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 9704CC25B75 for ; Thu, 6 Jun 2024 09:41:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0671E6B0092; Thu, 6 Jun 2024 05:41:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 017296B0098; Thu, 6 Jun 2024 05:41:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DABCC6B009A; Thu, 6 Jun 2024 05:41:18 -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 BD62B6B0092 for ; Thu, 6 Jun 2024 05:41:18 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 6BC2FC1474 for ; Thu, 6 Jun 2024 09:41:18 +0000 (UTC) X-FDA: 82199970636.22.82E9174 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf21.hostedemail.com (Postfix) with ESMTP id 1C04D1C0014 for ; Thu, 6 Jun 2024 09:41:15 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Dw3lUjKK; spf=pass (imf21.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=1717666876; 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=sDuQFsGapZ5dAq2VQ6Agr+wNPKN/yhAr1BOmKnlpkcE=; b=jG/9vEuycI+YviLYXFwjpG5FF1scHvi99/78V6NZokQRlg8GtOfB93BfXA2kg5pIc++DOD N0ZqCdGYkfdn0rSWKjDOX/FZF2R76UdhM28UqpW8Z3aydBeX6GY6kXBdX9bTo//BIwRF10 NEkViYNbCKPKjSpMwS/ETBhtIje/T+w= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1717666876; a=rsa-sha256; cv=none; b=79RXXRRCbVaYJjAdHdTcso+ZDZN6jw39GUg1NsJw3I0XMWwR+ow0PeM3u8zF6N+3VCCRqT 9Y9FAdB9c8jQ7epkXptJAiRytby2PSyS1MPxMpfOSZzA2R2KIUDP3dmyD6Sl2QdK4jqqYo ZO7ZJFcseqJ32+9pDn0S5KiseMu6qHc= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Dw3lUjKK; spf=pass (imf21.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 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717666875; 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=sDuQFsGapZ5dAq2VQ6Agr+wNPKN/yhAr1BOmKnlpkcE=; b=Dw3lUjKK2OSxvwQZhdkakYlwq2LFJ/5Lm5GCbkv3bpo60GsBc6u0Swurd3I7LeRkSkecgU aobzQc+J3ZBEHyHMxv6+wSQrU6zf6HLe8pSd22HD7ZbknjTFRtVwOw+Sm+ESPMDHz1KjP9 NqSfJ8J7BH3PTR3E5ysL+6Nd8OYpQWU= Received: from mail-lf1-f72.google.com (mail-lf1-f72.google.com [209.85.167.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-203-DRSqVcF9NyygAbXECwklDg-1; Thu, 06 Jun 2024 05:41:13 -0400 X-MC-Unique: DRSqVcF9NyygAbXECwklDg-1 Received: by mail-lf1-f72.google.com with SMTP id 2adb3069b0e04-52b84eb911dso503377e87.0 for ; Thu, 06 Jun 2024 02:41:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717666872; x=1718271672; 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=sDuQFsGapZ5dAq2VQ6Agr+wNPKN/yhAr1BOmKnlpkcE=; b=V7gz91cCYLaTzxSUKZY1gIJZfFMYhpVeuLrNW6S6R8aXqah3ic4b3AoTU8sjdaExHa UylnK75C0HWEBCLcQCp02Bypx180kcmKBHTK910G6uN3kDUNQ4xFe3BwM670BN4JfiPk I9WiIcrU8JPuQ7uGQp58FOeAEep6g7SxlVEZYA0qozVMv3FzZoUcvOkTQtoc2DG+WxQf YvyVgEToI0joeUerHUL7eP39l6vbE1yvEJXdj+GGTUIKH/Mh1HzukqNpNTu79JWv/OQv IafxWwafCXhXjpFIBHoO3G+UXMgXT+QSJ4R0NUamYSorEeUZODkUxqcIOWCB1FdnAZHg cg4Q== X-Forwarded-Encrypted: i=1; AJvYcCWaZZ6B3ALAiPywwgpyX2dgJivZRn1PgCtCgMDMZaXankxWHBZsLiHS4yTeP3MHFzQUm/qJAuK/9KAEqW8hlUNwbmQ= X-Gm-Message-State: AOJu0YyURZQ61dXJmDsTJ1J2MdVl1W+QJYt3u1EAbVIEVlJ51dSTWl3B FWl8hcgyfcOChZgbfCtZ85tawBwFhZeu7yag4OgF/vZ0oFJmG/s1iBGtVwU9HTGosAVsRdSs89e Nej6u/QiF293txiMEkubyAnACMFqDDG25vCGJtMCjgoOQCryJ+esgHjMw X-Received: by 2002:a19:a40a:0:b0:52b:aa2f:d89b with SMTP id 2adb3069b0e04-52bab4fc5c9mr2758005e87.68.1717666872103; Thu, 06 Jun 2024 02:41:12 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFhLqsJXiIpJ9ZW7HW04hpVTkrfSK7URSEN5bAqF0lpzCT8Uw/WRp+1uI1wUYbaEqt8GWmWAQ== X-Received: by 2002:a19:a40a:0:b0:52b:aa2f:d89b with SMTP id 2adb3069b0e04-52bab4fc5c9mr2757990e87.68.1717666871651; Thu, 06 Jun 2024 02:41:11 -0700 (PDT) Received: from ?IPV6:2003:cb:c710:8800:a73c:ec5b:c02c:5e0b? (p200300cbc7108800a73cec5bc02c5e0b.dip0.t-ipconnect.de. [2003:cb:c710:8800:a73c:ec5b:c02c:5e0b]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4215c1aa2easm15655555e9.12.2024.06.06.02.41.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Jun 2024 02:41:11 -0700 (PDT) Message-ID: <2a6a1b50-e711-42c2-91f4-42881a6057e9@redhat.com> Date: Thu, 6 Jun 2024 11:41:09 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/3] mm/rmap: integrate PMD-mapped folio splitting into pagewalk loop To: Lance Yang Cc: akpm@linux-foundation.org, willy@infradead.org, sj@kernel.org, baolin.wang@linux.alibaba.com, maskray@google.com, ziy@nvidia.com, ryan.roberts@arm.com, 21cnbao@gmail.com, mhocko@suse.com, fengwei.yin@intel.com, zokeefe@google.com, shy828301@gmail.com, xiehuan09@gmail.com, libang.li@antgroup.com, wangkefeng.wang@huawei.com, songmuchun@bytedance.com, peterx@redhat.com, minchan@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20240521040244.48760-1-ioworker0@gmail.com> <20240521040244.48760-3-ioworker0@gmail.com> <758f7be7-c17e-46d1-879f-83340ec85749@redhat.com> <5a728148-ed93-4d68-a86f-9be3612dedbb@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-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Stat-Signature: qh8ap15frxuc66zz4iajam3jaana696s X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 1C04D1C0014 X-HE-Tag: 1717666875-68334 X-HE-Meta: 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 7E2P14Sz 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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 06.06.24 11:38, Lance Yang wrote: > On Thu, Jun 6, 2024 at 4:06 PM David Hildenbrand wrote: >> >> On 06.06.24 10:01, David Hildenbrand wrote: >>> On 06.06.24 05:55, Lance Yang wrote: >>>> On Wed, Jun 5, 2024 at 10:28 PM David Hildenbrand wrote: >>>>> >>>>> On 05.06.24 16:20, Lance Yang wrote: >>>>>> Hi David, >>>>>> >>>>>> On Wed, Jun 5, 2024 at 8:46 PM David Hildenbrand wrote: >>>>>>> >>>>>>> On 21.05.24 06:02, Lance Yang wrote: >>>>>>>> In preparation for supporting try_to_unmap_one() to unmap PMD-mapped >>>>>>>> folios, start the pagewalk first, then call split_huge_pmd_address() to >>>>>>>> split the folio. >>>>>>>> >>>>>>>> Since TTU_SPLIT_HUGE_PMD will no longer perform immediately, we might >>>>>>>> encounter a PMD-mapped THP missing the mlock in the VM_LOCKED range during >>>>>>>> the page walk. It’s probably necessary to mlock this THP to prevent it from >>>>>>>> being picked up during page reclaim. >>>>>>>> >>>>>>>> Suggested-by: David Hildenbrand >>>>>>>> Suggested-by: Baolin Wang >>>>>>>> Signed-off-by: Lance Yang >>>>>>>> --- >>>>>>> >>>>>>> [...] again, sorry for the late review. >>>>>> >>>>>> No worries at all, thanks for taking time to review! >>>>>> >>>>>>> >>>>>>>> diff --git a/mm/rmap.c b/mm/rmap.c >>>>>>>> index ddffa30c79fb..08a93347f283 100644 >>>>>>>> --- a/mm/rmap.c >>>>>>>> +++ b/mm/rmap.c >>>>>>>> @@ -1640,9 +1640,6 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, >>>>>>>> if (flags & TTU_SYNC) >>>>>>>> pvmw.flags = PVMW_SYNC; >>>>>>>> >>>>>>>> - if (flags & TTU_SPLIT_HUGE_PMD) >>>>>>>> - split_huge_pmd_address(vma, address, false, folio); >>>>>>>> - >>>>>>>> /* >>>>>>>> * For THP, we have to assume the worse case ie pmd for invalidation. >>>>>>>> * For hugetlb, it could be much worse if we need to do pud >>>>>>>> @@ -1668,20 +1665,35 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, >>>>>>>> mmu_notifier_invalidate_range_start(&range); >>>>>>>> >>>>>>>> while (page_vma_mapped_walk(&pvmw)) { >>>>>>>> - /* Unexpected PMD-mapped THP? */ >>>>>>>> - VM_BUG_ON_FOLIO(!pvmw.pte, folio); >>>>>>>> - >>>>>>>> /* >>>>>>>> * If the folio is in an mlock()d vma, we must not swap it out. >>>>>>>> */ >>>>>>>> if (!(flags & TTU_IGNORE_MLOCK) && >>>>>>>> (vma->vm_flags & VM_LOCKED)) { >>>>>>>> /* Restore the mlock which got missed */ >>>>>>>> - if (!folio_test_large(folio)) >>>>>>>> + if (!folio_test_large(folio) || >>>>>>>> + (!pvmw.pte && (flags & TTU_SPLIT_HUGE_PMD))) >>>>>>>> mlock_vma_folio(folio, vma); > > Should we still keep the '!pvmw.pte' here? Something like: > > if (!folio_test_large(folio) || !pvmw.pte) > mlock_vma_folio(folio, vma); I was wondering the same the whole time ... > > We can mlock the THP to prevent it from being picked up during page reclaim. > > David, I’d like to hear your thoughts on this ;) but I think there is no need to for now, in the context of your patchset. :) -- Cheers, David / dhildenb