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 EC05FC369C4 for ; Wed, 16 Apr 2025 16:00:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 254766B0028; Wed, 16 Apr 2025 12:00:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DBD06B0029; Wed, 16 Apr 2025 12:00:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 02D7528012D; Wed, 16 Apr 2025 12:00:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id D5C286B0028 for ; Wed, 16 Apr 2025 12:00:46 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id C6AB3B9BDA for ; Wed, 16 Apr 2025 16:00:46 +0000 (UTC) X-FDA: 83340370092.28.B660ABA Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf12.hostedemail.com (Postfix) with ESMTP id 03D734001E for ; Wed, 16 Apr 2025 16:00:43 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=CRMuJAHd; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf12.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=1744819244; a=rsa-sha256; cv=none; b=g8Cg90grpYC69tl3Y4IFyGMTzsMH7X01XfHoA4Dlvtszvpz+/HopRm2x7UqYnKxCloEpk1 29Rqb5wjrS8DagKr2+2vrBs+1cKXCsZP1Jg7Dr2RSTmde0rzNqFW3JQFfGDFbqQJf2q99h gr8tcnIyb9CSAX+5Me/ua10sAGXQ14w= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=CRMuJAHd; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf12.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=1744819244; 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=+DZwCIfUs9wFLXTTpATle8CKRT23WdS4MzPn69jwFIo=; b=XDiMru4N0wpwLWzcLsS+C3avrPabX/VTH/2JLT93X0XNFJmYNfXvA4O4aimnmFEGp32pp9 XJ78PAdpx5s1qb9BDKDmLt9YZHfVQKGF7iOunAEwKIK3W3qAVy3poEX/y8Ac/n6JCKzxvN bdweAqUXo/k7w68G/APUoePgBu+fqLY= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744819243; 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=+DZwCIfUs9wFLXTTpATle8CKRT23WdS4MzPn69jwFIo=; b=CRMuJAHdEYhJK5WkdCN4rz+4QCr6dC219eWMYMdu0JLcBaQtewWCco2KHV66WAMA26NIOS nmy+qNy485dS2yH5zK85ge5aTsBBfpT30oj9wEpEGl+47sFB73/WHNgrUhktqwhTrMITW+ bYl+uahZ+c3ZaJVEBfTWlanpPgKGBMs= 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-650-x3mXskVWMvCkmKgsJHAGNg-1; Wed, 16 Apr 2025 11:59:16 -0400 X-MC-Unique: x3mXskVWMvCkmKgsJHAGNg-1 X-Mimecast-MFC-AGG-ID: x3mXskVWMvCkmKgsJHAGNg_1744819155 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-39c2da64df9so4041888f8f.0 for ; Wed, 16 Apr 2025 08:59:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744819155; x=1745423955; 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=+DZwCIfUs9wFLXTTpATle8CKRT23WdS4MzPn69jwFIo=; b=SGgKNH0k2hYir8HZHh1dey//Lk33nUQH3jYS8P3Labf8mPyhDRvTZ7Yg0VOGVTva0N UAsiBp8SfVWSo1KbXzqWBVE3r7kW5VLxJBeopHZ6N1yxdizZaYqudn66zpKAT0IOfZ72 DFZuDWUUMLKRQ/BI9yfwscUM5+bIowXBFJYZxk6f0WgKaVV95TvXwTCj3OuaIj5RJ1w2 +j7OM8Ka/lsLyeRfo/HsaEo5Rs16nCjRZwmd3sFJIGMTiqHaEXEMxaE8yFL2i4Tk89eC yWfYv3P1JFZHKASjBJFm0r7I9gQXZ1aRVw6Cr4UA3N9TBPAcmpiEY2OZwK/U1bIIGVur H1dw== X-Forwarded-Encrypted: i=1; AJvYcCWC+5HOKpFPHxvGI27TATy21SHdyuOfNGSGu//qGPvhMYHeB/RM085yNqD1u8Mt5bf21Ov47NTc9g==@kvack.org X-Gm-Message-State: AOJu0YyWX16NuNd/yaMmbjIGn0rWrJe+xrPBu8bcmoEpeeRqVG2c1mlV Hzv7cw4IbaxKCl+jb0HkHpkalK7ucgVezuRYkk7XnQbzWsZZcruMzLq7X51X8wYYDRv89+YnzIi uCizrqkg5GoWwCQ2Bq8ax89XEzzEfJnypL5qRhpMW66oZBVYi X-Gm-Gg: ASbGnctVUgXXGfMgcLTHO0aHiNVnRRmboj+iy03GLiWMofU3NmYqkINpcAd3k/+U7aG GnnUNiIIfTJ/RNmQmo6iAPnM5nIfrqqjj8P/GvwBjG0FRcVd1KsCXKPSyPtmg4QWbwdyRniYoyj 44wO5AkaWJjQByQ2M+jmd3jjxyJTkd9jLG9qGId5eYT1Un3if4NHFcvIko8B09ZOglEqq4LFBjA eL/hS4Df+uyHeQUa4KqJW50L4bnodEt0zsgPkHL039BRfeWQIEqR7kSh63mAEdfNet7D14TaUXn k5B269fdMC24qWRDC3T8vCz9U34dvsrleEgyXRndnRnrLy5xnvsfL3TMdS3i4ELIqSVe1f11ZD9 PRSfyFJac4xy+mjxsd4xeaBpbxtaeKX3Da9CJ2A== X-Received: by 2002:a5d:588b:0:b0:39e:db6a:4744 with SMTP id ffacd0b85a97d-39ee5b36643mr2029700f8f.32.1744819154759; Wed, 16 Apr 2025 08:59:14 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFmnJhwRRclmWTkmZX1vwkTJYXdNujxbArJZM45by1egZJzXDqpsM2ags0teKMiQHx7D+Y94w== X-Received: by 2002:a5d:588b:0:b0:39e:db6a:4744 with SMTP id ffacd0b85a97d-39ee5b36643mr2029674f8f.32.1744819154279; Wed, 16 Apr 2025 08:59:14 -0700 (PDT) Received: from ?IPV6:2003:d8:2f02:2900:f54f:bad7:c5f4:9404? (p200300d82f022900f54fbad7c5f49404.dip0.t-ipconnect.de. [2003:d8:2f02:2900:f54f:bad7:c5f4:9404]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4405b4c826esm24921225e9.7.2025.04.16.08.59.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 16 Apr 2025 08:59:13 -0700 (PDT) Message-ID: <239cfe47-9826-402b-8008-de707faa160e@redhat.com> Date: Wed, 16 Apr 2025 17:59:12 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH] mm: don't promote exclusive file folios of dying processes To: Johannes Weiner Cc: Barry Song <21cnbao@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Barry Song , Baolin Wang , Matthew Wilcox , Oscar Salvador , Ryan Roberts , Zi Yan References: <20250412085852.48524-1-21cnbao@gmail.com> <34c54df6-9a7c-475d-9b91-0f8acb118231@redhat.com> <6259cc1d-93a8-4293-9009-a6119166f023@redhat.com> <20250416141531.GD741145@cmpxchg.org> 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: <20250416141531.GD741145@cmpxchg.org> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 3CWQcFzbyFinzA9UhAtunt8maiqRqhwZSdzwomYgOcA_1744819155 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: 03D734001E X-Stat-Signature: icaryjpb7ij86ykms7ewcgx8xz6f7nx8 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1744819243-171816 X-HE-Meta: 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 6P6Ln+XA BJ9AwqCOIxqil4Kpc6RiRV7MA3hhtiEUk7F/RGFvcXhA75f7B7kV9IjGxA6ag2MW4WLlEEQ3rc+seIvwE7H5rF6X7PjFiRb3gV7q3kz6Wk4gXtwc1pDNiXEPrqIU2kfG96rMXuOONXAMEuSUWEQD+Aw4C3WcUf2T66hSOdOEqitqHEqsmChh3to9MFSXnzeoaGuxqpvvnM4w89s9R8dTgIx9NntTDXis6glftzp3sPZX81Sp/OFSDvcdt1O+15zWhHuagsBxpV1oRsVy8zwtmfFBBYu4Vy+KKz6Z0Wl2i7o0SYMbJfK3gjWH906iLUY0zbvSjcQ+6dHFgEY3qJ0h1CDoMqmWlsXlAEBljuC8OxCcYfP1EZe2neg+OfbJMyQ335D+HwWgL8jX+lVuhfC0gY+hgOaSp1Mj3cJIVvnAdjXACFAC74ZnLwaU1UL0ZQxHZusPMxcTTzRX7UbFXYvu6muJ4/SSYvjdEXD67 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 16.04.25 16:15, Johannes Weiner wrote: > On Wed, Apr 16, 2025 at 11:40:31AM +0200, David Hildenbrand wrote: >> On 16.04.25 11:38, Barry Song wrote: >>> On Wed, Apr 16, 2025 at 5:32 PM David Hildenbrand wrote: >>>> >>>> On 16.04.25 11:24, Barry Song wrote: >>>>> On Wed, Apr 16, 2025 at 4:32 PM David Hildenbrand wrote: >>>>>> >>>>>> On 12.04.25 10:58, Barry Song wrote: >>>>>>> From: Barry Song >>>>>>> >>>>>>> Promoting exclusive file folios of a dying process is unnecessary and >>>>>>> harmful. For example, while Firefox is killed and LibreOffice is >>>>>>> launched, activating Firefox's young file-backed folios makes it >>>>>>> harder to reclaim memory that LibreOffice doesn't use at all. >>>>>> >>>>>> Do we know when it is reasonable to promote any folios of a dying process? >>>>>> >>>>> >>>>> I don't know. It seems not reasonable at all. if one service crashes due to >>>>> SW bug, systemd will restart it immediately. this might be the case promoting >>>>> folios might be good. but it is really a bug of the service, not a normal case. >>>>> >>>>>> Assume you restart Firefox, would it really matter to promote them when >>>>>> unmapping? New Firefox would fault-in / touch the ones it really needs >>>>>> immediately afterwards? >>>>> >>>>> Usually users kill firefox to start other applications (users intend >>>>> to free memory >>>>> for new applications). For Android, an app might be killed because it has been >>>>> staying in the background inactively for a while. >>>> >>>>> On the other hand, even if users restart firefox immediately, their folios are >>>>> probably still in LRU to hit. >>>> >>>> Right, that's what I'm thinking. >>>> >>>> So I wonder if we could just say "the whole process is going down; even >>>> if we had some recency information, that could only affect some other >>>> process, where we would have to guess if it really matters". >>>> >>>> If the data is important, one would assume that another process would >>>> soon access it either way, and as you say, likely it will still be on >>>> the LRU to hit. >>> >>> I'll include this additional information in the v2 version of the patch since >>> you think it would be helpful. >>> >>> Regarding the exclusive flag - I'm wondering whether we actually need to >>> distinguish between exclusive and shared folios in this case. The current >>> patch uses the exclusive flag mainly to reduce controversy, but even for >>> shared folios: does the recency from a dying process matter? The >>> recency information only reflects the dying process's usage pattern, which >>> will soon be irrelevant. >> >> Exactly my thoughts. So if we can simplify -- ignore it completely -- >> that would certainly be nice. > > This doesn't sound right to me. > > Remembering the accesses of an exiting task is very much the point of > this. Consider executables and shared libraries repeatedly referenced > by short-lived jobs, like shell scripts, compiles etc. For these always-mmaped / never read/write files I tend to agree. But, is it really a good indication whether a folio is exclusive to this process or not? I mean, if a bash scripts executes the same executable repeatedly, but never multiple copies at the same time, we would also not tracking the access with this patch. Similarly with an app that mmaps() a large data set (DB, VM, ML, ..) exclusively. Re-starting the app would not track recency with this patch. But I guess there is no right or wrong ... -- Cheers, David / dhildenb