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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,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 5D2B7C43461 for ; Tue, 8 Sep 2020 17:40:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D1972087D for ; Tue, 8 Sep 2020 17:40:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JjM76+sC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727940AbgIHRkj (ORCPT ); Tue, 8 Sep 2020 13:40:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:51234 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732039AbgIHRk1 (ORCPT ); Tue, 8 Sep 2020 13:40:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599586824; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=7vNhc54hxlUIUhTC2VasBxK/L1FhxfTYvYlcm/PwRr0=; b=JjM76+sCfqHa+RmbiB9udr5lQPNlQ/NcNQARuU+mkN7HQWAGKqZHjD7mI9cLMAfEOJg84I UNSp2aBuYOxxbl3mYGXEGpQto63GVvgUHPLYMZxpOSAEq+qpLapzmeZuMXl7EB7cutstNv ncC1AonNV1lzrYZidt0JiMxnRX+ahGU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-393-5Oo7cVj0MvOL9-kwkx_xWQ-1; Tue, 08 Sep 2020 13:40:22 -0400 X-MC-Unique: 5Oo7cVj0MvOL9-kwkx_xWQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CE7BA1084D89; Tue, 8 Sep 2020 17:40:20 +0000 (UTC) Received: from [10.36.115.46] (ovpn-115-46.ams2.redhat.com [10.36.115.46]) by smtp.corp.redhat.com (Postfix) with ESMTP id E49E4838A6; Tue, 8 Sep 2020 17:40:18 +0000 (UTC) Subject: Re: [PATCH] mm: don't rely on system state to detect hot-plug operations To: Greg Kroah-Hartman , Laurent Dufour Cc: akpm@linux-foundation.org, salvador@suse.de, rafael@kernel.org, nathanl@linux.ibm.com, mhocko@kernel.org, cheloha@linux.ibm.com, stable@vger.kernel.org References: <5cbd92e1-c00a-4253-0119-c872bfa0f2bc@redhat.com> <20200908170835.85440-1-ldufour@linux.ibm.com> <20200908173113.GB218801@kroah.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63W5Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAjwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat GmbH Message-ID: Date: Tue, 8 Sep 2020 19:40:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200908173113.GB218801@kroah.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 08.09.20 19:31, Greg Kroah-Hartman wrote: > On Tue, Sep 08, 2020 at 07:08:35PM +0200, Laurent Dufour wrote: >> In register_mem_sect_under_node() the system_state’s value is checked to >> detect whether the operation the call is made during boot time or during an >> hot-plug operation. Unfortunately, that check is wrong on some >> architecture, and may lead to sections being registered under multiple >> nodes if node's memory ranges are interleaved. >> >> 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 multiple times. In >> that case, the system is able to boot but later hot-plug operation may lead >> to this panic because the node's links are correctly broken: >> >> ------------[ 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 or not. An >> additional parameter is added to link_mem_sections() to tell the context of >> the call and this parameter is propagated to register_mem_sect_under_node() >> throuugh the walk_memory_blocks()'s call. >> >> Fixes: 4fbce633910e ("mm/memory_hotplug.c: make register_mem_sect_under_node() a callback of walk_memory_range()") >> Signed-off-by: Laurent Dufour >> Cc: stable@vger.kernel.org >> Cc: Greg Kroah-Hartman >> Cc: "Rafael J. Wysocki" >> Cc: Andrew Morton >> --- >> drivers/base/node.c | 20 +++++++++++++++----- >> include/linux/node.h | 6 +++--- >> mm/memory_hotplug.c | 3 ++- >> 3 files changed, 20 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/base/node.c b/drivers/base/node.c >> index 508b80f6329b..27f828eeb531 100644 >> --- a/drivers/base/node.c >> +++ b/drivers/base/node.c >> @@ -762,14 +762,19 @@ static int __ref get_nid_for_pfn(unsigned long pfn) >> } >> >> /* register memory section under specified node if it spans that node */ >> +struct rmsun_args { >> + int nid; >> + bool hotadd; >> +}; >> static int register_mem_sect_under_node(struct memory_block *mem_blk, >> - void *arg) >> + void *args) >> { >> 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 ret, nid = ((struct rmsun_args *)args)->nid; >> unsigned long pfn; >> + bool hotadd = ((struct rmsun_args *)args)->hotadd; >> >> for (pfn = start_pfn; pfn <= end_pfn; pfn++) { >> int page_nid; >> @@ -789,7 +794,7 @@ static int register_mem_sect_under_node(struct memory_block *mem_blk, >> * case, during hotplug we know that all pages in the memory >> * block belong to the same node. >> */ >> - if (system_state == SYSTEM_BOOTING) { >> + if (!hotadd) { >> page_nid = get_nid_for_pfn(pfn); >> if (page_nid < 0) >> continue; >> @@ -832,10 +837,15 @@ 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, >> + bool hotadd) >> { >> + struct rmsun_args args; >> + >> + args.nid = nid; >> + args.hotadd = hotadd; >> return walk_memory_blocks(PFN_PHYS(start_pfn), >> - PFN_PHYS(end_pfn - start_pfn), (void *)&nid, >> + PFN_PHYS(end_pfn - start_pfn), (void *)&args, >> register_mem_sect_under_node); >> } >> >> diff --git a/include/linux/node.h b/include/linux/node.h >> index 4866f32a02d8..6df9a4548650 100644 >> --- a/include/linux/node.h >> +++ b/include/linux/node.h >> @@ -100,10 +100,10 @@ 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); >> + unsigned long end_pfn, bool hotadd); >> #else >> static inline int link_mem_sections(int nid, unsigned long start_pfn, >> - unsigned long end_pfn) >> + unsigned long end_pfn, bool hotadd) > > Adding a random boolean flag to a function is a horrible way to do > anything. > > Now you need to look up what that flag means every time you run across a > caller, breaking your reading of what is happening. > > Make this two different functions please, that describe what they do, > and have them call a common "helper function" that does the work with > the flag if you really want to do this type of thing. > > link_mem_sections() and link_mem_sections_hotadd()? > > But not this way, please no. For memmap_init_zone() we solved it via an enum with MEMMAP_HOTPLUG vs MEMMAP_EARLY. Maybe we can generalize, because it tries to tackle roughly the same thing. > > thanks, > > greg k-h > -- Thanks, David / dhildenb