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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 27E62CD3423 for ; Fri, 1 May 2026 18:06:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 661C26B0005; Fri, 1 May 2026 14:06:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6130C6B0092; Fri, 1 May 2026 14:06:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 501AB6B0093; Fri, 1 May 2026 14:06:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 3E4936B0005 for ; Fri, 1 May 2026 14:06:05 -0400 (EDT) Received: from smtpin10.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C018DC0976 for ; Fri, 1 May 2026 18:06:04 +0000 (UTC) X-FDA: 84719629848.10.A9A3E45 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf02.hostedemail.com (Postfix) with ESMTP id 11AFB80003 for ; Fri, 1 May 2026 18:06:02 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=VKpbfCPo; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1777658763; 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=YFJO3kncGTLksH7oA9LcPI2XxoKPymWsz0S2X0yQsCY=; b=cTW64IbRNqmHwKX21RVkIVBtxaLfZJ//qKy3iTnuYezzlLbOWxMxSLAG7SXttdXlmnJLBp B6Swsi+26SYxDQKc/0d4WOT1lZX701wlKWmDPUSddeE6LOoOgRyRI0om/hlE6yoFWYGv/I TtaiK+PAiR2HaZkRDDWsqRzLZ57+7Nc= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1777658763; a=rsa-sha256; cv=none; b=N5bQrdMgKdMSEUigG7TZrnlAAdGz0iH0Ahk0PCZWd2xlqrL0mdhjBE4Kd330hQBxgZnQK+ ZSdlH/FJ5HMBDd4NvvmAvHAx/8Z/xPCfV5G4jUGeMSjFmRdZMTDy/iO0d8x3kcJdOg0r2x CUuQsuZ9QHjw5hrARgFzEdFjhEte5ms= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=VKpbfCPo; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 4B8A5600CB; Fri, 1 May 2026 18:06:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4ED93C2BCB4; Fri, 1 May 2026 18:05:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777658762; bh=fPmJ2/Qb7QpFKxM1j5fPVHDJeKRS6/mwonl0EZ5/tEg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VKpbfCPoBuOY0D6cQgJaK30uRMoPNJJ8fXi/i2N+ED9hzWASMbBbgfLQfbkBjQczB mvadihsrsFi6vquYmNxB7GHpR0aG56bBaPVtgOvRbLZ0Es2OOAh81/hMrmUAhI3cal PNA/UiUBzoor39onccj2SY7jtXS3CqLLwknXD9JfdEqax6nk0oKRXu2etncA0zFTFg oaDKApOYtj0q7iC7p9oFXS4NsgnDx7nU3ZZsVu6s36pF943OertFMvMP3fFCwLmbab A7Y+MQo7wTAjVXmphxN/18Nkt75YxPhsdsh77DXVmfj3ZOxDMxQyOFKNK88lQ30Wen sgznQQa/BIpwQ== Message-ID: <3a599186-6ae5-4175-8de0-1826a045222c@kernel.org> Date: Fri, 1 May 2026 20:05:54 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86 To: Matthew Wilcox , Kiryl Shutsemau Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Johannes Weiner , Usama Arif References: 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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 11AFB80003 X-Stat-Signature: kw6g6rinumb6j8z8r61fkbiypshm8oc3 X-Rspam-User: X-HE-Tag: 1777658762-699476 X-HE-Meta: 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 uGqwhpMt dKDdSrfB810MCIwF9tmLT3sK8qGXI6Mqh/YQYusL6W2J18WtMy2vOSV+RLFq8H9oDdN0eKTOFArIyMcSovIzOqukdymUFBz4acaAEhPRaM331Um1xgEwZjopipvKMpZIdTTE+AX7wkzqXXsW1DlI9FaU4GPnUUGZnJzp5S2PNgZJHUm8U2PQOP157GzeB1vfzFN+gF1NSClJnTvPf5H14vjSnRin+bRjIM94fk5n9feOd73kBPOSwNC4K/B9Eho1mIoMG Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > Fourth, we change the unit of the lookup in the maple tree from being > a PFN to being address / 512 (or whatever size we want to use as our > minimum). > > Now we can have memdescs for an arbitrary power of two which means we > can ditch all the awful code from ppc/s390 page table handling where > they try to share one memdesc between several different page tables. Having a memdesc describe a smaller piece than a page sounds like the way to approach this cleanly. A lot of work, but sounds like the right long-term vision also when it comes to having folios that are smaller than a page. -- Cheers, David