From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793011130; b=wqA0VjXeive9Qt+wF9cDBJWThYcl05IzV10m4LoRdB1HGnO1gU1jvxXfQgTMyLEF4BUc UHKsgzh1GUI6kZS9dlmt276cre38MiGFoY4C659w2yfQAmNvoC+vTwLQQAeZmxSvyzI7c SLh2i0KDWsEBiZnydXNEIQ1hud4Rt3ZbC1mmiPS0k5+ZlHbgut9Uc2iscWLJKfCl3UVxA 3ZcwTaP3JDrXZOi4xJHHeZHjbHKb/8SlbXfhTbbI7ur7epDRfi0ELLXCuDbby8gydcZku z0+DanB5YMGP970ul9x0AjU0Y92crrMpUHHpDc5hBTinz/JlXW2lY+Q5HxR85Rt5EGA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793011130; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=/BLhE6A843KDT8+y0mtaljR3lPY00tdB/4nQapDfY8E=; b=3J7fSOQL8q+gM2Qf5MJgKx4BzOFHFAohF5ib++s2DXvHP0aJz8BJWgKrwUZciYCiK1FH QcRGfTtTLp/m6vgRtq9jLTgiCtMQUh3UaRgPhGcF5W2TPqaM9grveW0kr/ZGbLYbP5ejG pno9lN3MhghWpMjteynLGzJDbYnwC9w5OoWHxFHQcCsQQkC7hxokADOTSpKmseTjA4Fa0 3XDcNPYlmjz6PE8YE0n8qEZ7IXPaiMs6nQGUc34PHPnLUYVMCUNjoshI3+vaCaOuuTX1r YAi0B8ADxyyQLylh6rWd5iauIRfHZ2EvbZT7kpktPyKDMSl4/MVP/r5osbgxL3hZ4Yg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DAokXhrI; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F3647606A31A; Mon, 26 Oct 2026 10:38:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DAokXhrI Received: by smtp.kernel.org (Postfix) with ESMTPSA id 431F41F01825; Mon, 26 Oct 2026 10:38:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793011129; bh=/BLhE6A843KDT8+y0mtaljR3lPY00tdB/4nQapDfY8E=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=DAokXhrI31jxzYuScbo35XEhEcxr79cZ8kAnkbToxT9/ue8/BqmP4QcZTyIgwFr4s WrQDTnU4Z7PLHHPOo7V1mQ9uEoB0nciISo4EFJJ5JwATLvAz8R+NJCvNCfvC07PDBK Row6ghd03Z7AzOD7m5dxYks0nXQoMHfyZL5kIGiP4JtbjhQMcMmgHLMAEOFv0w2VQ2 pPcjKjSp7tIivkSDIrkJG8v1k3EurLoxIGf2HGUR4RdOMB2QPDN+XQ3T4jdZifymE2 SKGIZPqarIgIR9sUUWwS9qu2oz3PnM/GKk3Ufmwg/dbFuX2cftxjpQh2XPrlUlhZZD oksob1U8ckOHw== Message-ID: <103481d2-f75a-4982-b9a1-3592cda8267a@kernel.org> Date: Mon, 26 Oct 2026 11:38:42 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] mm: generalize PUD page table allocation To: Muchun Song , Andrew Morton Cc: Muchun Song , Arnd Bergmann , "Mike Rapoport (Microsoft)" , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , linux-mm@kvack.org, linux-arch@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20261014035910.687847-1-songmuchun@bytedance.com> <20261014035910.687847-4-songmuchun@bytedance.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20261014035910.687847-4-songmuchun@bytedance.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/14/26 05:59, Muchun Song wrote: > The generic PUD allocator assumes order-0 page tables and zero-valued empty > entries. MIPS and LoongArch need pud_init() to install their invalid > entries. MIPS also uses PUD_TABLE_ORDER to describe the allocation size. > > Default PUD_TABLE_ORDER to zero, honor architecture overrides, and invoke > pud_init() from the generic allocator. MIPS and LoongArch can then drop > their duplicate helpers and use the generic constructor handling and kernel > ptdesc marking. > > This also switches their user PUD allocations from GFP_KERNEL to > GFP_PGTABLE_USER, so they are accounted to the active memory cgroup > context. Allocations for init_mm continue to use GFP_PGTABLE_KERNEL. > > Assisted-by: LLM > Signed-off-by: Muchun Song > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David