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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BAB7C433F5 for ; Sat, 23 Apr 2022 03:16:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 925A86B0073; Fri, 22 Apr 2022 23:16:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8D4B86B0074; Fri, 22 Apr 2022 23:16:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7C5BE6B0075; Fri, 22 Apr 2022 23:16:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 6EB636B0073 for ; Fri, 22 Apr 2022 23:16:27 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 497C425900 for ; Sat, 23 Apr 2022 03:16:27 +0000 (UTC) X-FDA: 79386680814.27.B0B7506 Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) by imf14.hostedemail.com (Postfix) with ESMTP id 3443010002A for ; Sat, 23 Apr 2022 03:16:24 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=xuyu@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VArfqeo_1650683781; Received: from 30.236.51.165(mailfrom:xuyu@linux.alibaba.com fp:SMTPD_---0VArfqeo_1650683781) by smtp.aliyun-inc.com(127.0.0.1); Sat, 23 Apr 2022 11:16:21 +0800 Message-ID: <8e1a882c-8568-57f2-216a-703f220e0e3f@linux.alibaba.com> Date: Sat, 23 Apr 2022 11:16:20 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v2] mm/memory-failure.c: skip huge_zero_page in memory_failure() Content-Language: en-US From: Yu Xu To: linux-mm@kvack.org, Yang Shi , David Hildenbrand , anshuman.khandual@arm.com, Naoya Horiguchi Cc: akpm@linux-foundation.org, linmiaohe@huawei.com, osalvador@suse.de References: <497d3835612610e370c74e697ea3c721d1d55b9c.1649775850.git.xuyu@linux.alibaba.com> In-Reply-To: <497d3835612610e370c74e697ea3c721d1d55b9c.1649775850.git.xuyu@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 3443010002A X-Stat-Signature: 5o7qy7xjsnrp75hcruccj3ekwsxqr86n Authentication-Results: imf14.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf14.hostedemail.com: domain of xuyu@linux.alibaba.com designates 115.124.30.57 as permitted sender) smtp.mailfrom=xuyu@linux.alibaba.com X-Rspam-User: X-HE-Tag: 1650683784-216391 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: For this patch v2, Yang, David, Anshuman and Naoya all agree to fix the bug in split_huge_page_to_list(), i.e., to replace the BUG to WARN + returning -EBUSY for huge_zero_page. However, this patch v2 has just been merged into linux mainline. Sorry for that I didn't hurry up. So now, should we continue sending v3, or should we end this thread, and start a successive patch for optimization? On 4/12/22 11:11 PM, Xu Yu wrote: > Kernel panic when injecting memory_failure for the global huge_zero_page, > when CONFIG_DEBUG_VM is enabled, as follows. > > [ 5.582720] Injecting memory failure for pfn 0x109ff9 at process virtual address 0x20ff9000 > [ 5.583786] page:00000000fb053fc3 refcount:2 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109e00 > [ 5.584900] head:00000000fb053fc3 order:9 compound_mapcount:0 compound_pincount:0 > [ 5.585796] flags: 0x17fffc000010001(locked|head|node=0|zone=2|lastcpupid=0x1ffff) > [ 5.586712] raw: 017fffc000010001 0000000000000000 dead000000000122 0000000000000000 > [ 5.587640] raw: 0000000000000000 0000000000000000 00000002ffffffff 0000000000000000 > [ 5.588565] page dumped because: VM_BUG_ON_PAGE(is_huge_zero_page(head)) > [ 5.589398] ------------[ cut here ]------------ > [ 5.589952] kernel BUG at mm/huge_memory.c:2499! > [ 5.590516] invalid opcode: 0000 [#1] PREEMPT SMP PTI > [ 5.591120] CPU: 6 PID: 553 Comm: split_bug Not tainted 5.18.0-rc1+ #11 > [ 5.591904] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 3288b3c 04/01/2014 > [ 5.592817] RIP: 0010:split_huge_page_to_list+0x66a/0x880 > [ 5.593469] Code: 84 9b fb ff ff 48 8b 7c 24 08 31 f6 e8 9f 5d 2a 00 b8 b8 02 00 00 e9 e8 fb ff ff 48 c7 c6 e8 47 3c 82 4c b > [ 5.595806] RSP: 0018:ffffc90000dcbdf8 EFLAGS: 00010246 > [ 5.596434] RAX: 000000000000003c RBX: 0000000000000001 RCX: 0000000000000000 > [ 5.597322] RDX: 0000000000000000 RSI: ffffffff823e4c4f RDI: 00000000ffffffff > [ 5.598162] RBP: ffff88843fffdb40 R08: 0000000000000000 R09: 00000000fffeffff > [ 5.598999] R10: ffffc90000dcbc48 R11: ffffffff82d68448 R12: ffffea0004278000 > [ 5.599849] R13: ffffffff823c6203 R14: 0000000000109ff9 R15: ffffea000427fe40 > [ 5.600693] FS: 00007fc375a26740(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000 > [ 5.601640] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 5.602304] CR2: 00007fc3757c9290 CR3: 0000000102174006 CR4: 00000000003706e0 > [ 5.603139] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 5.603977] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 5.604806] Call Trace: > [ 5.605101] > [ 5.605357] ? __irq_work_queue_local+0x39/0x70 > [ 5.605904] try_to_split_thp_page+0x3a/0x130 > [ 5.606430] memory_failure+0x128/0x800 > [ 5.606888] madvise_inject_error.cold+0x8b/0xa1 > [ 5.607444] __x64_sys_madvise+0x54/0x60 > [ 5.607915] do_syscall_64+0x35/0x80 > [ 5.608347] entry_SYSCALL_64_after_hwframe+0x44/0xae > [ 5.608949] RIP: 0033:0x7fc3754f8bf9 > [ 5.609374] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8 > [ 5.611554] RSP: 002b:00007ffeda93a1d8 EFLAGS: 00000217 ORIG_RAX: 000000000000001c > [ 5.612441] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc3754f8bf9 > [ 5.613269] RDX: 0000000000000064 RSI: 0000000000003000 RDI: 0000000020ff9000 > [ 5.614108] RBP: 00007ffeda93a200 R08: 0000000000000000 R09: 0000000000000000 > [ 5.614946] R10: 00000000ffffffff R11: 0000000000000217 R12: 0000000000400490 > [ 5.615787] R13: 00007ffeda93a2e0 R14: 0000000000000000 R15: 0000000000000000 > [ 5.616626] > > This makes huge_zero_page bail out explicitly before split in > memory_failure(), thus the panic above won't happen again. > > Reported-by: Abaci > Suggested-by: Naoya Horiguchi > Cc: Miaohe Lin > Cc: Oscar Salvador > Signed-off-by: Xu Yu > --- > mm/memory-failure.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index dcb6bb9cf731..8788ea49bd28 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1799,6 +1799,19 @@ int memory_failure(unsigned long pfn, int flags) > } > > if (PageTransHuge(hpage)) { > + /* > + * Bail out before SetPageHasHWPoisoned() if hpage is > + * huge_zero_page, although PG_has_hwpoisoned is not > + * checked in set_huge_zero_page(). > + * > + * TODO: Handle memory failure of huge_zero_page thoroughly. > + */ > + if (is_huge_zero_page(hpage)) { > + action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED); > + res = -EBUSY; > + goto unlock_mutex; > + } > + > /* > * The flag must be set after the refcount is bumped > * otherwise it may race with THP split. -- Thanks, Yu