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 3573DC677C4 for ; Wed, 11 Jun 2025 09:20:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BC31B6B008A; Wed, 11 Jun 2025 05:20:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B73E46B008C; Wed, 11 Jun 2025 05:20:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A3B716B0092; Wed, 11 Jun 2025 05:20:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 86C1E6B008A for ; Wed, 11 Jun 2025 05:20:11 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 440D8BA7C6 for ; Wed, 11 Jun 2025 09:20:11 +0000 (UTC) X-FDA: 83542573422.27.03DB50D Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf07.hostedemail.com (Postfix) with ESMTP id B8EFB40009 for ; Wed, 11 Jun 2025 09:20:08 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=UiOxOdVR; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf07.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749633609; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8LXQEVwg1eeKuNQ63vYHABUXX1DccHkL97J3fslOSz4=; b=vekrd00B9QK14wvIhdw+cxWuWzhh9TwwWV2ei1dwcQDPg3L8vXgMmXW+qNEfAgd6V9wdfa lNavHmycfF6/qBmdFkaI2eHP/hNDdVCVRWyXfDXGQhvjOluhitbjbKx25S3vP9h179Vgk5 6JHUs/SUTHucriAEwXmfgdTbecSG5Lo= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=UiOxOdVR; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf07.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1749633609; a=rsa-sha256; cv=none; b=8g7hyndC2aJEJoWI8iy1y1lER1QrmfYMF/iMSydQFzSKOPODUE270m4YPnvOO04WwTRGDQ w9aIEa++gIPwgcJxhPFQIlv17KtodHJ4hcLyWumGT2V24rsfHC37mDDq/v3ut8qlrNhP6o 0x/rQr8nuIe3R3BZfgerlOwd7on9gDM= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749633608; 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=8LXQEVwg1eeKuNQ63vYHABUXX1DccHkL97J3fslOSz4=; b=UiOxOdVRcli74QE339jIrTNlOF99avpa/pmUS6Rfp4TOpAu6HhncA9mdEzrfTN5U2T2Xu/ GdTvNQwO/SDhbFwPHDrgzf8K6JvIYaNnJcn7oMedbyFI4PpE4FK/T7O7fLOAD+/lfTMZ9Q taFU9jeBfRD4ME0KEyVAiKxKEsWlT24= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-140-xd7xempiNr6Kp_7LMpk45Q-1; Wed, 11 Jun 2025 05:20:04 -0400 X-MC-Unique: xd7xempiNr6Kp_7LMpk45Q-1 X-Mimecast-MFC-AGG-ID: xd7xempiNr6Kp_7LMpk45Q_1749633603 Received: by mail-ej1-f69.google.com with SMTP id a640c23a62f3a-ade81d27cddso131372666b.0 for ; Wed, 11 Jun 2025 02:20:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749633603; x=1750238403; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=8LXQEVwg1eeKuNQ63vYHABUXX1DccHkL97J3fslOSz4=; b=eY4YpBw+oCWCtlgMb/A8yxCWQqaam7qb3XNQ/CtoiI6XH1btCgn4bpAgHl/pvBTEmg VE1yLfen1hJs0zTRq1WNfJBM2OJXB+W4x6XuGTutlA7MCdVqBLWHzvhFmY3cFn61yDS+ Vpxc0lBgHEaGKv/TWwTPKpz9rKtJ0jWktK3OOubcSbODRiKc7j3gjL/bXK6fJpv1HDWX r8GbiiWYiKqoKiYwB/6NjMC4jHxHiWpcMjvxe2D3M1c9O9cWTL0JNo0Kso1627JoDRhM WrhYNwMg9DCJoV5ZnKPk1ouI2Eh2HWaIupDP7p2AwWI+DIVq6d0Hd4MBbbb5wCpgGm1n PmrA== X-Gm-Message-State: AOJu0YwknoHaifu06y183uH2sPOSqC8VsQG1nHeeMyJ0K36YQ5MO6Rxi jqwuVW9Wq4foHrVgEtpq81I/Ho2fjZNw1Yy0RdZ/UgheS2S/WJ44ZNVBqdbFL64YLwOPxvUz+0s lLfh7j6pw5Zp38Pu3ztIyiPwOH+GJg2iDJMeBVd4B3ENr/I7MPwqK X-Gm-Gg: ASbGncvpt4eykvVcCscWJyBGrgG3J4LO/7EXEe8eE480b0x5ly991pLrYj9IkNfybSm k/t8xaE6uYuJ1pPsAXlPYKXAXIIg+OeUV2OJmTpHv+tuEckHGmol7TRLZB7dMRlrbbL2tUyDRHF YKn9q4xj0o0oA4xrjcOiaTDdVz+8yc+cjrEiv7c8N/cdADZZlHdiQjOUVsCqv54czF5WD/LgECY cW1u75P7tIItdyF+2V6t6EjFd4siU9T9h14bY1Mgc7bHPpRz4FkGTVG3/6/y5kIya0X8L+MwgGE 7R6k2PDzxZ3VaN/HzuXqbrXZHnezWhxvA05LJiCNvLrC X-Received: by 2002:a17:907:a4d:b0:ad4:8ec1:8fcf with SMTP id a640c23a62f3a-ade8977931emr248967566b.46.1749633603234; Wed, 11 Jun 2025 02:20:03 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGYIZo1nYKQ+bXE/lBStyjkIb6xe4jkLKyPu14TUfmyKPc34qtu+o3+du1E4eo0FPVuTtmVEw== X-Received: by 2002:a17:907:a4d:b0:ad4:8ec1:8fcf with SMTP id a640c23a62f3a-ade8977931emr248964066b.46.1749633602766; Wed, 11 Jun 2025 02:20:02 -0700 (PDT) Received: from [10.32.64.156] (nat-pool-muc-t.redhat.com. [149.14.88.26]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ade1d7547a2sm857294966b.23.2025.06.11.02.20.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 11 Jun 2025 02:20:02 -0700 (PDT) Message-ID: Date: Wed, 11 Jun 2025 11:20:01 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list To: Jinjiang Tu , akpm@linux-foundation.org, linmiaohe@huawei.com Cc: linux-mm@kvack.org, wangkefeng.wang@huawei.com, Zi Yan References: <20250611074643.250837-1-tujinjiang@huawei.com> <1f0c7d73-b7e2-4ee9-8050-f23c05e75e8b@redhat.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW 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/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz 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+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/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 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 7RH4P4vfAp_5MPdFkyG0QPncWZTGssbkDD14FBANwfY_1749633603 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: B8EFB40009 X-Stat-Signature: 6zruced6pgntpruineqz3ftccjekunjq X-Rspam-User: X-HE-Tag: 1749633608-597031 X-HE-Meta: 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 /rqzxY/3 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 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: List-Subscribe: List-Unsubscribe: On 11.06.25 11:00, Jinjiang Tu wrote: > > 在 2025/6/11 16:35, David Hildenbrand 写道: >> On 11.06.25 10:29, Jinjiang Tu wrote: >>> >>> 在 2025/6/11 15:59, David Hildenbrand 写道: >>>> On 11.06.25 09:46, Jinjiang Tu wrote: >>>>> In shrink_folio_list(), the hwpoisoned folio may be large folio, which >>>>> can't be handled by unmap_poisoned_folio(). >>>>> >>>>> Since UCE is rare in real world, and race with reclaimation is more >>>>> rare, >>>>> just skipping the hwpoisoned large folio is enough. memory_failure() >>>>> will >>>>> handle it if the UCE is triggered again. >>>>> >>>>> Fixes: 1b0449544c64 ("mm/vmscan: don't try to reclaim hwpoison folio") >>>> >>>> Please also add >>>> >>>> Closes: >>>> >>>> with a link to the report >>> Thanks, I will add it. >>>> >>>>> Reported-by: syzbot+3b220254df55d8ca8a61@syzkaller.appspotmail.com >>>>> Signed-off-by: Jinjiang Tu >>>>> --- >>>>>    mm/vmscan.c | 8 ++++++++ >>>>>    1 file changed, 8 insertions(+) >>>>> /home/tujinjiang/hulk-repo/hulk/mm/mempolicy.c >>>>> diff --git a/mm/vmscan.c b/mm/vmscan.c >>>>> index b6f4db6c240f..3a4e8d7419ae 100644 >>>>> --- a/mm/vmscan.c >>>>> +++ b/mm/vmscan.c >>>>> @@ -1131,6 +1131,14 @@ static unsigned int shrink_folio_list(struct >>>>> list_head *folio_list, >>>>>                goto keep; >>>>>              if (folio_contain_hwpoisoned_page(folio)) { >>>>> +            /* >>>>> +             * unmap_poisoned_folio() can't handle large >>>>> +             * folio, just skip it. memory_failure() will >>>>> +             * handle it if the UCE is triggered again. >>>>> +             */ >>>>> +            if (folio_test_large(folio)) >>>>> +                goto keep_locked; >>>>> + >>>>>                unmap_poisoned_folio(folio, folio_pfn(folio), false); >>>>>                folio_unlock(folio); >>>>>                folio_put(folio); >>>> >>>> Why not handle that in unmap_poisoned_folio() to make that limitation >>>> clear and avoid? >>> I tried to put the check in unmap_poisoned_folio(), but it still exists >>> other issues. >> >> >> >>> The calltrace in v6.6 kernel: >>> >>> Unable to handle kernel paging request at virtual address >>> fbd5200000000024 >>> KASAN: maybe wild-memory-access in range >>> [0xdead000000000120-0xdead000000000127] >>> pc : __list_add_valid_or_report+0x50/0x158 lib/list_debug.c:32 >>> lr : __list_add_valid include/linux/list.h:88 [inline] >>> lr : __list_add include/linux/list.h:150 [inline] >>> lr : list_add_tail include/linux/list.h:183 [inline] >>> lr : lru_add_page_tail.constprop.0+0x4ac/0x640 mm/huge_memory.c:3187 >>> Call trace: >>>    __list_add_valid_or_report+0x50/0x158 lib/list_debug.c:32 >>>    __list_add_valid include/linux/list.h:88 [inline] >>>    __list_add include/linux/list.h:150 [inline] >>>    list_add_tail include/linux/list.h:183 [inline] >>>    lru_add_page_tail.constprop.0+0x4ac/0x640 mm/huge_memory.c:3187 >>>    __split_huge_page_tail.isra.0+0x344/0x508 mm/huge_memory.c:3286 >>>    __split_huge_page+0x244/0x1270 mm/huge_memory.c:3317 >>>    split_huge_page_to_list_to_order+0x1038/0x1620 mm/huge_memory.c:3625 >>>    split_folio_to_list_to_order include/linux/huge_mm.h:638 [inline] >>>    split_folio_to_order include/linux/huge_mm.h:643 [inline] >>>    deferred_split_scan+0x5f8/0xb70 mm/huge_memory.c:3778 >>>    do_shrink_slab+0x2a0/0x828 mm/vmscan.c:927 >>>    shrink_slab_memcg+0x2c0/0x558 mm/vmscan.c:996 >>>    shrink_slab+0x228/0x250 mm/vmscan.c:1075 >>>    shrink_node_memcgs+0x34c/0x6a0 mm/vmscan.c:6630 >>>    shrink_node+0x21c/0x1378 mm/vmscan.c:6664 >>>    shrink_zones.constprop.0+0x24c/0xab0 mm/vmscan.c:6906 >>>    do_try_to_free_pages+0x150/0x880 mm/vmscan.c:6968 >>> >>> >>> The folio is deleted from lru and the folio->lru can't be accessed. If >>> the folio is splitted later, >>> lru_add_split_folio() assumes the folio is on lru. >> >> Not sure if something like the following would be appropriate: >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index b91a33fb6c694..fdd58c8ba5254 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -1566,6 +1566,9 @@ int unmap_poisoned_folio(struct folio *folio, >> unsigned long pfn, bool must_kill) >>         enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON; >>         struct address_space *mapping; >> >> +       if (folio_test_large && !folio_test_hugetlb(folio)) >> +               return -EBUSY; >> + >>         if (folio_test_swapcache(folio)) { >>                 pr_err("%#lx: keeping poisoned page in swap cache\n", >> pfn); >>                 ttu &= ~TTU_HWPOISON; >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index f8dfd2864bbf4..6a3426bc9e9d7 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -1138,7 +1138,8 @@ static unsigned int shrink_folio_list(struct >> list_head *folio_list, >>                         goto keep; >> >>                 if (folio_contain_hwpoisoned_page(folio)) { >> -                       unmap_poisoned_folio(folio, folio_pfn(folio), >> false); >> +                       if (unmap_poisoned_folio(folio, >> folio_pfn(folio), false)){ >> +                               list_add(&folio->lru, &ret_folios); >>                         folio_unlock(folio); >>                         folio_put(folio); >>                         continue; > > The expected behaviour is keeping the folio on lru if > unmap_poisoned_folio fails? Good question, it's a mess. If we keep the LRU bit cleared (kept isolated), we wouldn't have to add it to the list. But now I wonder where deferred_split_scan() would check for the LRU flag? It seems to trylock, to then call split_folio(). In __folio_split(), I don't find any checks for the lru flag ... :( We call lru_add_split_folio() where we VM_BUG_ON_FOLIO(folio_test_lru(new_folio), folio); So now I am confused. > > If so, we should: > > +                       if (unmap_poisoned_folio(folio, > folio_pfn(folio), false)){ > +                               goto keep_locked; > > otherwise, folio_put() is called twice to put ref grabbed from isolation. Good point. Maybe Zi Yan can help. Re-adding them to the LRU if anything goes wrong should work, but I am not sure if that's the right approach. -- Cheers, David / dhildenb