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 53A85C52D6F for ; Tue, 6 Aug 2024 09:24:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A04B06B007B; Tue, 6 Aug 2024 05:24:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9B4406B0082; Tue, 6 Aug 2024 05:24:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 82DAD6B0083; Tue, 6 Aug 2024 05:24:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 64A876B007B for ; Tue, 6 Aug 2024 05:24:27 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 0792DA88AC for ; Tue, 6 Aug 2024 09:24:27 +0000 (UTC) X-FDA: 82421284974.29.6494421 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf18.hostedemail.com (Postfix) with ESMTP id BA8E51C000D for ; Tue, 6 Aug 2024 09:24:24 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ci9mi5gU; spf=pass (imf18.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1722936234; 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=x0bbPb+iT7QK5TXH+pBWd/vn2pYSO+i1p4cWJD4AOA4=; b=Jru7brAO5dqa/GR1ylDqLlNJg/94U+2RRRL4ECOlf/ks9iV45nnjZ5OGbgdXeCFp+mSPy3 2HS/EzyVfwxPpTEzh32yrMUqwtDIIsrEQq0t8EluNIuPU2s28D8uQPqfeWINdpInpR6WwB ywwXwQWeOtk2e9nwhKBdRPkPCaT1KxA= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=ci9mi5gU; spf=pass (imf18.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1722936234; a=rsa-sha256; cv=none; b=ax+md1wVhUroUcSQ6InW0hbM1ggh6i29knTdcRrRoFT487kcqB3H30G0wrqum6uXonbIe8 YccH6u0+RxS5JuJCES/+UZdQk8LXDwIo6MLCWnjoSx2fbQN04mdOHo+4CbkSi5JiozuawS NQrUIZIf0kPNqr5DUmuiv4anB/d1uWk= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722936264; 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=x0bbPb+iT7QK5TXH+pBWd/vn2pYSO+i1p4cWJD4AOA4=; b=ci9mi5gUi6sInKbapZSvApefFm48GWuai9/okyl81rX5UUnvQo7N52b3F2ZBzuueYqqu2I hhkvB8+ASymKScRTfQIzBfleJ8uDrA73yEkDbqkIiERBj+TyBRB558c6yUpHXxdrJficLl 8q78tqtBUKvSndJBp5+b8gpA3mEcz38= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-261-tMyfYLmnOMq9HFkMgcaKIg-1; Tue, 06 Aug 2024 05:24:21 -0400 X-MC-Unique: tMyfYLmnOMq9HFkMgcaKIg-1 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-36873a449dfso3211522f8f.0 for ; Tue, 06 Aug 2024 02:24:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722936261; x=1723541061; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from: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=x0bbPb+iT7QK5TXH+pBWd/vn2pYSO+i1p4cWJD4AOA4=; b=aZ21xiR3muorvTlZDFTu7MlL0fqHfdsBOjAqKUlBx4ZlhEFP0xowLLLT8SqbuHmqyP SlXCxCBfRmt5Lb0MdZo4qCz1FGB08YjzPbbQbwAsgH8Zb3IRrMCY2I7kukGs9oe2+Qb9 tTZaeMWb+8ONXEa5nfK4H+uXLmdyk2Hrh3rbxpZ0AEVSXThGWboipvg5Foa2UX6jdntU I6+HzXqxUiKTlTgWo85Y/CHjKWPI4Mwp1fooxXfwz2wSae6oBd4PJ60zNOBwny9maVUp 8sJEdOxBw893eLdtU1uKQPrGInQ7oTbYGfB+eN/cH4Nxek3YplEwn9Dq9GnL4W8wajvy XCjQ== X-Forwarded-Encrypted: i=1; AJvYcCVnQ8GQmLNV6/GkdoyfP09+fB8/BPoftkIzKBh+pzmvvUBPt0JkLr27Zk4WZpV5bo1WZFIjP1aajqYW6T9gurSmLxg= X-Gm-Message-State: AOJu0Yy8OQ7xZKp2H/GtyllD1KgIR4BBi7T1RzkFBqyghJDGuOGNVCQo EiPDmkdE6+Glgg7W8KPH9jJ4GJEvPsv8sGWakkfoUZQRAuaA8xfUbd24FvooKVKwbXLYuAGMTiu 9qntgNDNsAjnACTTBgXmnve0X90Qe53LETSe+d7516NYTXOBo X-Received: by 2002:a05:6000:2a2:b0:36b:a5ac:7a with SMTP id ffacd0b85a97d-36bb359d36emr14122324f8f.7.1722936260774; Tue, 06 Aug 2024 02:24:20 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFiyIUQ2HwIK0Z3xZ++gMfiaAZ3PPkWlPia1v/9tEIGzqx2i+ge2C1GSsLcyyg+8rL/W+mdWw== X-Received: by 2002:a05:6000:2a2:b0:36b:a5ac:7a with SMTP id ffacd0b85a97d-36bb359d36emr14122291f8f.7.1722936260213; Tue, 06 Aug 2024 02:24:20 -0700 (PDT) Received: from ?IPV6:2003:cb:c73f:8500:f83c:3602:5300:88af? (p200300cbc73f8500f83c3602530088af.dip0.t-ipconnect.de. [2003:cb:c73f:8500:f83c:3602:5300:88af]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-428e6e3c0b7sm171278555e9.23.2024.08.06.02.24.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 06 Aug 2024 02:24:19 -0700 (PDT) Message-ID: Date: Tue, 6 Aug 2024 11:24:18 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/4] mm: memory_hotplug: check hwpoisoned page firstly in do_migrate_range() To: Kefeng Wang , Andrew Morton Cc: Oscar Salvador , Miaohe Lin , Naoya Horiguchi , linux-mm@kvack.org References: <20240725011647.1306045-1-wangkefeng.wang@huawei.com> <20240725011647.1306045-3-wangkefeng.wang@huawei.com> <0ff4a4ac-7b7b-4e07-a5da-a4c4e41438d6@redhat.com> <7eb9436d-b4e5-4be1-adce-aa07cc493679@huawei.com> <4e693aa6-d742-4fe7-bd97-3d375f96fcfa@huawei.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: <4e693aa6-d742-4fe7-bd97-3d375f96fcfa@huawei.com> X-Mimecast-Spam-Score: 0 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: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: BA8E51C000D X-Stat-Signature: 6yx6j18y7f7sbnpigqnr4wyyugci988i X-HE-Tag: 1722936264-96411 X-HE-Meta: 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 +jYjJRig 74crDnTDzo5IhMrVHB+JsCJWq/qoFVsHB7VS1JstLaNFFBDlzt1Y8o9kE5/PWSjXSLR7JAr+0iM4nzMEgtcgDqXnvMZ3ZGYN/Kjixf17rBFRZ1EhKZ4yAQerOQ60/jjNDruXG84M3y//0rBe0jFPdQB4Od+9MpEPMTWwvTju+PWuGEkN9cotciO7ZXXXaki74Fm0L6+YTpNKfWyEKc2Rx3fCoEXS7f4+dN+fXjn13iK3/6Cb1uXhwibL9ZP1XcaWWnn9PBvyzRFLHWgs8NheBDikRAY7b9vQln394rVnlR6WkS88fDHb0kChfy59zMOy7ewa4Ia1VUrhHbhxjHdRqMxC07WEMC5pGeOXz+fbR3zQ1dy0X58D691I6KUl3byiqiPge1E4ldNmod79qctIQEb6hRyfiTF1MIlY2XuzWS5wC/m1MXRnAVAEGOv0pLxaPLCx2/GJ1Boi/xvMTOlUgwRI0ewF2qzoF2lsC X-Bogosity: Ham, tests=bogofilter, spamicity=0.000019, 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 06.08.24 05:44, Kefeng Wang wrote: > Hi David, I have some question, > > On 2024/8/2 16:02, Kefeng Wang wrote: >> > ... >>>>            */ >>>> -        if (PageHWPoison(page)) { >>>> +        if (unlikely(PageHWPoison(page))) { >>>> +            folio = page_folio(page); >>>> + >>>>               if (WARN_ON(folio_test_lru(folio))) >>>>                   folio_isolate_lru(folio); >>>> + >>>>               if (folio_mapped(folio)) >>>> -                try_to_unmap(folio, TTU_IGNORE_MLOCK); >>>> +                unmap_posioned_folio(folio, TTU_IGNORE_MLOCK); >>>> + >>>> +            if (folio_test_large(folio)) >>>> +                pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1; >>>>               continue; >>>>           } >>>> +        if (PageHuge(page)) { >>>> +            pfn = page_to_pfn(head) + compound_nr(head) - 1; >>>> +            isolate_hugetlb(folio, &source); >>>> +            continue; >>>> +        } else if (PageTransHuge(page)) > > If the page is a tail page, we will BUG_ON(DEBUG_VM enabled) here, but > it seems that we don't guarantee the page won't be a tail page. Maybe at some point we might want to remove these sanity checks or have explicit, expected-to-be-racy folio functions. Like folio_test_hugetlb_racy(), folio_test_large_racy(), folio_nr_pages_racy(). Because the VM_DEBUG checks for folio_test_large() etc. actually make sense in other context where we know that concurrent splitting is impossible. But maybe part of the puzzle will be in the future that we want to do a RCU read lock here and perform freeing/splitting under RCU, when we'll also have to alloc/free the "struct folio". > >>>> +            pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; > > thp_nr_pages() need a head page, I think it should use head here, so we > can directly use folio_nr_pages(). > >>> >>> If we can use a folio in the PageHWPoison() case, can we use one here >>> as well? I know that it's all unreliable when not holding a folio >>> reference, and we have to be a bit careful. >> >> Using a folio here is part of patch4, I want to unify hugetlb/thp(or >> large folio) with "pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1" >> when large folio after get a ref. > > Think it again, even the folio don't hold a ref(splitting concurrently > or something else), folio_nr_pages return incorrect, it won't cause > issue since we will loop and find movable pages again in > scan_movable_pages() and try to isolate pages, so directly use > > if (folio_test_large(folio)) { > pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1; > if (folio_test_hugetlb(folio)) > isolate_hugetlb(folio, &source); > } Likely we should add a comment here that a large folio might get split concurrently and that folio_nr_pages() might read garbage. But out loop should handle that and we would revisit the split folio later. -- Cheers, David / dhildenb