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 0A14BC021BB for ; Mon, 24 Feb 2025 21:05:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E3496B0083; Mon, 24 Feb 2025 16:05:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 86B446B0092; Mon, 24 Feb 2025 16:05:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6BD576B0093; Mon, 24 Feb 2025 16:05:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 460946B0083 for ; Mon, 24 Feb 2025 16:05:01 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id D49C9AF34F for ; Mon, 24 Feb 2025 21:05:00 +0000 (UTC) X-FDA: 83156067960.15.FD28CB2 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf04.hostedemail.com (Postfix) with ESMTP id 70EC040003 for ; Mon, 24 Feb 2025 21:04:58 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=FvMDebIn; spf=pass (imf04.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=1740431098; 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=G9uYUL0lJEpfTP/jqrCc2TxiFlGEyB8SF3wTaZs7RW8=; b=VFOzIzuhNk9h5ShkS+XWxGv6+Ky1YR7o2t+FJFFlb12wbHBOvD6XfUttXnLw9CUBqQqcIs Y2vad+Az5e85KZjbKbEPKz7BWGSaHqrwHw8DsZKRRY4kLXrn+6JlLMDB9962BhBT5PVbjL kXwcK8i3O7ylK4UCpS6C8OgQ7WYJj1w= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=FvMDebIn; spf=pass (imf04.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=1740431098; a=rsa-sha256; cv=none; b=5RC9hjTBJHlHbOTDEAQzyqsHzXqIzIa8BP+EW+shUbrWNLJ+MbpO2O14PpgvCHZl8leuO3 ykKdrcL2V+3dXBhqsdIzUeOf4SKr1OhXOzxB95d2LrATCsLUUS/D0CMjIUCQthBMSz9CWZ 2Q7an/BnQbSGvlLIEOh5fJ3+5UD8+mk= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740431097; 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=G9uYUL0lJEpfTP/jqrCc2TxiFlGEyB8SF3wTaZs7RW8=; b=FvMDebIn3GtqxPJJoQVQtmXg5NBLGb1TRL0BUSIJcJZpxVSKNFSl0E4x0l8xTeYO5B+RsF ICTEjEkIZydoP/4/deIAizEEBviAQZ0E6myA4hp1tUeVnXe8Ei6/tAhK1DKXjxEBW3yTYz ToVpWmSJi35YwF2za8o6eAvmOFEsixE= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-523-LLg96NoQPimRodpeGX6fgA-1; Mon, 24 Feb 2025 16:04:56 -0500 X-MC-Unique: LLg96NoQPimRodpeGX6fgA-1 X-Mimecast-MFC-AGG-ID: LLg96NoQPimRodpeGX6fgA_1740431095 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-38f255d44acso2099989f8f.0 for ; Mon, 24 Feb 2025 13:04:56 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740431095; x=1741035895; 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=G9uYUL0lJEpfTP/jqrCc2TxiFlGEyB8SF3wTaZs7RW8=; b=WZQeLjRfxE0fLu8dVOluEZyAnE2Rp/0yXyu8TAM4FBZoW577qOUJpZYMtdY4wGMPht Cz8I9y5n9rnfC0fd9jMtYBw7jSDle9S27EsuKXppxktTxX/UqfPJrVQBQPHAoL7OyFoG kXOWYS2WicMoHiByaFNfqOi+dcNiFr//u2GvYFD9zOaoMkn8pW6Qi3QlQvCa7F1/96/w qYrsOH8rLE6v2O304f3ixFQer6XI8IF6OTck5romOeEE/neDxdIdFvfrP4rMFTJG3HjD g2eRa11rDoGTjIN5TRKbPaeT7KipUT+g8gdFqXbYRmlcU8bYLpwtRpXyCOh0fqqk+ltI KNEQ== X-Forwarded-Encrypted: i=1; AJvYcCVaVUdzwYvqDpPUljICvMGjlJAUtM4pgcnCXw+Jaoz7S+lF0eggDxWdByznn+TgyVNTk7vdA7fJwg==@kvack.org X-Gm-Message-State: AOJu0YzLOcwivzlOS4tDU09nz+SOLH/cn0YgQpmyuwDhCA1t6QWFabJ1 NFmeQ6RaK4SqXgJxe6IJ9lDK2IKKe6p0EaYbecvGDr7iV2U4ldjvvdYeEOxZYf8049hVvdlXEQ0 /+2e1CE6oJGOuJpR1GxVvWZUuMvD7naty9boH9ykFeytXnZEmrrnSltc5w6w= X-Gm-Gg: ASbGncvJfbmptVcdsXNtyexx1+pQERSYzwtAss1mtFVtiFXn59v2zs6LSxKqdizEHPf 5E8vTzqiCosj57u6B2c0Wv1r2t42iWJEyFLeYQz17K7hjYh+TiY5+swE6tVKSOwWsIbYeEt8Ml7 D2G2yGY6EpGM6V8N3DHjc/x8AVVQWePKJisLjwVdzaAYPvX9NkfHX4OXsSImtoFwDzSX+1hSA8X Ui3HG5a3T6px8aRbjw7sChfxBfwHyqLQU66bbYqBkm1wXe/RK80laa13h5x+EHuCGCCVw95OtI3 Q/llnrZpXB1sF1PqEZH2DZ4GkItLZoCxdCba93Z+uvlHLqdCRmyY3VQEtqkFMiWnyH8Ve4AOwEq HdmCXiRiM74kD/jw/xEFQgC1FTODe8eS9a2nm30tv9JY= X-Received: by 2002:a05:6000:4026:b0:38f:277a:4ecb with SMTP id ffacd0b85a97d-38f6e74f4b7mr12727159f8f.2.1740431095339; Mon, 24 Feb 2025 13:04:55 -0800 (PST) X-Google-Smtp-Source: AGHT+IEe06nX7iFsBC61rd58f1qQXgBlzAj+Cm5rmfwjdF2Zq8d7qwhUsqzdKqy2LGpxicuLB9NP9w== X-Received: by 2002:a05:6000:4026:b0:38f:277a:4ecb with SMTP id ffacd0b85a97d-38f6e74f4b7mr12727146f8f.2.1740431094951; Mon, 24 Feb 2025 13:04:54 -0800 (PST) Received: from ?IPV6:2003:cb:c735:1900:ac8b:7ae5:991f:54fc? (p200300cbc7351900ac8b7ae5991f54fc.dip0.t-ipconnect.de. [2003:cb:c735:1900:ac8b:7ae5:991f:54fc]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-390cd91093dsm100642f8f.101.2025.02.24.13.04.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 24 Feb 2025 13:04:54 -0800 (PST) Message-ID: Date: Mon, 24 Feb 2025 22:04:53 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 18/20] fs/proc/task_mmu: remove per-page mapcount dependency for "mapmax" (CONFIG_NO_PAGE_MAPCOUNT) To: Zi Yan , linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, Andrew Morton , "Matthew Wilcox (Oracle)" , Tejun Heo , Zefan Li , Johannes Weiner , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Jonathan Corbet , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Muchun Song , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Jann Horn , owner-linux-mm@kvack.org References: <20250224165603.1434404-1-david@redhat.com> <20250224165603.1434404-19-david@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: bMm2dz5eZeneRfdb9gJDvArM9Hd8__T8f_87ijpMPlM_1740431095 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 70EC040003 X-Stat-Signature: s797bd6b9yudjdc3hszghan6o9kkhrfz X-Rspamd-Server: rspam03 X-HE-Tag: 1740431098-737724 X-HE-Meta: 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 nMzOkdkX /rAqObrweGMC4QQxk6dbP/hh2hLXfE1sd/GiK9x6z5eiWx5Pc9thp8+YGgboLWcJKL2Jv/VFPRCsOKqY5AP/oFfAV1OhqUIYUY/liX+O4/A3lfE4F39DlpuQ1Pm4X8ja7TxAfdYzTYYv7k+8Tkw9oCj2npBEAHJsPceYp8nWVqcLJ6jRtTQ+6QWDyrhsPTx7KZXZuirXaUk7eGKqzfxm/OgPxQ3nN6WJOJefXq8UQ4+WFKSjM/CkGrvkE4bC+oa3bUpQsbuevdNAo0EXsJLR+hQKnkSx423cJrgg/gf0GLiZ6XfdcgfvPlU0WgqZFrgz57YtppHzr9CjSYbDPI7b8RzHDwEzTSzn2YHRmRvl92ZsGuWIuANw9ZbWa1cRXYctGMjafFgVBW8OkoWkhDryUmMBH4t5gN0HgPX/7Y6JVs2EgUDBhPf/NsoBtc4ydH7T0UcQHp1s5m6QCt8BeuOd11yxEfw== 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 24.02.25 21:45, Zi Yan wrote: > On Mon Feb 24, 2025 at 11:56 AM EST, David Hildenbrand wrote: >> Let's implement an alternative when per-page mapcounts in large folios are >> no longer maintained -- soon with CONFIG_NO_PAGE_MAPCOUNT. >> >> For calculating "mapmax", we now use the average per-page mapcount in >> a large folio instead of the per-page mapcount. >> >> For hugetlb folios and folios that are not partially mapped into MMs, >> there is no change. >> >> Likely, this change will not matter much in practice, and an alternative >> might be to simple remove this stat with CONFIG_NO_PAGE_MAPCOUNT. >> However, there might be value to it, so let's keep it like that and >> document the behavior. >> >> Signed-off-by: David Hildenbrand >> --- >> Documentation/filesystems/proc.rst | 5 +++++ >> fs/proc/task_mmu.c | 7 ++++++- >> 2 files changed, 11 insertions(+), 1 deletion(-) >> >> diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst >> index 09f0aed5a08ba..1aa190017f796 100644 >> --- a/Documentation/filesystems/proc.rst >> +++ b/Documentation/filesystems/proc.rst >> @@ -686,6 +686,11 @@ Where: >> node locality page counters (N0 == node0, N1 == node1, ...) and the kernel page >> size, in KB, that is backing the mapping up. >> >> +Note that some kernel configurations do not track the precise number of times >> +a page part of a larger allocation (e.g., THP) is mapped. In these >> +configurations, "mapmax" might corresponds to the average number of mappings >> +per page in such a larger allocation instead. >> + >> 1.2 Kernel data >> --------------- >> >> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c >> index 80839bbf9657f..d7ee842367f0f 100644 >> --- a/fs/proc/task_mmu.c >> +++ b/fs/proc/task_mmu.c >> @@ -2862,7 +2862,12 @@ static void gather_stats(struct page *page, struct numa_maps *md, int pte_dirty, >> unsigned long nr_pages) >> { >> struct folio *folio = page_folio(page); >> - int count = folio_precise_page_mapcount(folio, page); >> + int count; >> + >> + if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT)) >> + count = folio_precise_page_mapcount(folio, page); >> + else >> + count = min_t(int, folio_average_page_mapcount(folio), 1); > > s/min/max ? Indeed, thanks! > > Otherwise, count is at most 1. Anyway, if you change > folio_average_page_mapcount() as I indicated in patch 16, this > will become count = folio_average_page_mapcount(folio). No, the average should not be 1 just because a single subpage is mapped. -- Cheers, David / dhildenb