 0000000000000003 GPR20: c00000047814ffe0 c0000007ffff7c08 0000000000000010 c0000000013332c8 GPR24: 0000000000000000 c0000000011f6cc0 0000000000000000 0000000000000000 GPR28: ffffffffffffffef 0000000000000001 0000000150000000 0000000010000000 NIP [c000000000403f34] add_memory_resource+0x244/0x340 LR [c000000000403f2c] add_memory_resource+0x23c/0x340 Call Trace: [c0000004876e38f0] [c000000000403f2c] add_memory_resource+0x23c/0x340 (unre= liable) [c0000004876e39c0] [c00000000040408c] __add_memory+0x5c/0xf0 [c0000004876e39f0] [c0000000000e2b94] dlpar_add_lmb+0x1b4/0x500 [c0000004876e3ad0] [c0000000000e3888] dlpar_memory+0x1f8/0xb80 [c0000004876e3b60] [c0000000000dc0d0] handle_dlpar_errorlog+0xc0/0x190 [c0000004876e3bd0] [c0000000000dc398] dlpar_store+0x198/0x4a0 [c0000004876e3c90] [c00000000072e630] kobj_attr_store+0x30/0x50 [c0000004876e3cb0] [c00000000051f954] sysfs_kf_write+0x64/0x90 [c0000004876e3cd0] [c00000000051ee40] kernfs_fop_write+0x1b0/0x290 [c0000004876e3d20] [c000000000438dd8] vfs_write+0xe8/0x290 [c0000004876e3d70] [c0000000004391ac] ksys_write+0xdc/0x130 [c0000004876e3dc0] [c000000000034e40] system_call_exception+0x160/0x270 [c0000004876e3e20] [c00000000000d740] system_call_common+0xf0/0x27c Instruction dump: 48442e35 60000000 0b030000 3cbe0001 7fa3eb78 7bc48402 38a5fffe 7ca5fa14 78a58402 48442db1 60000000 7c7c1b78 <0b030000> 7f23cb78 4bda371d 60000000 ---[ end trace 562fd6c109cd0fb2 ]--- This patch addresses the root cause by not relying on the system_state value to detect whether the call is due to a hot-plug operation. An extra parameter is added to link_mem_sections() detailing whether the operation is due to a hot-plug operation. [1] According to Oscar Salvador, using this qemu command line, ACPI memory hotplug operations are raised at SYSTEM_SCHEDULING state: $QEMU -enable-kvm -machine pc -smp 4,sockets=3D4,cores=3D1,threads=3D1 -cpu= host -monitor pty \ -m size=3D$MEM,slots%5,maxmemB94967296k \ -numa node,nodeid=3D0,cpus=3D0-3,memQ2 -numa node,nodeid=3D1,memQ2 \ -object memory-backend-ram,id=3Dmemdimm0,size=134217728 -device pc-= dimm,node=3D0,memdev=3Dmemdimm0,id=3Ddimm0,slot=3D0 \ -object memory-backend-ram,id=3Dmemdimm1,size=134217728 -device pc-= dimm,node=3D0,memdev=3Dmemdimm1,id=3Ddimm1,slot=3D1 \ -object memory-backend-ram,id=3Dmemdimm2,size=134217728 -device pc-= dimm,node=3D0,memdev=3Dmemdimm2,id=3Ddimm2,slot=3D2 \ -object memory-backend-ram,id=3Dmemdimm3,size=134217728 -device pc-= dimm,node=3D0,memdev=3Dmemdimm3,id=3Ddimm3,slot=3D3 \ -object memory-backend-ram,id=3Dmemdimm4,size=134217728 -device pc-= dimm,node=3D1,memdev=3Dmemdimm4,id=3Ddimm4,slot=3D4 \ -object memory-backend-ram,id=3Dmemdimm5,size=134217728 -device pc-= dimm,node=3D1,memdev=3Dmemdimm5,id=3Ddimm5,slot=3D5 \ -object memory-backend-ram,id=3Dmemdimm6,size=134217728 -device pc-= dimm,node=3D1,memdev=3Dmemdimm6,id=3Ddimm6,slot=3D6 \ Fixes: 4fbce633910e ("mm/memory_hotplug.c: make register_mem_sect_under_nod= e() a callback of walk_memory_range()") Signed-off-by: Laurent Dufour Reviewed-by: David Hildenbrand Cc: stable@vger.kernel.org Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Andrew Morton Cc: Michal Hocko Cc: Oscar Salvador --- drivers/base/node.c | 85 ++++++++++++++++++++++++++++---------------- include/linux/node.h | 11 +++--- mm/memory_hotplug.c | 3 +- 3 files changed, 64 insertions(+), 35 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index 508b80f6329b..50af16e68d98 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -761,14 +761,36 @@ static int __ref get_nid_for_pfn(unsigned long pfn) return pfn_to_nid(pfn); } =20 +static int do_register_memory_block_under_node(int nid, + struct memory_block *mem_blk) +{ + int ret; + + /* + * If this memory block spans multiple nodes, we only indicate + * the last processed node. + */ + mem_blk->nid =3D nid; + + ret =3D sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, + &mem_blk->dev.kobj, + kobject_name(&mem_blk->dev.kobj)); + if (ret) + return ret; + + return sysfs_create_link_nowarn(&mem_blk->dev.kobj, + &node_devices[nid]->dev.kobj, + kobject_name(&node_devices[nid]->dev.kobj)); +} + /* register memory section under specified node if it spans that node */ -static int register_mem_sect_under_node(struct memory_block *mem_blk, - void *arg) +static int register_mem_block_under_node_early(struct memory_block *mem_bl= k, + void *arg) { unsigned long memory_block_pfns =3D memory_block_size_bytes() / PAGE_SIZE; unsigned long start_pfn =3D section_nr_to_pfn(mem_blk->start_section_nr); unsigned long end_pfn =3D start_pfn + memory_block_pfns - 1; - int ret, nid =3D *(int *)arg; + int nid =3D *(int *)arg; unsigned long pfn; =20 for (pfn =3D start_pfn; pfn <=3D end_pfn; pfn++) { @@ -785,38 +807,33 @@ static int register_mem_sect_under_node(struct memory= _block *mem_blk, } =20 /* - * We need to check if page belongs to nid only for the boot - * case, during hotplug we know that all pages in the memory - * block belong to the same node. - */ - if (system_state =3D SYSTEM_BOOTING) { - page_nid =3D get_nid_for_pfn(pfn); - if (page_nid < 0) - continue; - if (page_nid !=3D nid) - continue; - } - - /* - * If this memory block spans multiple nodes, we only indicate - * the last processed node. + * We need to check if page belongs to nid only at the boot + * case because node's ranges can be interleaved. */ - mem_blk->nid =3D nid; - - ret =3D sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, - &mem_blk->dev.kobj, - kobject_name(&mem_blk->dev.kobj)); - if (ret) - return ret; + page_nid =3D get_nid_for_pfn(pfn); + if (page_nid < 0) + continue; + if (page_nid !=3D nid) + continue; =20 - return sysfs_create_link_nowarn(&mem_blk->dev.kobj, - &node_devices[nid]->dev.kobj, - kobject_name(&node_devices[nid]->dev.kobj)); + return do_register_memory_block_under_node(nid, mem_blk); } /* mem section does not span the specified node */ return 0; } =20 +/* + * During hotplug we know that all pages in the memory block belong to the= same + * node. + */ +static int register_mem_block_under_node_hotplug(struct memory_block *mem_= blk, + void *arg) +{ + int nid =3D *(int *)arg; + + return do_register_memory_block_under_node(nid, mem_blk); +} + /* * Unregister a memory block device under the node it spans. Memory blocks * with multiple nodes cannot be offlined and therefore also never be remo= ved. @@ -832,11 +849,19 @@ void unregister_memory_block_under_nodes(struct memor= y_block *mem_blk) kobject_name(&node_devices[mem_blk->nid]->dev.kobj)); } =20 -int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_= pfn) +int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_= pfn, + enum meminit_context context) { + walk_memory_blocks_func_t func; + + if (context =3D MEMINIT_HOTPLUG) + func =3D register_mem_block_under_node_hotplug; + else + func =3D register_mem_block_under_node_early; + return walk_memory_blocks(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn - start_pfn), (void *)&nid, - register_mem_sect_under_node); + func); } =20 #ifdef CONFIG_HUGETLBFS diff --git a/include/linux/node.h b/include/linux/node.h index 4866f32a02d8..014ba3ab2efd 100644 --- a/include/linux/node.h +++ b/include/linux/node.h @@ -99,11 +99,13 @@ extern struct node *node_devices[]; typedef void (*node_registration_func_t)(struct node *); =20 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_NUMA) -extern int link_mem_sections(int nid, unsigned long start_pfn, - unsigned long end_pfn); +int link_mem_sections(int nid, unsigned long start_pfn, + unsigned long end_pfn, + enum meminit_context context); #else static inline int link_mem_sections(int nid, unsigned long start_pfn, - unsigned long end_pfn) + unsigned long end_pfn, + enum meminit_context context) { return 0; } @@ -128,7 +130,8 @@ static inline int register_one_node(int nid) if (error) return error; /* link memory sections under this node */ - error =3D link_mem_sections(nid, start_pfn, end_pfn); + error =3D link_mem_sections(nid, start_pfn, end_pfn, + MEMINIT_EARLY); } =20 return error; diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index fc25886ad719..03df20078827 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1080,7 +1080,8 @@ int __ref add_memory_resource(int nid, struct resourc= e *res) } =20 /* link memory sections under this node.*/ - ret =3D link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); + ret =3D link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1), + MEMINIT_HOTPLUG); BUG_ON(ret); =20 /* create new memmap entry */ --=20 2.28.0