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[79.242.59.227]) by smtp.gmail.com with ESMTPSA id bs15-20020a056000070f00b0033e9f6997c7sm3448929wrb.66.2024.03.12.09.32.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Mar 2024 09:32:38 -0700 (PDT) Message-ID: <37ed1ddd-f1d0-4582-b6c5-2f4091dc8335@redhat.com> Date: Tue, 12 Mar 2024 17:32:37 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 00/15] Fast kernel headers: split linux/mm.h To: Max Kellermann Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, willy@infradead.org, sfr@canb.auug.org.au References: <20240312094133.2084996-1-max.kellermann@ionos.com> <58fbe42a-3051-46bf-a3f9-d59da28a9cd7@redhat.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-Stat-Signature: yg1sjkbd5pprz957xb9ofx9fnthn43b1 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 57E64C0026 X-Rspam-User: X-HE-Tag: 1710261163-803857 X-HE-Meta: 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 KpkcYN7R jq7vpbOXP9XrjtPrkNYJA9N4sIiWKnXT56LsBIGTy5g0ySE5BoEr8j9NQJaMreKY/Bs7U52738Qe3HU+TLNE28dtrJ6pGg1Zdczp1TvLGmHB+2uhc6wHmcR1L2lWiuF4HFB4zSOZYnBdE+3rWzR/5jMBvqDtmW8hhj4a6 X-Bogosity: Ham, tests=bogofilter, spamicity=0.016165, 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 12.03.24 17:27, Max Kellermann wrote: > On Tue, Mar 12, 2024 at 5:10 PM David Hildenbrand wrote: >>> include/linux/mm.h | 583 +----------------- >>> include/linux/mm/devmap_managed.h | 37 ++ >>> include/linux/mm/folio_next.h | 27 + >> >> Isn't that a bit excessive? Do we really need that many folio headers? > > It would technically be possible to have fewer headers by merging > several of those headers back into one, but then the dependencies will > be heavier, and eventually we'd be back at the large "mm.h" mess that > I would like to get rid of. Just curious: why? Usually build time, do you have some numbers? > My patch set constitutes the balance of "not too many headers" vs > "small set of unnecessary dependencies for each including source file" > according to my taste. I'm not against splitting out stuff. But one function per header is a bit excessive IMHO. Ideally, we'd have some MM guideline that we'll be able to follow in the future. So we don't need "personal taste". For example, if I were to write a folio_prev(), should I put it in include/linux/mm/folio_prev.h ? Likely we'd put it into folio_next.h, but then the name doesn't make any sense. The point I am trying to make: if there was a single folio_ops.h, it would be clearer where it would go. Just my 2 cents, seeing one-function-per-file headers. -- Cheers, David / dhildenb