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 DA04EC79F82 for ; Tue, 8 Sep 2026 12:33:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CFD546B0095; Tue, 8 Sep 2026 08:33:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CD50B6B0096; Tue, 8 Sep 2026 08:33:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BED886B0098; Tue, 8 Sep 2026 08:33:54 -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 98F7B6B0095 for ; Tue, 8 Sep 2026 08:33:54 -0400 (EDT) Received: from smtpin19.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 3B9931605CA for ; Tue, 8 Sep 2026 12:33:54 +0000 (UTC) X-FDA: 85190536788.19.FB1ABF8 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf27.hostedemail.com (Postfix) with ESMTP id 821B14000D for ; Tue, 8 Sep 2026 12:33:52 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=llQX4MW5; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788870832; b=JjJkrr6myxyZ0yJVPM89JGzbH9xnOy4s+rq8e3QlpuGi36ggEUYpOiRytVoi1k1ZSzfBNR nD8FBcwqS09t96FgDJ4RT4mnJLg+tVXc6u5T9C29e+y3FthCv2Pgxwv1HP/ix4AFo7ySRK 00G1sD+RSeI4TtyWrcFnUuGgw7N238Q= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=llQX4MW5; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788870832; 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=+MMfaleDm2ce+ucIbxA7OEsrjCLcZrtuUhG+cgJq5Q4=; b=wzrivtyOjkCtffH7e9oWvnlhGA1gFeSFKMEvRlbZhb0sFJT4JsQBHqI64ShX9dtGjKYM+b O4HVrbp7pnh3PIPQZTu8+2pEATwe5jD6t4YHUP3MwK4QxL2E0q0K8ic0zZSMziCYn5tp1t YrNtGfaB08MLbPpiv2fuIafXh+IbVAc= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 01B83601DB; Tue, 8 Sep 2026 12:33:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65E821F00A3F; Tue, 8 Sep 2026 12:33:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788870831; bh=+MMfaleDm2ce+ucIbxA7OEsrjCLcZrtuUhG+cgJq5Q4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=llQX4MW5oCBsfa1bNRnJU4DEvCvhPnI34ch0k0V9oeZcYx+cu4YdByza/2aSoCr/G CfKP5R2/194SkhjsLiDuF4q4rjsOGl5KRdxEMwR0IXQhsFfIOyBe59X4G7g8LM/dfc yD0HDu8VUB8mzYeVQsTdJd8B4y8T4ec2nV110GkhlYVT3ver1LeS+kzS1s1vK8HQ7i 4s4fqrS7vIzDShvOFV+AdxVL+6R/SgQtPPZla750Bv5wgpnWFIWUQ85x5zEui6gtNH f+OEXJBeMwjnPby8KeTTneiAnFyOfMUP8dx9E7U0Q3GWJOHAXQDVVBIovssZ0RTYcT 7IV4kIHKxD9cQ== From: "Lorenzo Stoakes (ARM)" Date: Tue, 08 Sep 2026 13:32:12 +0100 Subject: [PATCH v2 03/12] mm: enable MMU_GATHER_RCU_TABLE_FREE for MMU riscv MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260908-rcu-pagetable-freeing-v2-3-1f60b64e878e@kernel.org> References: <20260908-rcu-pagetable-freeing-v2-0-1f60b64e878e@kernel.org> In-Reply-To: <20260908-rcu-pagetable-freeing-v2-0-1f60b64e878e@kernel.org> To: Andrew Morton , David Hildenbrand , Zi Yan , Baolin Wang , "Liam R. 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Peter Anvin" , Arnd Bergmann , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jason Gunthorpe , John Hubbard , Peter Xu Cc: 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 , "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1550; i=ljs@kernel.org; h=from:subject:message-id; bh=mgr1uJE8DIP+D2hAcn/4VQ8oaO28pfdyIohSciDSfkU=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLIWMETbXblq+9Ih1fKpoW6rqWr7Fish54Yr7Y/+bb81/ 9D7DD6FjlIWBjEuBlkxRZbnX8T3B4mEzeu84O8GM4eVCWQIAxenAEzE9B7DX6EdDA/kVnP83WYW d265mtIhyUU/Z/HO55j4ucyQ+eneN2aMDFNOXFunsOPssb3qfSlrPCwO3U+8JzlN3On28eWhk+y WhbEAAA== X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 821B14000D X-Stat-Signature: 6c5cte9jic499pwk5s7awen7p3u6peeo X-HE-Tag: 1788870832-480576 X-HE-Meta: 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 5ShcEhyy VOl044nrcbF0IKoQsZsMVEoqa/FsgFWvKqhVM//ziJvgzMatrye3ETkZzSNW4sq+I0mDhaea2JIMiRvkUmUsNCQGk5iO06wF7Kcb2t2CKbpwgauRP0RzNPXTCNPF3GcbDVkA9OIRArS3rlbp9HKSI+MuEYuCDjDM+7Eq/llzornQRP6K8seAsW8dTLNxXpnelDIK1Lefnq8JUT6tiWXsO/AMd0xxpdx+cZVbxjYChPDbZpplundiDIcyNjp+CrwFH0MFWp33h6mZbGdaZzewVgyReW1pNYK9a93AGPt5Fa93U2emoUHByv6LZW0Aa2jz5x/BoAonTTv7WrxvIWowfChf2vGCpHe1IocP7jlIpFJsMKC5RFqFht/17wS4qrNvcuG4vRlk4dUqGYMHcKkFcG5ETpW3WUPq7w74YlStmNJXJDTOM2Sglteol7dRilB1uzsNmjP0wLNwzrpmwDdQQLGt+qOON37LpQHZAk7Um8O6NCko= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Currently riscv gates MMU_GATHER_RCU_TABLE_FREE on CONFIG_SMP and CONFIG_MMU. Commit 69be3fb111e7 ("riscv: enable MMU_GATHER_RCU_TABLE_FREE for SMP && MMU") enabled CONFIG_MMU_GATHER_RCU_TABLE_FREE for CONFIG_SMP, CONFIG_MMU riscv builds. This is expressly for the safety of GUP-fast walkers (CONFIG_HAVE_GUP_FAST is enabled if CONFIG_MMU is enabled). Naturally a single core system does not encounter issues with software page table walkers being correctly synchronised across cores, as there is only a single core. However, CONFIG_PREEMPT_RCU is still available on a riscv UP system, so for a future RCU-only page table walker, this guarantee is required to prevent concurrent page table teardown. All page table freeing is already done via tlb_remove_ptdesc() so the conditions of CONFIG_MMU_GATHER_RCU_TABLE_FREE are already met. This forms part of an overall effort to switch every architecture to this mode. Signed-off-by: Lorenzo Stoakes (ARM) --- arch/riscv/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 505eed4af932..3529ed1861ce 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -208,7 +208,7 @@ config RISCV select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN select LOCK_MM_AND_FIND_VMA - select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU + select MMU_GATHER_RCU_TABLE_FREE if MMU select MODULES_USE_ELF_RELA if MODULES select OF select OF_EARLY_FLATTREE -- 2.55.0