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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 BD644C433E0 for ; Thu, 21 May 2020 01:44:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 47D3D206D4 for ; Thu, 21 May 2020 01:44:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="e4sfz7hF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47D3D206D4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BE43680008; Wed, 20 May 2020 21:44:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B6EC680007; Wed, 20 May 2020 21:44:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A5E9E80008; Wed, 20 May 2020 21:44:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0210.hostedemail.com [216.40.44.210]) by kanga.kvack.org (Postfix) with ESMTP id 89F8480007 for ; Wed, 20 May 2020 21:44:17 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 4C7178248076 for ; Thu, 21 May 2020 01:44:17 +0000 (UTC) X-FDA: 76839030954.01.night52_4270cbb5aa340 X-HE-Tag: night52_4270cbb5aa340 X-Filterd-Recvd-Size: 9112 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Thu, 21 May 2020 01:44:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590025455; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=CCEasa2J5evFTeUb/BLxZS5fCWTF6bLrwK37bZkjLbI=; b=e4sfz7hFvszewDYZAtBBPdSlyz2Sxo46mvZR7yrMw3S7yD576RKODWzPQ6E0oXhSpileTT vSsHQv51waw8VgwLXr27yhjDP1tlQwCe+UzUuHHVAdZlP6/VnHuSSSFnJ/hh++geSfrnKQ pWpSmhWLHMIQoJsQZFhWR/WOLrr9A+0= 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-202-EPUs-rCnNV-k72o9zYjVGg-1; Wed, 20 May 2020 21:44:13 -0400 X-MC-Unique: EPUs-rCnNV-k72o9zYjVGg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5904C1005510; Thu, 21 May 2020 01:44:12 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-86.pek2.redhat.com [10.72.12.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4B7535C1D0; Thu, 21 May 2020 01:44:08 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, cai@lca.pw, mgorman@suse.de, mhocko@kernel.org, rppt@linux.ibm.com, bhe@redhat.com Subject: [PATCH] mm/compaction: Fix the incorrect hole in fast_isolate_freepages() Date: Thu, 21 May 2020 09:44:07 +0800 Message-Id: <20200521014407.29690-1-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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: Qian reported that a crash happened in compaction. http://lkml.kernel.org/r/8C537EB7-85EE-4DCF-943E-3CC0ED0DF56D@lca.pw LTP: starting swapping01 (swapping01 -i 5) page:ffffea0000aa0000 refcount:1 mapcount:0 mapping:000000002243743b index:0x0 flags: 0x1fffe000001000(reserved) raw: 001fffe000001000 ffffea0000aa0008 ffffea0000aa0008 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn)) page_owner info is not present (never set?) ------------[ cut here ]------------ kernel BUG at mm/page_alloc.c:533! ... CPU: 17 PID: 218 Comm: kcompactd0 Not tainted 5.7.0-rc2-next-20200423+ #7 ... RIP: 0010:set_pfnblock_flags_mask+0x150/0x210 ... RSP: 0018:ffffc900042ff858 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff9a002382 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8884535b8e6c RBP: ffffc900042ff8b8 R08: ffffed108a6b8459 R09: ffffed108a6b8459 R10: ffff8884535c22c7 R11: ffffed108a6b8458 R12: 000000000002a800 R13: ffffea0000aa0000 R14: ffff88847fff3000 R15: ffff88847fff3040 FS: 0000000000000000(0000) GS:ffff888453580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd1eb4a1000 CR3: 000000083154c000 CR4: 00000000003406e0 Call Trace: isolate_freepages+0xb20/0x1140 ? isolate_freepages_block+0x730/0x730 ? mark_held_locks+0x34/0xb0 ? free_unref_page+0x7d/0x90 ? free_unref_page+0x7d/0x90 ? check_flags.part.28+0x86/0x220 compaction_alloc+0xdd/0x100 migrate_pages+0x304/0x17e0 ? __ClearPageMovable+0x100/0x100 ? isolate_freepages+0x1140/0x1140 compact_zone+0x1249/0x1e90 ? compaction_suitable+0x260/0x260 kcompactd_do_work+0x231/0x650 ? sysfs_compact_node+0x80/0x80 ? finish_wait+0xe6/0x110 kcompactd+0x162/0x490 ? kcompactd_do_work+0x650/0x650 ? finish_wait+0x110/0x110 ? __kasan_check_read+0x11/0x20 ? __kthread_parkme+0xd4/0xf0 ? kcompactd_do_work+0x650/0x650 kthread+0x1f7/0x220 ? kthread_create_worker_on_cpu+0xc0/0xc0 ret_from_fork+0x27/0x50 After investigation, it turns out that this is introduced by commit of linux-next: commit f6edbdb71877 ("mm: memmap_init: iterate over memblock regions rather that check each PFN"). After investigation, it turns out that this is introduced by commit of linux-next, the patch subject is: "mm: memmap_init: iterate over memblock regions rather that check each PFN". Qian added debugging code. The debugging log shows that the fault page is 0x2a800000. From the system e820 map which is pasted at bottom, the page is in e820 reserved range: BIOS-e820: [mem 0x0000000029ffe000-0x000000002a80afff] reserved And it's in section [0x28000000, 0x2fffffff]. In that secion, there are several usable ranges and some e820 reserved ranges. For this kind of e820 reserved range, it won't be added to memblock allocator. However, init_unavailable_mem() will initialize to add them into node 0, zone 0. Before that commit, later, memmap_init() will add e820 reserved ranges into the zone where they are contained, because it can pass the checking of early_pfn_valid() and early_pfn_in_nid(). In this case, the e820 reserved range where fault page 0x2a800000 is located is added into DMA32 zone. After that commit, the e820 reserved rgions are kept in node 0, zone 0, since we iterate over memblock regions to iniatialize in memmap_init() instead, their node and zone won't be changed. Now, fast_isolate_freepages() will use min mark directly as the migration target if no page is found from buddy. However, the min mark is not checked carefully, it could be in e820 reserved range, and trigger the VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn)) when try to mark it as skip. Here, let's call pageblock_pfn_to_page() to get page of min_pfn, since it will do careful checks and return NULL if the pfn is not qualified. [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000008bfff] usable [ 0.000000] BIOS-e820: [mem 0x000000000008c000-0x000000000009ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x0000000028328fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000028329000-0x0000000028568fff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000028569000-0x0000000028d85fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000028d86000-0x0000000028ee5fff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000028ee6000-0x0000000029a04fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000029a05000-0x0000000029a08fff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000029a09000-0x0000000029ee4fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000029ee5000-0x0000000029ef2fff] ACPI data [ 0.000000] BIOS-e820: [mem 0x0000000029ef3000-0x0000000029f22fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000029f23000-0x0000000029f23fff] ACPI data [ 0.000000] BIOS-e820: [mem 0x0000000029f24000-0x0000000029f24fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000029f25000-0x0000000029f28fff] ACPI data [ 0.000000] BIOS-e820: [mem 0x0000000029f29000-0x0000000029f29fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x0000000029f2a000-0x0000000029f2bfff] ACPI data [ 0.000000] BIOS-e820: [mem 0x0000000029f2c000-0x0000000029f2cfff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000029f2d000-0x0000000029f2ffff] ACPI data [ 0.000000] BIOS-e820: [mem 0x0000000029f30000-0x0000000029ffdfff] usable [ 0.000000] BIOS-e820: [mem 0x0000000029ffe000-0x000000002a80afff] reserved [ 0.000000] BIOS-e820: [mem 0x000000002a80b000-0x000000002a80efff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x000000002a80f000-0x000000002a81ffff] reserved [ 0.000000] BIOS-e820: [mem 0x000000002a820000-0x000000002a822fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x000000002a823000-0x0000000033a22fff] usable [ 0.000000] BIOS-e820: [mem 0x0000000033a23000-0x0000000033a32fff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000033a33000-0x0000000033a42fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x0000000033a43000-0x0000000033a52fff] ACPI data [ 0.000000] BIOS-e820: [mem 0x0000000033a53000-0x0000000077ffffff] usable [ 0.000000] BIOS-e820: [mem 0x0000000078000000-0x000000008fffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed80000-0x00000000fed80fff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000087effffff] usable [ 0.000000] BIOS-e820: [mem 0x000000087f000000-0x000000087fffffff] reserved Reported-by: Qian Cai Signed-off-by: Baoquan He --- mm/compaction.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index 67fd317f78db..9ce4cff4d407 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1418,7 +1418,9 @@ fast_isolate_freepages(struct compact_control *cc) cc->free_pfn = highest; } else { if (cc->direct_compaction && pfn_valid(min_pfn)) { - page = pfn_to_page(min_pfn); + page = pageblock_pfn_to_page(min_pfn, + pageblock_end_pfn(min_pfn), + cc->zone); cc->free_pfn = min_pfn; } } -- 2.17.2