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 0A30AC982FA for ; Wed, 23 Sep 2026 08:46:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E2C0D6B0088; Wed, 23 Sep 2026 04:46:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DDD136B0092; Wed, 23 Sep 2026 04:46:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CCC116B0095; Wed, 23 Sep 2026 04:46:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id ADD6C6B0088 for ; Wed, 23 Sep 2026 04:46:09 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id C17081C3436 for ; Wed, 23 Sep 2026 08:46:08 +0000 (UTC) X-FDA: 85244394816.09.C701B72 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf08.hostedemail.com (Postfix) with ESMTP id F3D6A160004 for ; Wed, 23 Sep 2026 08:46:06 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="iMlX/Y/J"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf08.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 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=1790153167; 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=PwZF3pqAeMznwbepH5UUc0GjovbxR4bX9vcY1/GYfgw=; b=kx/nJn1DepE4qhtNy4TuetflSBS9ID0gTQJurZ7Jrm9I7Tn1tUMbs2O6mO9JDsPLICdfoF +mZ8BElMoNqRqXpg8shYzIHc6iXkmQSsgQZlGR56jYIJC37QsGDPXSx/pJuOewdDqrnJ6s 5V7om0+IwVGXKkfW6ERvFpu8cDqZ0Vk= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="iMlX/Y/J"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf08.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790153167; b=3gsmds4RXelcp5S/zrTycRqgLsXzZjiF2AeiOTdE03D40fCwiso7T3oaHk52+z2ToCnOq9 9CjOZuA80eilsvL5VRp43/xYb31ei7O8OAxp5zrsLfaQcYI16qPjukk+TR+pfK7KlQm4Ga 4/WWUIImmxU5ycZ+0Im9CBr7QVlvOYs= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 1F91541147; Wed, 23 Sep 2026 08:46:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E68911F00893; Wed, 23 Sep 2026 08:45:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790153166; bh=PwZF3pqAeMznwbepH5UUc0GjovbxR4bX9vcY1/GYfgw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=iMlX/Y/JtwSu4cblQ6iLw2qW0e3IKyVInfxKJfA7BRoK/pTyJ4S+EDCwf3WlO2yI6 ZMbKchOUQs6OzPlv6jnOnAFLMx2aX2yyJ4WIdCXkYXviXnt3S8QE2R7tMcyqyjh8rc D4YgQrB3UhOYtmXzHvKNBpqHyocQXqJnPewl5zg0aGtqvU/ZGIQ9ZTXHbd8dp3LwaO i/iIM+R+GD+O4G+3sJKba/ZRRZEkamytqnHX7jbxqcAlQeXOwGsRNUVKWYsrpYzEGc xDRsh1rc5dJlzI+7Op1ib6nlgpPzfyKS4T3MLSAsHl0DQtb7fEC+vWuK50S+36E0Ph m1Efg+L3WOhow== Message-ID: <9dcde7e4-dadb-4644-9dff-7fd8a26e29a6@kernel.org> Date: Wed, 23 Sep 2026 10:45:33 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 00/12] mm: make userland page table freeing RCU-safe To: Andrew Morton , "Lorenzo Stoakes (ARM)" Cc: Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Guo Ren , Brian Cain , Geert Uytterhoeven , Dinh Nguyen , Simon Schuster , Jonas Bonn , Stefan Kristiansson , Stafford Horne , Rich Felker , John Paul Adrian Glaubitz , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Russell King , Vineet Gupta , Michal Simek , Chris Zankel , Max Filippov , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , "David S. Miller" , Andreas Larsson , Richard Henderson , Matt Turner , Magnus Lindholm , Catalin Marinas , Mark Rutland , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Madhavan Srinivasan , Michael Ellerman , "Christophe Leroy (CS GROUP)" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jason Gunthorpe , John Hubbard , Peter Xu , Yoshinori Sato , Shakeel Butt , Jonathan Corbet , Randy Dunlap , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-snps-arc@lists.infradead.org, linux-arch@vger.kernel.org, sparclinux@vger.kernel.org, linux-alpha@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-um@lists.infradead.org, Hugh Dickins , Qi Zheng , linux-doc@vger.kernel.org References: <20260922-rcu-pagetable-freeing-v4-0-fe1ad1f1e303@kernel.org> <20260922160021.a2fc65d05d9b867a141e5457@linux-foundation.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: gyy8w116ijk1rt1d5t5pnixkob3ak7by X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: F3D6A160004 X-HE-Tag: 1790153166-379100 X-HE-Meta: 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 E0FNIVUI lQ26+rkfy9GM/ssRebSe3mhH5Y+UkTHHL/LYnJEgZW7483VbB60GFEDXydydXl+yUzlOLOf3wpqyt+8m4qTMqp9xrYaEDbpodBCildBB8U0i59XLOE/GqLVyNSvMwiS51kfa2GxYofHOzcqZ5spAvmseE50CYroHetqQdLFq6/yz/hmqA72dSKsN+2aBKG8kDj4AtBXKmp9GRB/3+Qw1lvKg3xDYmhSx7chN7jCmsbxKX0fOFUujdnIlbY6HUIrFBCFRyFF0idh+8J14jKv7IYbMEK2MqUnBSEZdgt3GdjCgwuhG06DeDkVk/XraaPNQPfIzmVBUW4/MhBBWfV6lm1okwzbggQEOyQRVdSHz9m4FuLA0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/23/26 01:00, Andrew Morton wrote: > On Tue, 22 Sep 2026 16:35:31 +0100 "Lorenzo Stoakes (ARM)" wrote: > >> The majority of architectures in the kernel defer page table freeing until >> an RCU grace period has elapsed, this series converts all remaining >> architectures to do so too and eliminates CONFIG_MMU_GATHER_RCU_TABLE_FREE >> altogether. >> >> This is important because it enables safe lockless page table walking under >> RCU alone. > > Do we have reason to believe that anyone is seeing any effects from > their arch's failure to rcu-free the page tables? > > This sounds like a rather long-standing wart, yes? > > The patchset is thinly reviewed and mm.git is bursting at the seams > again. I'll play wait-and-see on this series. Do we want to nudge arch maintainers to review? -- Cheers, David