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Wong" , hch@lst.de, willy@infradead.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, Andrew Morton , kernel@pankajraghav.com References: <20250516101054.676046-1-p.raghav@samsung.com> <20250516101054.676046-2-p.raghav@samsung.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: <20250516101054.676046-2-p.raghav@samsung.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: w318ZsnnSkH4rOvex-B_DOMFG5_2KU1Z2b8AsN6YDzo_1747398067 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: y661j789h9de9dd5zc3mmru6wxh314p8 X-Rspam-User: X-Rspamd-Queue-Id: 590B918001A X-Rspamd-Server: rspam06 X-HE-Tag: 1747398070-10475 X-HE-Meta: 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 muYYki7R 9HPfuWdU4P12QHUNA7+QzJ8kv7jKXDoel942UlAb4wEHVrui0DPtgydfvWS6eHeWpXFRuowxq2D+nSbFLk/TW1MFgGELsWKIkMnwFu1S1snm6pr8NOjeBek7eCAT0hfPppli5u26i4omixBAKoHJCK5xzYSfCSA25UU4dDyHtMLYGRRhF11f6pJZq8I8EsZUM3wm3DqZalp2zJcNOeOMyJtZHS890h0iLXbcDhxmUoVQ6qzarl9DsxG0cb4Cxf1pgFRwWawHQzPm8wntRXCHXc6de//43zqFvIFV/8d/bG83NDCpBokYc4+IyDB7lbA8EQBT1QliXtAz2IFssxHLnciFufIgF15KVsqc0qsB/vXSHAAtcmzrqhlr6Go3NqiCxeoJvOcQ9S7huYISauYfVbxCEaw== 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 16.05.25 12:10, Pankaj Raghav wrote: > Introduce LARGE_ZERO_PAGE of size 2M as an alternative to ZERO_PAGE of > size PAGE_SIZE. > > There are many places in the kernel where we need to zeroout larger > chunks but the maximum segment we can zeroout at a time is limited by > PAGE_SIZE. > > This is especially annoying in block devices and filesystems where we > attach multiple ZERO_PAGEs to the bio in different bvecs. With multipage > bvec support in block layer, it is much more efficient to send out > larger zero pages as a part of single bvec. > > While there are other options such as huge_zero_page, they can fail > based on the system memory pressure requiring a fallback to ZERO_PAGE[3]. Instead of adding another one, why not have a config option that will always allocate the huge zeropage, and never free it? I mean, the whole thing about dynamically allocating/freeing it was for memory-constrained systems. For large systems, we just don't care. -- Cheers, David / dhildenb