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 E090CEA4FB3 for ; Mon, 23 Feb 2026 12:16:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 263D06B0089; Mon, 23 Feb 2026 07:16:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 211CB6B008A; Mon, 23 Feb 2026 07:16:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F3AB6B008C; Mon, 23 Feb 2026 07:16:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id F07CB6B0089 for ; Mon, 23 Feb 2026 07:16:15 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 9C29BB2DF3 for ; Mon, 23 Feb 2026 12:16:15 +0000 (UTC) X-FDA: 84475618710.20.AD11D84 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf13.hostedemail.com (Postfix) with ESMTP id 81F712000F for ; Mon, 23 Feb 2026 12:16:13 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="AnKNXr/g"; spf=pass (imf13.hostedemail.com: domain of kas@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=kas@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1771848973; 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=efjFtIPt4Ps4MfEO7d1agn4Edh2fwbMMFBWjRDjmaHc=; b=sTia27XgQs/KhIvIXKwwFGqc1rJGdD3o+gmttft13vkhRZdPpflMFn13zwq2tzrcwGWI0b 6xfd4X06hb1zy6+k2N3hxlb1m0l4dLQr5qHDja9179GZdxUGLlegNcO+78z5M4pOvtXYhl g4vxBR+vfMDP4ELk9Ga8U3ImtGfHf9U= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="AnKNXr/g"; spf=pass (imf13.hostedemail.com: domain of kas@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=kas@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1771848973; a=rsa-sha256; cv=none; b=UH5qdE7NZQwJtruQPCTF6Y0/AKcHVmPGReUZ6+Q0NEzLMP/vnCFmjvSXLTGP7TkOlLxKhk GiltpxsmEckYd8O7QfmhUC+zfIvPt3GFUWckjq610lzInvfJse98tZR685AkPEhLPaEcwv YcOeQUL1Kn5OVAzk3X3aJ7USL5d3CQk= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 7B15F43585; Mon, 23 Feb 2026 12:16:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3CD7C116C6; Mon, 23 Feb 2026 12:16:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771848972; bh=9iO7p5jg3rewS1pOAtzAVmxybx20UVJaapbeUxgXQSk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AnKNXr/g8SOiAEQ7iFEoVxky9iLTyzle0GbrxihA80NU1Em9Y+1tUN6LemjqRRW5v VWtZ/sQgG7bBiItGF1u1UniBiVwkRBMmpOJBMCGIBQHrS/0WWthZkJ0BEqIc8YGom6 g2tyf7qZsjdaX53WpW6T/0i5JiumL6lT//4FJEC5E2acdEZWIdP7116rTd+9+ybexU oDF8FqnEOMvlMgaB2R1gy0rtvQ5HfELwPHLtvCSIB/fp9MDNFmmBwV4M82cLVSeizg ANPVu5Y/ZNp6DkLcd0f4ekgEMBXc6Q80PMDPWGaM6iC1XQQL+XcRziATnaQ7r1Q0aq RZiROc/LZkvlQ== Received: from phl-compute-12.internal (phl-compute-12.internal [10.202.2.52]) by mailfauth.phl.internal (Postfix) with ESMTP id A8DA7F40069; Mon, 23 Feb 2026 07:16:10 -0500 (EST) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-12.internal (MEProxy); Mon, 23 Feb 2026 07:16:10 -0500 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgddvfeejvdduucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf gurhepfffhvfevuffkfhggtggugfgjsehtkeertddttdejnecuhfhrohhmpefmihhrhihl ucfuhhhuthhsvghmrghuuceokhgrsheskhgvrhhnvghlrdhorhhgqeenucggtffrrghtth gvrhhnpeeigfdvtdekveejhfehtdduueeuieekjeekvdfggfdtkeegieevjedvgeetvdeh gfenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehkih hrihhllhdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqudeiudduiedvieeh hedqvdekgeeggeejvdekqdhkrghspeepkhgvrhhnvghlrdhorhhgsehshhhuthgvmhhovh drnhgrmhgvpdhnsggprhgtphhtthhopeefgedpmhhouggvpehsmhhtphhouhhtpdhrtghp thhtohepuggrvhhiugeskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepkhgrlhgvshhhsh hinhhghhesghhoohhglhgvrdgtohhmpdhrtghpthhtoheplhhsfhdqphgtsehlihhsthhs rdhlihhnuhigqdhfohhunhgurghtihhonhdrohhrghdprhgtphhtthhopehlihhnuhigqd hmmheskhhvrggtkhdrohhrghdprhgtphhtthhopeigkeeisehkvghrnhgvlhdrohhrghdp rhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrgh dprhgtphhtthhopegrkhhpmheslhhinhhugidqfhhouhhnuggrthhiohhnrdhorhhgpdhr tghpthhtohepthhglhigsehlihhnuhhtrhhonhhigidruggvpdhrtghpthhtohepmhhinh hgohesrhgvughhrghtrdgtohhm X-ME-Proxy: Feedback-ID: i10464835:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 23 Feb 2026 07:16:08 -0500 (EST) Date: Mon, 23 Feb 2026 12:16:03 +0000 From: Kiryl Shutsemau To: "David Hildenbrand (Arm)" Cc: Kalesh Singh , 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 , Matthew Wilcox , Johannes Weiner , Usama Arif Subject: Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86 Message-ID: References: <915aafb3-d1ff-4ae9-8751-f78e333a1f5f@kernel.org> <17c5708d-3859-49a5-814e-bc3564bc3ac6@kernel.org> <32ed82dd-62c3-4a5c-8bae-9465afd7e75f@kernel.org> <06684dc4-3902-4452-824a-ee2064314d24@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <06684dc4-3902-4452-824a-ee2064314d24@kernel.org> X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 81F712000F X-Stat-Signature: xmfdfj9yqetear1ewe9g57dn7j1yztd8 X-Rspam-User: X-HE-Tag: 1771848973-285977 X-HE-Meta: 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 bURS0WMu 3xlYflKUupZr9SBgJYeYSjyoev2KFkOlwNKxT4bIFLilpMGnOum0VZy1ntavm4gF/FOcFztuksZ32TAtAeVRa63ScvsUUx7bzdUsZnYEwTLESp+RW/DFapsMswNaenUBVNyBLWO0iC0mAKgwEutaAEstYUUe2F0qbY4bjjc5jrt4DyLbegFmjRbeKTJLIPC+EiCxVDm2AswrePlxr3rF/yn4l8XJP7mWrj2Hu3Vv7ld6pl53Axqkr3i+WdEPMRQbuCYkkZBenxakOdTx/DVmrCSbjt5HmQYr4LZd7 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 Mon, Feb 23, 2026 at 12:27:33PM +0100, David Hildenbrand (Arm) wrote: > On 2/23/26 12:13, Kiryl Shutsemau wrote: > > On Mon, Feb 23, 2026 at 12:04:10PM +0100, David Hildenbrand (Arm) wrote: > > > On 2/20/26 20:33, Kalesh Singh wrote: > > > > On Fri, Feb 20, 2026 at 8:30 AM David Hildenbrand (Arm) > > > > wrote: > > > > > > > > I think most issues will stem from linkers setting the default ELF > > > > segment alignment (max-page-size) for x86 to 4096. So those ELFs will > > > > not load correctly or at all on the larger emulated granularity. > > > > > > Right, I assume that they will have to be thought about that, and possibly, > > > some binaries/libraries recompiled. > > > > I think backward compatibility is important and I believe we can get > > there without ABI break. And optimize from there. > > > > BTW, x86-64 SysV ABI allows for 64k page size: > > > > Systems are permitted to use any power-of-two page size between > > 4KB and 64KB, inclusive. > > > > But it doesn't work in practice. > > Even in well controlled environments you would run in a hyperscaler? I have not invested much time into investigating this. I intentionally targeted compatible version assuming it will be better received by upstream. I want it to be usable outside specially cured userspace. 64k might not be good fit for a desktop, but 16k can be a different story. -- Kiryl Shutsemau / Kirill A. Shutemov