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=-8.4 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,USER_AGENT_SANE_1 autolearn=unavailable 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 3CC21C2D0BF for ; Tue, 10 Dec 2019 13:44:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DAF87208C3 for ; Tue, 10 Dec 2019 13:44:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KF16Cv/w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DAF87208C3 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 6F5A66B2C9B; Tue, 10 Dec 2019 08:44:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6A5C66B2C9C; Tue, 10 Dec 2019 08:44:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 595886B2C9D; Tue, 10 Dec 2019 08:44:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 43B746B2C9B for ; Tue, 10 Dec 2019 08:44:54 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id F0AD7583C for ; Tue, 10 Dec 2019 13:44:53 +0000 (UTC) X-FDA: 76249352466.03.wood82_47b91789af11e X-HE-Tag: wood82_47b91789af11e X-Filterd-Recvd-Size: 13309 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Dec 2019 13:44:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575985492; 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=qZRftvwkHIToEw0UmAjHzdaxfkbvBsE3MuY4WTmXwwk=; b=KF16Cv/wa5tSQQBIzWZeDLks2OiVgKtjy/CwkXq2S14s8Qeu1X0whEVdhtBWoBlnl5K2/7 6iz1Wrdzfcs8mGjJ0cJ09npei1vzYb/WUvyyuurxyonTPEqfpdaz2ceaFNz8bBNbudOCDi b8hyfxXeau1GevaUhEvf8PxjJFsNVBc= 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-422-ylpqTWCfO-KcAPTKJJFxag-1; Tue, 10 Dec 2019 08:44:49 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B9E34802B60; Tue, 10 Dec 2019 13:44:47 +0000 (UTC) Received: from [10.36.117.222] (ovpn-117-222.ams2.redhat.com [10.36.117.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5E80A261A7; Tue, 10 Dec 2019 13:44:39 +0000 (UTC) Subject: Re: [PATCH v2] virtio-balloon: fix managed page counts when migrating pages between zones To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Yumei Huang , stable@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , Jiang Liu , Andrew Morton , virtualization@lists.linux-foundation.org, Igor Mammedov References: <20191205092420.6934-1-david@redhat.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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz 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+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: <13e33ff9-22f2-c02a-811e-2d087e42e1ce@redhat.com> Date: Tue, 10 Dec 2019 14:44:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191205092420.6934-1-david@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: ylpqTWCfO-KcAPTKJJFxag-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit 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: On 05.12.19 10:24, David Hildenbrand wrote: > In case we have to migrate a ballon page to a newpage of another zone, the > managed page count of both zones is wrong. Paired with memory offlining > (which will adjust the managed page count), we can trigger kernel crashes > and all kinds of different symptoms. > > One way to reproduce: > 1. Start a QEMU guest with 4GB, no NUMA > 2. Hotplug a 1GB DIMM and only the memory to ZONE_NORMAL s/only/online/ as requested by Igor. > 3. Inflate the balloon to 1GB > 4. Unplug the DIMM (be quick, otherwise unmovable data ends up on it) > 5. Observe /proc/zoneinfo > Node 0, zone Normal > pages free 16810 > min 24848885473806 > low 18471592959183339 > high 36918337032892872 > spanned 262144 > present 262144 > managed 18446744073709533486 > 6. Do anything that requires some memory (e.g., inflate the balloon some > more). The OOM goes crazy and the system crashes > [ 238.324946] Out of memory: Killed process 537 (login) total-vm:27584kB, anon-rss:860kB, file-rss:0kB, shmem-rss:00 > [ 238.338585] systemd invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0 > [ 238.339420] CPU: 0 PID: 1 Comm: systemd Tainted: G D W 5.4.0-next-20191204+ #75 > [ 238.340139] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu4 > [ 238.341121] Call Trace: > [ 238.341337] dump_stack+0x8f/0xd0 > [ 238.341630] dump_header+0x61/0x5ea > [ 238.341942] oom_kill_process.cold+0xb/0x10 > [ 238.342299] out_of_memory+0x24d/0x5a0 > [ 238.342625] __alloc_pages_slowpath+0xd12/0x1020 > [ 238.343024] __alloc_pages_nodemask+0x391/0x410 > [ 238.343407] pagecache_get_page+0xc3/0x3a0 > [ 238.343757] filemap_fault+0x804/0xc30 > [ 238.344083] ? ext4_filemap_fault+0x28/0x42 > [ 238.344444] ext4_filemap_fault+0x30/0x42 > [ 238.344789] __do_fault+0x37/0x1a0 > [ 238.345087] __handle_mm_fault+0x104d/0x1ab0 > [ 238.345450] handle_mm_fault+0x169/0x360 > [ 238.345790] do_user_addr_fault+0x20d/0x490 > [ 238.346154] do_page_fault+0x31/0x210 > [ 238.346468] async_page_fault+0x43/0x50 > [ 238.346797] RIP: 0033:0x7f47eba4197e > [ 238.347110] Code: Bad RIP value. > [ 238.347387] RSP: 002b:00007ffd7c0c1890 EFLAGS: 00010293 > [ 238.347834] RAX: 0000000000000002 RBX: 000055d196a20a20 RCX: 00007f47eba4197e > [ 238.348437] RDX: 0000000000000033 RSI: 00007ffd7c0c18c0 RDI: 0000000000000004 > [ 238.349047] RBP: 00007ffd7c0c1c20 R08: 0000000000000000 R09: 0000000000000033 > [ 238.349660] R10: 00000000ffffffff R11: 0000000000000293 R12: 0000000000000001 > [ 238.350261] R13: ffffffffffffffff R14: 0000000000000000 R15: 00007ffd7c0c18c0 > [ 238.350878] Mem-Info: > [ 238.351085] active_anon:3121 inactive_anon:51 isolated_anon:0 > [ 238.351085] active_file:12 inactive_file:7 isolated_file:0 > [ 238.351085] unevictable:0 dirty:0 writeback:0 unstable:0 > [ 238.351085] slab_reclaimable:5565 slab_unreclaimable:10170 > [ 238.351085] mapped:3 shmem:111 pagetables:155 bounce:0 > [ 238.351085] free:720717 free_pcp:2 free_cma:0 > [ 238.353757] Node 0 active_anon:12484kB inactive_anon:204kB active_file:48kB inactive_file:28kB unevictable:0kB iss > [ 238.355979] Node 0 DMA free:11556kB min:36kB low:48kB high:60kB reserved_highatomic:0KB active_anon:152kB inactivB > [ 238.358345] lowmem_reserve[]: 0 2955 2884 2884 2884 > [ 238.358761] Node 0 DMA32 free:2677864kB min:7004kB low:10028kB high:13052kB reserved_highatomic:0KB active_anon:0B > [ 238.361202] lowmem_reserve[]: 0 0 72057594037927865 72057594037927865 72057594037927865 > [ 238.361888] Node 0 Normal free:193448kB min:99395541895224kB low:73886371836733356kB high:147673348131571488kB reB > [ 238.364765] lowmem_reserve[]: 0 0 0 0 0 > [ 238.365101] Node 0 DMA: 7*4kB (U) 5*8kB (UE) 6*16kB (UME) 2*32kB (UM) 1*64kB (U) 2*128kB (UE) 3*256kB (UME) 2*512B > [ 238.366379] Node 0 DMA32: 0*4kB 1*8kB (U) 2*16kB (UM) 2*32kB (UM) 2*64kB (UM) 1*128kB (U) 1*256kB (U) 1*512kB (U)B > [ 238.367654] Node 0 Normal: 1985*4kB (UME) 1321*8kB (UME) 844*16kB (UME) 524*32kB (UME) 300*64kB (UME) 138*128kB (B > [ 238.369184] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB > [ 238.369915] 130 total pagecache pages > [ 238.370241] 0 pages in swap cache > [ 238.370533] Swap cache stats: add 0, delete 0, find 0/0 > [ 238.370981] Free swap = 0kB > [ 238.371239] Total swap = 0kB > [ 238.371488] 1048445 pages RAM > [ 238.371756] 0 pages HighMem/MovableOnly > [ 238.372090] 306992 pages reserved > [ 238.372376] 0 pages cma reserved > [ 238.372661] 0 pages hwpoisoned > > In another instance (older kernel), I was able to observe this > (negative page count :/): > [ 180.896971] Offlined Pages 32768 > [ 182.667462] Offlined Pages 32768 > [ 184.408117] Offlined Pages 32768 > [ 186.026321] Offlined Pages 32768 > [ 187.684861] Offlined Pages 32768 > [ 189.227013] Offlined Pages 32768 > [ 190.830303] Offlined Pages 32768 > [ 190.833071] Built 1 zonelists, mobility grouping on. Total pages: -36920272750453009 > > In another instance (older kernel), I was no longer able to start any > process: > [root@vm ~]# [ 214.348068] Offlined Pages 32768 > [ 215.973009] Offlined Pages 32768 > cat /proc/meminfo > -bash: fork: Cannot allocate memory > [root@vm ~]# cat /proc/meminfo > -bash: fork: Cannot allocate memory > > Fix it by properly adjusting the managed page count when migrating if > the zone changed. The managed page count of the zones now looks after > unplug of the DIMM (and after deflating the balloon) just like before > inflating the balloon (and plugging+onlining the DIMM). > > We'll temporarily modify the totalram page count. If this ever becomes a > problem, we can fine tune by providing helpers that don't touch > the totalram pages (e.g., adjust_zone_managed_page_count()). > > Reported-by: Yumei Huang > Fixes: 3dcc0571cd64 ("mm: correctly update zone->managed_pages") > Cc: # v3.11+ > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > Cc: Jiang Liu > Cc: Andrew Morton > Cc: virtualization@lists.linux-foundation.org > Signed-off-by: David Hildenbrand > --- > > v1 -> v2: > - Adjust count before enquing newpage (and it possibly gets free form the > balloon) > - Check if the zone changed > > --- > drivers/virtio/virtio_balloon.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 15b7f1d8c334..3078e1ac2a8f 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -722,6 +722,13 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, > > get_page(newpage); /* balloon reference */ > > + /* fixup the managed page count (esp. of the zone) */ /* * When we migrate to a different zone, we have to adjust the managed * page count of both involved zones. */ as requested by Michael. @Michael, if there are no further comments, shall I resend? -- Thanks, David / dhildenb