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 5BC34C7EE39 for ; Mon, 30 Jun 2025 09:08:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DA5C96B009A; Mon, 30 Jun 2025 05:08:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D7DBC6B009E; Mon, 30 Jun 2025 05:08:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C930D6B009F; Mon, 30 Jun 2025 05:08:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id B89B76B009A for ; Mon, 30 Jun 2025 05:08:43 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6C9A0160414 for ; Mon, 30 Jun 2025 09:08:43 +0000 (UTC) X-FDA: 83611491726.19.A1FCF0A Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf06.hostedemail.com (Postfix) with ESMTP id D5DF4180004 for ; Mon, 30 Jun 2025 09:08:40 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=cfQi8G8P; spf=pass (imf06.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751274521; 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=64xC4zQ8+9vm0l1IYRTEX7hKYTJUCSlbYR5cwQZC1I0=; b=pgGLdmu93bZUNFGuwJ8VNWXy558xPAfR8ivVh5TdhmWV5E0/jcGssZ7uzx/7os7+rtTOLx Y3erB6A+aqoq/lH624EuCV/JOX0pNISUPzPGzKes8qYz74/6l8nQLUmb875891jntFVCwL +P64EbXXLLFTfpld1D7F+tcp/vOp4eY= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=cfQi8G8P; spf=pass (imf06.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1751274521; a=rsa-sha256; cv=none; b=bCfPjgXgYeZl/UwAfmurF93P/6trDBrnq3VdzhPvjdvXXrrJsUgNwL1GsyLSHfEMnolLUd WUpnS84hOohFEqUXlpwMSI7n7X49mCRZy5M+HsZX9hq1bpi9/hO1Z7bBc2vXbRrEwsvRq5 X+BJ+epmSuSBh6oYqDXf28DpocAGQnU= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1751274520; 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=64xC4zQ8+9vm0l1IYRTEX7hKYTJUCSlbYR5cwQZC1I0=; b=cfQi8G8PFrOg8Hpri64bjuOTT9zt5e6vhttx/jUs2mhg9f8mh4nZwvNcMFkUCdGgZdOyr4 Uq7NXBiUtF+lQHyHThihkZ9H8WjqHNIEAclZgHqtsLD3BVwO9/FMe+fz8KQRgTTDdF8KZY eN+Ao3TW3QiGw3MB9hcbWSK4euvySAc= 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-633-OZk43S3SN8aib0qeWupZ8g-1; Mon, 30 Jun 2025 05:08:38 -0400 X-MC-Unique: OZk43S3SN8aib0qeWupZ8g-1 X-Mimecast-MFC-AGG-ID: OZk43S3SN8aib0qeWupZ8g_1751274517 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-3a4f6ba526eso1147948f8f.1 for ; Mon, 30 Jun 2025 02:08:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751274517; x=1751879317; 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=64xC4zQ8+9vm0l1IYRTEX7hKYTJUCSlbYR5cwQZC1I0=; b=hTmf6n6DW4uv593E3gcez2ZFcBvROYoeAkm7kvG1snzyz0PhKjuNPXwe3pHoGpBlzH 6X72h+i8B0y8+8MXPgICknGaC+0PDgoKUFt+gWNJ0VzC55/dosySvA/FV9h+2J3h2ZnH JMXvEL0SfmjlZ1NBB3xepunFR0OGNn42MurDhIMU3x7IvqfcKIN8ZeukaVm1Y+ktk1SG LQbqkk2V1YS0BtCr3fqikuUilz0lMAIAQE0ZKBQsun2QNe4D0Ogglq9dN3MLt1mDxlSy IZOglKdgigLmIk7So0Ug69gjcp1b91DOifQ16whvRx8islZX0HjpxBQTXu0MPs3ATNu/ aP2w== X-Gm-Message-State: AOJu0YyG9K80CwUCT+G4sMFPePO9bjm3ALDQScDWgs5qONUi0baq8bEK 4ZOyy6oqOSyzVx7RaXwxxpFZyHDYBysoTzrBDoGqkcaQtIrrm3z9Enp36/EH8mb6ruXidW/JAMr 44XzMi9jlE9iVzzXIVVMf38MnlZzuc292CXuUhzrnX2b6UlZj95Cu X-Gm-Gg: ASbGnctRBfQCZGd5QiVV/hchXm3v7/7k9wWvdlpRfrs1n1zuS619QNhWqQvl42io0Yl eBbNPMnkdahDL5s9Bwk7j11mxhfhr1aUT3JXYPV5bEK6rtteufXNnVN5TkNs80VVF2w0q1nKhI7 /3v4dMzXn9LOuyGvpWv5Lz7DExLjOUvf/1LeIWy147/2KafGPTkADh6eeY5IH5orz7XhQhbUMrf ghpPOfCO5Ip5JayYOCWPycQzWWJA62WoGA1EnqzhMLFRKXUUcmrxPmOtBmPZjKvHTcRbH7HCQBi MDhQGE/VrmYnxxvZAPBd5U9IoqV44yr+KE+gM93oYpU/dtHiLVV+8RMmqn/M4GIMlKW7Ro/ZDQ9 1hfeX8+p2Y8y3PeqZSfRlCJmU4UE5ZwgAaV0fdnfZIIfYDIVZ1w== X-Received: by 2002:a05:6000:2807:b0:3a4:f892:de7f with SMTP id ffacd0b85a97d-3a8fee65129mr7468785f8f.36.1751274517053; Mon, 30 Jun 2025 02:08:37 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHJLXMZpwmNlVuaEbYCO/poMsOERDXHknjrrriyl3NfUpRhPKQc/NITgoCmhjRuusQcOSt1HA== X-Received: by 2002:a05:6000:2807:b0:3a4:f892:de7f with SMTP id ffacd0b85a97d-3a8fee65129mr7468743f8f.36.1751274516534; Mon, 30 Jun 2025 02:08:36 -0700 (PDT) Received: from ?IPV6:2003:d8:2f40:b300:53f7:d260:aff4:7256? (p200300d82f40b30053f7d260aff47256.dip0.t-ipconnect.de. [2003:d8:2f40:b300:53f7:d260:aff4:7256]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a88c80b5aesm9718838f8f.44.2025.06.30.02.08.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 30 Jun 2025 02:08:35 -0700 (PDT) Message-ID: Date: Mon, 30 Jun 2025 11:08:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/4] mm: convert FPB_IGNORE_* into FPB_HONOR_* To: Ryan Roberts , Dev Jain , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Andrew Morton , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Jann Horn , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Zi Yan , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Pedro Falcato , Rik van Riel , Harry Yoo References: <20250627115510.3273675-1-david@redhat.com> <20250627115510.3273675-2-david@redhat.com> <5c3428c6-25be-4a94-811a-6bb6718f6c58@arm.com> <5375208d-2c11-4579-a303-e8416ab07159@arm.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: rs1bnI4AgsVr3MlDHnfhL4sFgkyCkA1OB4TVM9r_6Vo_1751274517 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: rspam06 X-Rspamd-Queue-Id: D5DF4180004 X-Stat-Signature: tr95hr6chznidxkywsned71aq1ueqiuw X-HE-Tag: 1751274520-337398 X-HE-Meta: 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 qjGXUhD4 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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 30.06.25 11:04, Ryan Roberts wrote: > On 30/06/2025 04:34, Dev Jain wrote: >> >> On 29/06/25 2:30 am, David Hildenbrand wrote: >>> On 28.06.25 05:37, Dev Jain wrote: >>>> >>>> On 27/06/25 5:25 pm, David Hildenbrand wrote: >>>>> Honoring these PTE bits is the exception, so let's invert the meaning. >>>>> >>>>> With this change, most callers don't have to pass any flags. >>>>> >>>>> No functional change intended. >>>> >>>> FWIW I had proposed this kind of change earlier to Ryan (CCed) and >>>> he pointed out: "Doesn't that argument apply in reverse if you want >>>> to ignore something new in future? >>>> >>>> By default we are comparing all the bits in the pte when determining the batch. >>>> The flags request to ignore certain bits. >>> >>> That statement is not true: as default we ignore the write and young bit. And >>> we don't have flags for that ;) >>> >>> Now we also ignore the dirty and soft-dity bit as default, unless told not to >>> do that by one very specific caller. >>> >>>> If we want to ignore extra bits in >>>> future, we add new flags and the existing callers don't need to be updated. >>> >>> What stops you from using FPB_IGNORE_* for something else in the future? >>> >>> As a side note, there are not that many relevant PTE bits to worry about in >>> the near future ;) >>> >>> I mean, uffd-wp, sure, ... and before we add a FPB_HONOR_UFFD_WP to all users >>> to be safe (and changing the default to ignore), you could add a >>> FPB_IGNORE_UFFD_WP first, to then check who really can tolerate just ignoring >>> it (most of them, I assume). >> I agree. > > Meh. Personally I think if you start mixing HONOR and IGNORE flags, it becomes > very confusing to work out what is being checked for and what is not. I stand by > my original view. But yeah, writable and young confuse it a bit... How about > generalizing by explicitly requiring IGNORE flags for write and young, then also > create a flags macro for the common case? > > #define FPB_IGNORE_COMMON (FPB_IGNORE_WRITE | FPB_IGNORE_YOUNG | \ > FPB_IGNORE_DIRTY | FPB_IGNORE_SOFT_DIRTY) > > It's not a hill I'm going to die on though... How about we make this function simpler, not more complicated? ;) -- Cheers, David / dhildenb