From patchwork Thu Nov 3 21:36:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Shi X-Patchwork-Id: 13031042 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 35E70C433FE for ; Thu, 3 Nov 2022 21:36:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 854716B0073; Thu, 3 Nov 2022 17:36:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8046F6B0074; Thu, 3 Nov 2022 17:36:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 656206B0075; Thu, 3 Nov 2022 17:36:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 50E356B0073 for ; Thu, 3 Nov 2022 17:36:48 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 1A50A1414B7 for ; Thu, 3 Nov 2022 21:36:48 +0000 (UTC) X-FDA: 80093440896.15.968D96C Received: from mail-pj1-f43.google.com (mail-pj1-f43.google.com [209.85.216.43]) by imf07.hostedemail.com (Postfix) with ESMTP id B9A0640002 for ; Thu, 3 Nov 2022 21:36:47 +0000 (UTC) Received: by mail-pj1-f43.google.com with SMTP id gw22so2886212pjb.3 for ; Thu, 03 Nov 2022 14:36:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=6zbt6qB/1c/+1gLU+/4sNCX68bCG+yMYvDrFsBMAeuQ=; b=VKk+6TpjGdp93LuLE9ePqP553eYxDkMkD6mL4qi4cgGqPnoDWlWLHQKgdmvQUZFlWk K8w76FC/2Pkgd1TEAnIynxANEvR9oAn4/ovdI4PoNqALUtUiBJKAeahV6658YhiGyotB a1ubPt1i52WQeB/MHa3jH3xgvBCbEmjWDTOSy2kAcmmT3LztfJK+82elHSj20QaS1Tr+ U4w5chhei1gsNQpH0IMNXUkhu3HAsxi7CAPa1tBsyk9rSseSpqrjD8ZzmIzaSIDu24Dn bp8SLKgOfC0N2ISE5Pzwxa1Cc3o68Vc5zJ5XUywENHsL6TtB2/0bVZHeZ3Lluisa5MKQ Wgfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6zbt6qB/1c/+1gLU+/4sNCX68bCG+yMYvDrFsBMAeuQ=; b=MVHvjcjP7WSIzvWEq/1jD9DzgsJS/3fSqkc39/5htgP7lBQRWDYK/jdC7jEdk28kL4 3LxaPSBe0372ew13lXcv5jeEj5hnX9KkUkKG35lI9duqfL8IDkTK1yl7iGrLnPAbifKl jdPG5iINyQ01ad9fZ27PgraC9ch3tFhGQfKav0HTOOzPtSTkWKYFZ38hg2jcPwv2Kx6e fbwBr5CQBve75RinOeiHpzf2xQlqSirl7aztEraWpqeI1UgGZDm1RhvcOrxKsGLtFH+q MHR7G3IafA4Q7U/baJ6DCRqrs4mLCQLyQszF4Mwr4gAPm4U25o+L8CbmjolfZLhv5+et 0QAw== X-Gm-Message-State: ACrzQf0z/p/Pc+iAWdrV4SAxloabl5B7EdWv82zE0xZRrpqzMdvXQuHq 2jh/aDa4vsPcbh4SAaGj0s0= X-Google-Smtp-Source: AMsMyM6obNd7XwlBaMgkd7D5GeCTeE9NuIwQ9tms0i0f1S3WmYpmSZVpypgi51Bh1rFN5jWR+n5Kug== X-Received: by 2002:a17:90a:f0d1:b0:213:473e:6ff0 with SMTP id fa17-20020a17090af0d100b00213473e6ff0mr32774003pjb.87.1667511406761; Thu, 03 Nov 2022 14:36:46 -0700 (PDT) Received: from localhost.localdomain (c-67-174-241-145.hsd1.ca.comcast.net. [67.174.241.145]) by smtp.gmail.com with ESMTPSA id f132-20020a62388a000000b0056da8c41bbasm1195438pfa.161.2022.11.03.14.36.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Nov 2022 14:36:46 -0700 (PDT) From: Yang Shi To: zokeefe@google.com, mhocko@suse.com, akpm@linux-foundation.org Cc: shy828301@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [v2 PATCH 2/2] mm: don't warn if the node is offlined Date: Thu, 3 Nov 2022 14:36:41 -0700 Message-Id: <20221103213641.7296-2-shy828301@gmail.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20221103213641.7296-1-shy828301@gmail.com> References: <20221103213641.7296-1-shy828301@gmail.com> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667511407; a=rsa-sha256; cv=none; b=Lk3Ndr2sv7whcgSw4G7dwS8rEyOWEptap989atM9656eM8/U5Xpft6/u0px6+hXrRMDW6T qyQhKfT8kEAZQM3aGvEniV8wyRty4CpxnKDcUHh8fUzxAmRBl5ax7fp+BqgbXB+7lu5Rna g6gFgibbl5TpbzG2WaCzWvxINsLU8/k= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=VKk+6Tpj; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf07.hostedemail.com: domain of shy828301@gmail.com designates 209.85.216.43 as permitted sender) smtp.mailfrom=shy828301@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667511407; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=6zbt6qB/1c/+1gLU+/4sNCX68bCG+yMYvDrFsBMAeuQ=; b=JMVpoF6zuIESQNAFjbM03JsDAJwvm4dM8JjzH9XjuR8aadfSBX1BwBODCcY0BrMxZWFUke ILG8VmFkjpdhwoysIwF7PbAoygKrE9ekH4gR1Y6iuOlJjdiU4gPf2x4nHhOKs4rDHiksf5 viiIeLKCA6EDmQnlbIVUyDIqx9XrMRY= X-Stat-Signature: uhhy1r1efhc9eeezj9tyotds57y6qcfd X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: B9A0640002 X-Rspam-User: Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=VKk+6Tpj; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf07.hostedemail.com: domain of shy828301@gmail.com designates 209.85.216.43 as permitted sender) smtp.mailfrom=shy828301@gmail.com X-HE-Tag: 1667511407-536609 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: Syzbot reported the below splat: WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 __alloc_pages_node include/linux/gfp.h:221 [inline] WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 hpage_collapse_alloc_page mm/khugepaged.c:807 [inline] WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963 Modules linked in: CPU: 1 PID: 3646 Comm: syz-executor210 Not tainted 6.1.0-rc1-syzkaller-00454-ga70385240892 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:__alloc_pages_node include/linux/gfp.h:221 [inline] RIP: 0010:hpage_collapse_alloc_page mm/khugepaged.c:807 [inline] RIP: 0010:alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963 Code: e5 01 4c 89 ee e8 6e f9 ae ff 4d 85 ed 0f 84 28 fc ff ff e8 70 fc ae ff 48 8d 6b ff 4c 8d 63 07 e9 16 fc ff ff e8 5e fc ae ff <0f> 0b e9 96 fa ff ff 41 bc 1a 00 00 00 e9 86 fd ff ff e8 47 fc ae RSP: 0018:ffffc90003fdf7d8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888077f457c0 RSI: ffffffff81cd8f42 RDI: 0000000000000001 RBP: ffff888079388c0c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6b48ccf700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b48a819f0 CR3: 00000000171e7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: collapse_file+0x1ca/0x5780 mm/khugepaged.c:1715 hpage_collapse_scan_file+0xd6c/0x17a0 mm/khugepaged.c:2156 madvise_collapse+0x53a/0xb40 mm/khugepaged.c:2611 madvise_vma_behavior+0xd0a/0x1cc0 mm/madvise.c:1066 madvise_walk_vmas+0x1c7/0x2b0 mm/madvise.c:1240 do_madvise.part.0+0x24a/0x340 mm/madvise.c:1419 do_madvise mm/madvise.c:1432 [inline] __do_sys_madvise mm/madvise.c:1432 [inline] __se_sys_madvise mm/madvise.c:1430 [inline] __x64_sys_madvise+0x113/0x150 mm/madvise.c:1430 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6b48a4eef9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6b48ccf318 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f6b48af0048 RCX: 00007f6b48a4eef9 RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000000020000000 RBP: 00007f6b48af0040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6b48aa53a4 R13: 00007f6b48bffcbf R14: 00007f6b48ccf400 R15: 0000000000022000 It is because khugepaged allocates pages with __GFP_THISNODE, but the preferred node is offlined. The previous patch fixed the khugepaged code to avoid allocating page from non-existing node. But it is still racy against memory hotremove. There is no synchronization with the memory hotplug so it is possible that memory gets offline during a longer taking scanning. So this warning still seems not quite helpful because: * There is no guarantee the node is online for __GFP_THISNODE context for all the callsites. * Kernel just fails the allocation regardless the warning, and it looks all callsites handle the allocation failure gracefully. It is actually even harmful for those running in panic-on-warn mode. So removing the warning seems like a good move. Reported-by: syzbot+0044b22d177870ee974f@syzkaller.appspotmail.com Signed-off-by: Yang Shi Reviewed-by: Zach O'Keefe Acked-by: Michal Hocko --- v2: * Added patch 1/2. * Reworded the commit log per Michal. include/linux/gfp.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index ef4aea3b356e..594d6dee5646 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -218,7 +218,6 @@ static inline struct page * __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order) { VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES); - VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid)); return __alloc_pages(gfp_mask, order, nid, NULL); } @@ -227,7 +226,6 @@ static inline struct folio *__folio_alloc_node(gfp_t gfp, unsigned int order, int nid) { VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES); - VM_WARN_ON((gfp & __GFP_THISNODE) && !node_online(nid)); return __folio_alloc(gfp, order, nid, NULL); }