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 D023BC88E77 for ; Wed, 16 Sep 2026 02:01:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1050A6B0092; Tue, 15 Sep 2026 22:01:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0B72A6B0093; Tue, 15 Sep 2026 22:01:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EE75F6B0095; Tue, 15 Sep 2026 22:01:38 -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 B60BF6B0092 for ; Tue, 15 Sep 2026 22:01:38 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id ADC021C292A for ; Wed, 16 Sep 2026 02:01:37 +0000 (UTC) X-FDA: 85217973834.06.FDF77BB Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf12.hostedemail.com (Postfix) with ESMTP id E3EEB4000A for ; Wed, 16 Sep 2026 02:01:35 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=HA4IrxR+; spf=pass (imf12.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789524096; b=IN/ebRBRXoyCseGIRXvFUOSvAVuK/wOxjEIBaRWhOGMt54Q14vXNZ1gc/MKBNSo3XeOp1A +/9dzNZY0dW3BSkjPHehaLoMmeCdLGQeJytgH4uTxX8qT5pZT+/Eyoowurs4AozEI7ISnp I3UQU1iivqPXxxTm2sUU1g7EnNG/x6k= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=HA4IrxR+; spf=pass (imf12.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789524096; 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=Kq4nX0CZWZvbBl1ewxdrR8njTtxJd2HKKhLZ4yZoin4=; b=naoBSRCiwplODOr0O16dPB+OMfveyWRvhroZDrvNUT88wsrKIeLkmSvKnbKTpkwlLemHaz OPk7tMdyRjdr0LinV07XFsUbEjLEOnQOsSRJbAMlnbz6cRUsHQyfDfRoR800+RvG2Ksr/g htw0pRx5VRP39VEBaeI03Xqa/3EQvms= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id CDE3560214; Wed, 16 Sep 2026 02:01:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E999D1F00893; Wed, 16 Sep 2026 02:01:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789524094; bh=Kq4nX0CZWZvbBl1ewxdrR8njTtxJd2HKKhLZ4yZoin4=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=HA4IrxR+bH6KFYi5TWsVFFRj5NN/KsmXWn+L2rcKXslNm+h4O1+C0Mz1TX/mnbSd5 wNlo1vs7L/RwOu/p4JC+a32HO1/edlho+RmyG7M/c8w2xQw4dUW63KjVSNntMUP6xo zHIhd6HWzSLYzzfxhv0JalmDYIqgVcBuZA1Pa2/U= Date: Tue, 15 Sep 2026 19:01:31 -0700 From: Andrew Morton To: "Lorenzo Stoakes (ARM)" Cc: David Hildenbrand , 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 , Yoshinori Sato , 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 , 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 Subject: Re: [PATCH v3 00/12] mm: make userland page table freeing RCU-safe Message-Id: <20260915190131.adee185f2ce04a8ec821489c@linux-foundation.org> In-Reply-To: <20260911-rcu-pagetable-freeing-v3-0-7b8c86103821@kernel.org> References: <20260911-rcu-pagetable-freeing-v3-0-7b8c86103821@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: E3EEB4000A X-Rspam-User: X-Stat-Signature: wd93kmnap8dcfw8kmshhux5ifpo9ccpm X-HE-Tag: 1789524095-495377 X-HE-Meta: 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 eAdVfEdR LfXx5+THod8lXitLhK9XoDvMd8M+t1VW6zYWCRrH5r7VPYOE45E4omX8vdAJniflis9eLfqGkF7HqISudaIwri+F1RP2X3mzu4JfzCnI+NN8qZ03f8FHrKEHwvlwjeEhkAfytL2r5LNP7+TGc658jGECI0GZQI5Ha6fn+JZ16wI2z2xKW4qzwOVYFCc8nZI5XkgxRgxPPR/PnfR3tgIp2ByB40tSilYxWR5ge9Qp+s2gwIJ7QG6ZsHh4TMapY0YhpWXzAS7aNnwT0mQTqPpDGI8otjcSBgBfUbfzw30sFYdl/bRC+PID+Wj3Xo+VdGVljfeIqiZSOQGTZbgQVg8wd5YwdKar/rsrrycaC Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, 11 Sep 2026 20:36:47 +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. Thanks, I've updated mm.git's mm-unstable branch to this version. > v3: > * Added Kiryl's tag to series (thanks! :) > * Corrected commit message, comment indentation in 11/12 as per Kiryl. > * Corrected 12/12 documentation as per Kiryl. Here's how v3 altered mm.git: Documentation/mm/process_addrs.rst | 4 ++-- include/asm-generic/tlb.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/Documentation/mm/process_addrs.rst~b +++ a/Documentation/mm/process_addrs.rst @@ -541,8 +541,8 @@ We establish basic locking rules when in after an RCU grace period has elapsed. However, any entry found must be revalidated after the page table lock is taken (such as the :c:func:`!pmd_same` recheck performed by :c:func:`!pte_offset_map_lock`) - before it is acted upon. Changing an entry always requires the page table - lock. + before it is acted upon. Changing an entry requires the page table + lock and one of the locks that excludes teardown (mmap or VMA lock). * Reads from and writes to page table entries must be *appropriately* atomic. See the section on atomicity below for details. * Populating previously empty entries requires that the mmap or VMA locks are --- a/include/asm-generic/tlb.h~b +++ a/include/asm-generic/tlb.h @@ -151,8 +151,8 @@ * Page directories (__p*_free_tlb()) are always freed via tlb_remove_table(), * after an RCU grace period (see mm/mmu_gather.c). * - * This serialises against software page-table walkers, including architectures - * which do not use IPIs for remote TLB invalidates. + * This serialises against software page-table walkers, including architectures + * which do not use IPIs for remote TLB invalidates. * * An architecture is expected to provide __tlb_remove_table() (see * HAVE_ARCH_TLB_REMOVE_TABLE) or use the generic __tlb_remove_table(), which _