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 23D3FC3ABDD for ; Thu, 15 May 2025 19:20:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2AB5B6B0088; Thu, 15 May 2025 15:20:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2333A6B0092; Thu, 15 May 2025 15:20:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 05CFA6B00A4; Thu, 15 May 2025 15:20:30 -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 D64F86B0088 for ; Thu, 15 May 2025 15:20:30 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id D6036E0754 for ; Thu, 15 May 2025 19:20:31 +0000 (UTC) X-FDA: 83446108662.11.D426E11 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf30.hostedemail.com (Postfix) with ESMTP id 6592E80006 for ; Thu, 15 May 2025 19:20:29 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=RqexHmBV; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf30.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=1747336829; a=rsa-sha256; cv=none; b=DP9e+RYOhJCSTZnP7BwGrZ4/IdwnR9BeIR26YMJ7YS87Q+ct6xX6lv2KfIXJgVTfmgAg/A /1DTCaf+TCekj5dvZcpvpBOJ2O37lsup8LXfYUyOXOaRsM5694yhL2USMNTwyI3KVHnn44 DYyqyUaN1y2x01ablF2YOu+J6m9FHMo= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=RqexHmBV; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf30.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=1747336829; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to: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=iQU5Q6NSs8XSgvdZebhHC1w5xiLFlwEAyk7vktJIOsA=; b=A2a7EnraiiX5/FA4pYDCMusQgEDMvGvfp1KfEzLEmfTBOUQvujabI714iKtGjQ5u7Ngb8B fj4q/hdNdYcaMNSQ8DKjov2PPbg9Y8yxNsY6IXlHlGQkISUOP/aojoG2/We6o6rA79/XX8 +vW7d5/T6pcvu7EWQTFcChw3W+zDZ7g= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747336828; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to: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=iQU5Q6NSs8XSgvdZebhHC1w5xiLFlwEAyk7vktJIOsA=; b=RqexHmBVKRpVqINdgrcLdnlIAjqmYG66x5MKegEDZiwAF062lOgYBUtGboglnNGCRKI9Zi dPcP4m8tL0pTzkPt877fHm6KfAs21ZRiePel+x1312lyQb8BLbNaokHyrhbb9jIgFIBJbX PU6QN05oJ3U0fRGeUvI6ElaeDmRTI2g= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-372-cp3BvgeTOCmuIwHKodyh6A-1; Thu, 15 May 2025 15:20:27 -0400 X-MC-Unique: cp3BvgeTOCmuIwHKodyh6A-1 X-Mimecast-MFC-AGG-ID: cp3BvgeTOCmuIwHKodyh6A_1747336826 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-3a1f7204d72so723071f8f.0 for ; Thu, 15 May 2025 12:20:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747336826; x=1747941626; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=iQU5Q6NSs8XSgvdZebhHC1w5xiLFlwEAyk7vktJIOsA=; b=oZFH0xUIKx4N0WJH9jV/0YqSBDwmTTJ+Rbw0nryU6ZE8EaAkAVxBHa/s5ZcHW5TYQ7 YRe3sxlJ4MHolmRNtKSZsTZERoVuLs8I/++0zY8uKxFtX/XqIXQxJstdU4z/nZSZHoMR kcoaaXu2+DMtU/EAMQwkCzvI0U+Q25HxOIcB5hckK5vCa29lAtYww5yxxjDJSy+P6M6E k1ESyRoXzV4YqoZw0uR7A9QIm9s+Du0aOh3hS/k9sp6YPjByJ1+6XAsQJWhrX1Uprv/K sW1EO7zN/3KQTA+/ER2pmPcF1FCGlSZdrZcqNndGAw49ZOORdQ6j/bKiZSsg5imrhQw7 RhnA== X-Forwarded-Encrypted: i=1; AJvYcCWZDVUAPYh2pTXTNb7zTzYYkI3m+oRTOULeIfjSk/k9v0rWK5ee68l7hd7qGgC/lo42BVC7R9bJ1w==@kvack.org X-Gm-Message-State: AOJu0Yzzr9uFjgJ18w4ZuYQNAI80XLR9LVfx4XQTD8zcbdlkm12sXyQ3 Cz/0vyqhLWpY9fSk/JeLPaIjn3i6YI4C0/4vig92TzDugt2Rk53Pu0hUhjdi/3DxRsfcoxG0/bi MKZx8NjncZFmc+AsKnjESnSFHtSYp73jNc3XBxav91GEYdTrSCArU X-Gm-Gg: ASbGncsqwD7pskhzN+/XxueyjgSr8b3NA3aI0Rm4vYO1moLAc539uS+9ijOFwtkHyB+ YZoSfMyxQDQeobIV3cIipb+GxJydXlguBmPSo1OXMKofF574a1s0gxBxPCEjKcDUKTGPBLJImyX F50l2MQylpaaAlOzqP6f33mj8m9Fw31XkD0Bpu36sLLAM+BV6+2leecF1u8yYfikbIkIlzho2rU OSpsh5TW8wEn7sL4F4Hx1ykh1E/c8PtVIknpMy17mBcQWlGJMlJI4Tf2OIKrL7gmM7C+3ovxEuy JFKsfgZTvxhbHGlPzyR3RCo56snJd0qUXRgAp2YKLpkQpUQkzv99H+B5lrrtf/yZwYe9fnpqjhJ V7cvpxlQQJlbvlKKfxFiW6tHx5FhNeR+rvEWlJ0s= X-Received: by 2002:a5d:558b:0:b0:3a1:f8d1:6340 with SMTP id ffacd0b85a97d-3a35c83aca4mr771940f8f.34.1747336826253; Thu, 15 May 2025 12:20:26 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHIctVlg4RVZvym19LqU8BpCMgLIVCL4/LiXgRWGA4n8fMGVZiMyJI9dwvHkutYErUSeP9g7w== X-Received: by 2002:a5d:558b:0:b0:3a1:f8d1:6340 with SMTP id ffacd0b85a97d-3a35c83aca4mr771926f8f.34.1747336825898; Thu, 15 May 2025 12:20:25 -0700 (PDT) Received: from ?IPV6:2003:d8:2f4a:8900:884a:b3af:e3c9:ec88? (p200300d82f4a8900884ab3afe3c9ec88.dip0.t-ipconnect.de. [2003:d8:2f4a:8900:884a:b3af:e3c9:ec88]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a35ca5a84csm384628f8f.31.2025.05.15.12.20.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 May 2025 12:20:25 -0700 (PDT) Message-ID: <52f12b89-84a1-49ec-a2d2-d710b02218de@redhat.com> Date: Thu, 15 May 2025 21:20:17 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/6] prctl: introduce PR_THP_POLICY_DEFAULT_HUGE for the process To: "Liam R. Howlett" , Lorenzo Stoakes , Usama Arif , Andrew Morton , linux-mm@kvack.org, hannes@cmpxchg.org, shakeel.butt@linux.dev, riel@surriel.com, ziy@nvidia.com, laoar.shao@gmail.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@meta.com References: <20250515133519.2779639-1-usamaarif642@gmail.com> <20250515133519.2779639-2-usamaarif642@gmail.com> <2d30bcce-6f80-468f-945d-b63eff726db5@redhat.com> <360bac52-2cda-41fd-a674-89b113fef918@redhat.com> <7a255984-7c9b-46f1-b73b-f85b5b571a92@lucifer.local> 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: 1pzZ5oQmpC-hWVemvJnpunWQOEIRQtHrkAkUHAFOrYs_1747336826 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-Server: rspam07 X-Rspamd-Queue-Id: 6592E80006 X-Stat-Signature: d7axmu384ywitpeon9gy6kutcy74mum6 X-HE-Tag: 1747336829-694785 X-HE-Meta: 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 TVsPYnpL 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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 15.05.25 20:09, Liam R. Howlett wrote: > * David Hildenbrand [250515 13:30]: >>>> >>> >>> Did we document all this? :) >>> >>> It'd be good to be super explicit about these sorts of 'dependency chains'. >>> >> >> Documentation/admin-guide/mm/transhuge.rst has under "Global THP controls" >> quite some stuff about all that, yes. >> >> The whole document needs an overhaul, to clarify on the whole terminology, >> make it consistent, and better explain how the pagecache behaves etc. On my >> todo list, but I'm afraid it will be a bit of work to get it right / please >> most people. > > Yes, the whole thing is making me grumpy (more than my default state). > The more I think about it, the more I don't like the prctl approach > either... > > I more than dislike flags2... I hate it. > > but no prctl, no cgroups, no bpf.. what is left? A new policy groups > thing? No, not that either, please. > > To state the obvious, none of this is transparent. New to the "transparent" huge page world where not that much is "transparent"!? It's completely in-transparent to most people how it works :D Yeah, that's why I suggested to piggyback on VM_HUGEPAGE/VM_NOHUGEPAGE. Something we already have and that we will probably have for a long time ... :) -- Cheers, David / dhildenb