From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E003C289356 for ; Thu, 17 Jul 2025 09:25:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752744329; cv=none; b=Fq2f/RnJcbo1Xcyg24cyFJODSiyzGPdP6Og1iOvceYxL/1izeGZiuc6Kf1fch+dVEMOOmNgzsJskNJtGvd4FLr9SCs8psmV72gKUYLfVpHhvAhV0hYEfhzklB/2BB8bAjOk9rGvbav/oWmhJeCn7Pk+LoFpcwGP0Sge5upUnkOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752744329; c=relaxed/simple; bh=ihTiDkt+TvI2NETJi4pl7z1XW8Im22JbrlopYk5azTM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sqFEllx7kvXXIev7pMFLSWxaR+FN/szlBcQL4V/1/8Jvr3uh0J6TtkI3lSX80+TTODg+N4bseJvUr8opJ7oRj7/jZA0mKX63e+3p0ove8fNcc2vA6RMOdFOeZkQp6UBsyJbbPMEazXWrjKLF7iL9r2J0RrzEfCJMz++LIFSUmhY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=B1FgyYsY; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="B1FgyYsY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752744325; 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=E9ev3yrD+ML0m+nGXZuixbaX7IjF/q9l8W1aFJb/xy0=; b=B1FgyYsYgN4iPzFlW3sj8FD/l8yPiZQ0f5kZO/jVFTkJOR1QhA073BcH3yl62abW6BobVX k0m+BB3P5DPJgk/qPSSNCOA/NY3iTCzipiw6Ss+vNeSAMDu+uu8KqvB/eoY6h/fAasykiP LkGvz/tgzhQi9J1jIdn0NU56vJXoCW4= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-504-S0zgBR1OOOOY-jPcL9E5Fw-1; Thu, 17 Jul 2025 05:25:23 -0400 X-MC-Unique: S0zgBR1OOOOY-jPcL9E5Fw-1 X-Mimecast-MFC-AGG-ID: S0zgBR1OOOOY-jPcL9E5Fw_1752744323 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-45597cc95d5so3696155e9.1 for ; Thu, 17 Jul 2025 02:25:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752744322; x=1753349122; 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=E9ev3yrD+ML0m+nGXZuixbaX7IjF/q9l8W1aFJb/xy0=; b=VFlR0k+j2ot/h8XGksnHXs6qCj+eIGBCQb3qzkhJVWcDw0dWqYa8XvuQqM8wEBhKwA d62tZhV0ad3jWuKULT1vmoBrKaL+h5o8aghvqwMmndruU5zariQ6hYHlSBVwYKVkSV0P gWtDBS5zQfcaJ9hRqwDzxbr7oqu6H3AGDr0MtAQTMgIcPm/MTtuNnqKUhNsTErBl9uTP 53xU/LfZXB5YCJBO9H3r+GIBg530tnMOSZ/Nk9DiY4ldOiAfXL7b00FG/74DPpeKdSTD URTjJb6eJ0Tyx7aHPEQLeW7US1iKwUTRKFdT1sIfoSgCDh5G20MpmvnemBQufwPMmXwI fTKw== X-Forwarded-Encrypted: i=1; AJvYcCVGVcvJSj1JLGROFdh1aQ6LZHWLmqUZaZNc4VCNDiAO4qioQ70vNRpMhTtNoFakrifc8yb5ow7Lbwr6r1g=@vger.kernel.org X-Gm-Message-State: AOJu0YwaNtutWW9FzGGiV+BHroa/BuCSsxb9jBZz5sPvQoMyY9NIBnAl dfonqXpeisFEn+V40Yx8oQqYAn9bLOYIKNi42pm8FQYE8ZPwbWOPYBu2sf8l7gLWLarNiwzHoHF zsAghOHVM2iXnPsZbymfOhnogo4SbYmSG2P7B3RgNl/liFtDPda3GCQIqYiCqTxHHHg== X-Gm-Gg: ASbGnct6iL0/9UmgrkoEJlS2D0+CnvNFXM0smy3ioFDVLHpT8w1s5/HamWm2AQ6qOrR JYMAWnVVf05NmSd2fqK5ikhDbXobw5NlfxW/2tzA8ZYnszPiiNO91Ymeq277uWwXrjlz9WXGyW9 iO0sdpKzYb/WkYbCEfbSDLZPvbi6bSchQZ9+oE0TI7w9eApKWIxm+CioKlHByJqyx0JHnDJ8EMW fJd4wgBGEXItZw0toK3uIDsmvoqa9mela5mavyt6iphMJ3UYtQcuZPsGoGNTaT4Ve/JUYyglERd 7+1u7s7kWWWY4OMlnD+jgzNJUStnRaBFehTp8qb1xVMxmRi5LdFZtaK+BLIHeNE4/XA4qqncPdf OfBD7AAGBMbIir+7QsNenQ3Hm6M5S6caEK+YLpSban7HHYr9nv8DzuIP2SosUW7zy X-Received: by 2002:a05:600c:3b19:b0:456:19be:5e8 with SMTP id 5b1f17b1804b1-4562e38aafcmr51128155e9.20.1752744322453; Thu, 17 Jul 2025 02:25:22 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFRSNBai7Gozzz1k2MwVuqNIicrKF5gocm+tYkQxzjnOpt9HcWWJO7+Azmck5VG0LoPpzvd2Q== X-Received: by 2002:a05:600c:3b19:b0:456:19be:5e8 with SMTP id 5b1f17b1804b1-4562e38aafcmr51127815e9.20.1752744321966; Thu, 17 Jul 2025 02:25:21 -0700 (PDT) Received: from ?IPV6:2003:d8:2f1f:3600:dc8:26ee:9aa9:fdc7? (p200300d82f1f36000dc826ee9aa9fdc7.dip0.t-ipconnect.de. [2003:d8:2f1f:3600:dc8:26ee:9aa9:fdc7]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4562eb63551sm44492755e9.24.2025.07.17.02.25.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Jul 2025 02:25:21 -0700 (PDT) Message-ID: Date: Thu, 17 Jul 2025 11:25:20 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm: fault in complete folios instead of individual pages for tmpfs To: Lorenzo Stoakes Cc: Baolin Wang , Hugh Dickins , Andrew Morton , Matthew Wilcox , ziy@nvidia.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <440940e78aeb7430c5cc8b6d2088ae98265b9809.1751599072.git.baolin.wang@linux.alibaba.com> <20250704151858.73d35a24b4c2f53bdb0c1b85@linux-foundation.org> <4c055849-d7dd-4b9f-9666-fcb0bccf8681@linux.alibaba.com> <007c4a94-c94a-418e-9907-7510422f8ca4@lucifer.local> <23f1c3ab-16ca-41db-b008-22448d9e08f2@linux.alibaba.com> <3bf50873-4d1b-a7c7-112e-3a17ac16077f@google.com> <2513a63d-b11a-48fc-922a-288785817df4@redhat.com> <048c8d4d-5e5b-472f-850b-6392b8f4d2a5@lucifer.local> From: David Hildenbrand Content-Language: en-US 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/g1oFAmgsLPQFCRvGjuMACgkQTd4Q 9wD/g1o0bxAAqYC7gTyGj5rZwvy1VesF6YoQncH0yI79lvXUYOX+Nngko4v4dTlOQvrd/vhb 02e9FtpA1CxgwdgIPFKIuXvdSyXAp0xXuIuRPQYbgNriQFkaBlHe9mSf8O09J3SCVa/5ezKM OLW/OONSV/Fr2VI1wxAYj3/Rb+U6rpzqIQ3Uh/5Rjmla6pTl7Z9/o1zKlVOX1SxVGSrlXhqt kwdbjdj/csSzoAbUF/duDuhyEl11/xStm/lBMzVuf3ZhV5SSgLAflLBo4l6mR5RolpPv5wad GpYS/hm7HsmEA0PBAPNb5DvZQ7vNaX23FlgylSXyv72UVsObHsu6pT4sfoxvJ5nJxvzGi69U s1uryvlAfS6E+D5ULrV35taTwSpcBAh0/RqRbV0mTc57vvAoXofBDcs3Z30IReFS34QSpjvl Hxbe7itHGuuhEVM1qmq2U72ezOQ7MzADbwCtn+yGeISQqeFn9QMAZVAkXsc9Wp0SW/WQKb76 FkSRalBZcc2vXM0VqhFVzTb6iNqYXqVKyuPKwhBunhTt6XnIfhpRgqveCPNIasSX05VQR6/a OBHZX3seTikp7A1z9iZIsdtJxB88dGkpeMj6qJ5RLzUsPUVPodEcz1B5aTEbYK6428H8MeLq NFPwmknOlDzQNC6RND8Ez7YEhzqvw7263MojcmmPcLelYbfOwU0EVcufkQEQAOfX3n0g0fZz 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+DWgUCaCwtJQUJG8aPFAAKCRBN3hD3AP+DWlDnD/4k2TW+HyOOOePVm23F5HOhNNd7nNv3 Vq2cLcW1DteHUdxMO0X+zqrKDHI5hgnE/E2QH9jyV8mB8l/ndElobciaJcbl1cM43vVzPIWn 01vW62oxUNtEvzLLxGLPTrnMxWdZgxr7ACCWKUnMGE2E8eca0cT2pnIJoQRz242xqe/nYxBB /BAK+dsxHIfcQzl88G83oaO7vb7s/cWMYRKOg+WIgp0MJ8DO2IU5JmUtyJB+V3YzzM4cMic3 bNn8nHjTWw/9+QQ5vg3TXHZ5XMu9mtfw2La3bHJ6AybL0DvEkdGxk6YHqJVEukciLMWDWqQQ RtbBhqcprgUxipNvdn9KwNpGciM+hNtM9kf9gt0fjv79l/FiSw6KbCPX9b636GzgNy0Ev2UV m00EtcpRXXMlEpbP4V947ufWVK2Mz7RFUfU4+ETDd1scMQDHzrXItryHLZWhopPI4Z+ps0rB CQHfSpl+wG4XbJJu1D8/Ww3FsO42TMFrNr2/cmqwuUZ0a0uxrpkNYrsGjkEu7a+9MheyTzcm vyU2knz5/stkTN2LKz5REqOe24oRnypjpAfaoxRYXs+F8wml519InWlwCra49IUSxD1hXPxO WBe5lqcozu9LpNDH/brVSzHCSb7vjNGvvSVESDuoiHK8gNlf0v+epy5WYd7CGAgODPvDShGN g3eXuA== Organization: Red Hat In-Reply-To: <048c8d4d-5e5b-472f-850b-6392b8f4d2a5@lucifer.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 17.07.25 11:20, Lorenzo Stoakes wrote: > On Thu, Jul 17, 2025 at 10:22:47AM +0200, David Hildenbrand wrote: >> I recall [1]. But that would, of course, only affect the RSS of a program >> and not the actual memory consumption (the large folio resides in memory >> ...). >> >> The comments in the code spells that out: "inflating the RSS of the >> process." > > RSS is a pretty sucky measure though, as covered in depth by Vlastimil in > his KR 2024 talk [2]. So maybe we don't need to worry _so_ much about this > :) Well, I pointed an an actual issue where people *did* worry about ;) I also think that it's probably fine, but some apps/environments apparently don't enjoy suddenly seeing spikes in RSS. Maybe these are so specific that only distributions like in the report have to worry about that (good luck once the toggles are gone, lol). -- Cheers, David / dhildenb