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 DE090C25B5C for ; Mon, 6 May 2024 19:18:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6AD546B009C; Mon, 6 May 2024 15:18:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 65DA86B009D; Mon, 6 May 2024 15:18:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D6336B009E; Mon, 6 May 2024 15:18:25 -0400 (EDT) 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 30FC76B009C for ; Mon, 6 May 2024 15:18:25 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id DE8C5A0737 for ; Mon, 6 May 2024 19:18:24 +0000 (UTC) X-FDA: 82088932128.06.A6F6E45 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf01.hostedemail.com (Postfix) with ESMTP id 9418640010 for ; Mon, 6 May 2024 19:18:22 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=fyolRWvK; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf01.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=1715023102; 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=L0itG5n8en1QP9QC0UQ1zw+U4P2Qru8sUoqUPu1ADzA=; b=TbnevBej5zhgojvz0B9dYZAnbX3MTb7WbF+Pu8s6ESr8AuPGMLkjje6XKlsxoUAmGixelD FT/8kdgwUbFUUom1uPObAajF3lwh8t4KiGxTGqqMBAWvRPYvr6CNkaxbd2PYwA7qBca9DU IvfMzJ3XZSm3oEOONaX/Vh6gWbQftEY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1715023102; a=rsa-sha256; cv=none; b=vYya50ldKvCgHlMOxAqmjenl7kqTIg1tOL0xEEtGvCrGFxc17kG7xVuHjkJEX+V1wjl8+I T/+UsLSf2O0FyCTtGDy6nJM1Yy7tIClXbnzKy22B0FxZfKPlXMkIymH5VFpqvkOjT3ZzaF CMn651oxipdlQG1FcFu8W66mcojmj2w= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=fyolRWvK; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1715023102; 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=L0itG5n8en1QP9QC0UQ1zw+U4P2Qru8sUoqUPu1ADzA=; b=fyolRWvKIJghS2oitYMNg/bj+dSiZcyo0vxCMuerbX7wP5jc/DtCwWcgAoCFu8Bo3Z1bD2 jt5dt9hmxQBIs/9DKUfeKH1EcqB3DE4kXVscHUrOmfZeAvwJbMAKD+TjDmVbiE15Vtm4RR GLREei9U/NXuCSLZr3WV7d28PFVV6Hg= Received: from mail-lj1-f200.google.com (mail-lj1-f200.google.com [209.85.208.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-586-MsJ_AzwqMPKJ3Bgw9hQ_zA-1; Mon, 06 May 2024 15:18:20 -0400 X-MC-Unique: MsJ_AzwqMPKJ3Bgw9hQ_zA-1 Received: by mail-lj1-f200.google.com with SMTP id 38308e7fff4ca-2e1c0468503so14608561fa.1 for ; Mon, 06 May 2024 12:18:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715023099; x=1715627899; 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=L0itG5n8en1QP9QC0UQ1zw+U4P2Qru8sUoqUPu1ADzA=; b=iBirE3L3f1dO6lH80oMqPz25/TtwtVeax/tmORINW4IUBftbNhmtltgthiEgN7t+pq sxpciHXInGrALN8cqpe1dT9mOz8oJ8tDbyJKq8mEU3WfHYZvD5KNwI81Q/K85VtRaoZY 6CBkYKgqsy9h/AOhuzKcqfQXIuazj1UhnfVPRITvBdBmjOiwKJXXs68TaAIIhEYFyEsZ h/nkAHsJ5/95KnG8FLKYQ3yBdzNmyXIjpoF3lBRiRktNAEaV/3xHoAMl/VbF9yHDaxQx 7S2Dq3+VQdCuq/Int/vB8qj28h1eUTbO4meAQMpaT2Ij+uCwRYERYA6yFuIzHIoFPBFf Kpeg== X-Forwarded-Encrypted: i=1; AJvYcCU8ExV4yIR9cNjYJ3ijn4FNXBZllErNenBXodRI9FzWMepnpC6h6MGPQaglyl9J7l6yBuNWZ49pC9YQ41w74ndc8YE= X-Gm-Message-State: AOJu0Yx34Qp4B2GkW47+L7CPLL0NaWvPVeOFBiTpwPe0ulgLrNtWmxkT DtJVAXT2EvehiT+iEEQ3zj5brETELUKC0m1xN06BX1ii+aUoffUe9Dbg43AXuyKkw27lNirDexN gHP/1XCmaIlBxHDft1tzFvtO7dpsTniOpwOtYx41PYVozFG5n X-Received: by 2002:a2e:be03:0:b0:2e0:c6ec:bcc1 with SMTP id z3-20020a2ebe03000000b002e0c6ecbcc1mr7571405ljq.45.1715023098953; Mon, 06 May 2024 12:18:18 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFo2gUPC1i/xcQESDY8BN5lT9tpYqSixSUd/jFbyXrwtj5agefi6tPI4djtTPG8IslTx/Frjg== X-Received: by 2002:a2e:be03:0:b0:2e0:c6ec:bcc1 with SMTP id z3-20020a2ebe03000000b002e0c6ecbcc1mr7571377ljq.45.1715023098303; Mon, 06 May 2024 12:18:18 -0700 (PDT) Received: from ?IPV6:2003:cb:c74b:bf00:182c:d606:87cf:6fea? (p200300cbc74bbf00182cd60687cf6fea.dip0.t-ipconnect.de. [2003:cb:c74b:bf00:182c:d606:87cf:6fea]) by smtp.gmail.com with ESMTPSA id f12-20020a05600c154c00b0041be609b1c7sm20714480wmg.47.2024.05.06.12.18.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 06 May 2024 12:18:17 -0700 (PDT) Message-ID: Date: Mon, 6 May 2024 21:18:16 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED To: Yosry Ahmed Cc: Andrew Morton , Shakeel Butt , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+9319a4268a640e26b72b@syzkaller.appspotmail.com References: <20240506170024.202111-1-yosryahmed@google.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-Rspamd-Queue-Id: 9418640010 X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: i4ej3gicgc9xpp1ur3nqfm4etuaq1mp3 X-HE-Tag: 1715023102-220364 X-HE-Meta: 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 eNusquby 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000066, 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 06.05.24 20:52, Yosry Ahmed wrote: > On Mon, May 6, 2024 at 11:35 AM David Hildenbrand wrote: >> >> On 06.05.24 19:00, Yosry Ahmed wrote: >>> Do not use __lruvec_stat_mod_folio() when updating NR_FILE_PMDMAPPED and >>> NR_SHMEM_PMDMAPPED as these stats are not maintained per-memcg. Use >>> __mod_node_page_state() instead, which updates the global per-node stats >>> only. >> >> What's the effect of this? IIUC, it's been that way forever, no? > > Yes, but it has been the case that all the NR_VM_EVENT_ITEMS stats > were maintained per-memcg, although some of those fields are not > exposed anywhere. > > Shakeel recently added commit14e0f6c957e39 ("memcg: reduce memory for > the lruvec and memcg stats"), which changed this such that we only > maintain the stats we actually expose per-memcg (via a translation > table). Valuable information we should add to the patch description :) > > He also added commit 514462bbe927b ("memcg: warn for unexpected events > and stats"), which warns if we try to update a stat per-memcg that we > do not maintain per-memcg (i.e. the warning firing here). The goal is > to make sure the translation table has all the stats it needs to have. > > Both of these commits were just merged today into mm-stable, hence the > need for the fix now. It is the warning working as intended. No Fixes > or CC stable are needed, but if necessary I would think: WARN* should usually be "Fixes:"d, because WARN* expresses a condition that shouldn't be happening. Documentation/process/coding-style.rst contains details. > > Fixes: 514462bbe927b ("memcg: warn for unexpected events and stats") > > , because without the warning, the stat update will just be ignored. > So if anything the warning should have been added *after* this was > fixed up. Ideally, yes. But if it's in mm-stable, we usually can no longer reshuffle patches (commit IDs stable). -- Cheers, David / dhildenb