From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3CB5755820D; Tue, 22 Sep 2026 15:37:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790091442; cv=none; b=hicN0/Gh5PAfA9+0mDBDWt2LblfbDSIuC30IlPqMA8cRfAJoPSFb89/gMsDeRqn8xOaZZPDkXKPhnwvBU2yE10nM+jMoRxYjAfhHQup3Od9K0jiHaKWe5zRJJ4cDjPv64eg/sf6gwZRGI2TMfkfBjGdm/xJsCSXnOysXF3Qmrg0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790091442; c=relaxed/simple; bh=bwuaeHFGwuLQFcHN0hOhjdTFxvn+j0g8fIWNrCdz0hk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=k4w1LO0ZYceJOF3cfweE5kiUXuU3FuGJQkFQP7tt8Oruo7BhZnThrfZn8oQqayoQkuCR+0ON5Y8UuOMGLzz4yFVAolk67kctqPJD1F7Fd+70fO5gls0UskITGeU10NwuKI4ArCkf6GsU+moJ8A1SOpsp3lH0+jSgsIMvB9tZ9GY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A8I7oZL7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A8I7oZL7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F4FC1F00899; Tue, 22 Sep 2026 15:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790091440; bh=EytwztXVP9+HAqnBzZ3KHLRHej5X7gcr6/abe7XoyR8=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=A8I7oZL76bgc/K4OnZ0JyOMCleMrv8FdbRx4ZImWL6TzUOPy27OJNysbdg4leGGta Lx4vSFm7V5JKYxrVGD86zIiIioAiFtHv9yN3wsYYID68QpWVVMN3tQku4l98Qy4zgw qF27kTj7WZm0/RooazviLjtxmwgEqpzuJcU5c7iIeBV8ngO+1ipt0+uSiSCb1hYR9b FeqTZuRHz8OvBlBx/kNDAhn+A5qaMG/FK1Kz/HdRa6QnK91S6WhAahUdZR52ic+UQ6 m4kfJDCDMoP3ZT2i41bOmIUPh/ZPP4TnOLJOrrC+n/gp89K3MgMVpMT2NZUEDoQZj+ OSQ/pfkvGm+LQ== From: "Lorenzo Stoakes (ARM)" Date: Tue, 22 Sep 2026 16:35:33 +0100 Subject: [PATCH v4 02/12] mm: enable MMU_GATHER_RCU_TABLE_FREE for most 2-level architectures Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260922-rcu-pagetable-freeing-v4-2-fe1ad1f1e303@kernel.org> References: <20260922-rcu-pagetable-freeing-v4-0-fe1ad1f1e303@kernel.org> In-Reply-To: <20260922-rcu-pagetable-freeing-v4-0-fe1ad1f1e303@kernel.org> To: Andrew Morton , 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 , 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 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 , linux-doc@vger.kernel.org, "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=3613; i=ljs@kernel.org; h=from:subject:message-id; bh=bwuaeHFGwuLQFcHN0hOhjdTFxvn+j0g8fIWNrCdz0hk=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLI2Lch++epj9MNnHpEe9yYlHD30J+h8XF7vnb1CF/a1l 1Vpn6xe2FHKwiDGxSArpsjy/Iv4/iCRsHmdF/zdYOawMoEMYeDiFICJNO1n+J9tETupvXJjzarT rwX+hry6vcpP5urt1Q9MTtum66QcKIlk+B9bHRHH1mdsW7N44armiqcpC9oZ5195ZXdRTZPRdKv ybXYA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 Commit e3ecf7c7d082 ("mm: pgtable: convert some architectures to use tlb_remove_ptdesc()") updated a number of architectures from using pagetable_dtor() + tlb_remove_page_ptdesc() to using tlb_remove_ptdesc() in __pte_free_tlb(). This is meaningful as tlb_remove_ptdesc() allows for RCU page table freeing if CONFIG_MMU_GATHER_RCU_TABLE_FREE is specified. The csky, hexagon, nios2, openrisc, sh (except X2) and m68k-sun3 architectures all have 2 levels of page tables, so the only page tables ever freed by mmu_gather are PTEs, so this update suffices to ensure that every page table freed by the mmu_gather mechanism is freed under RCU. Therefore, update all of these architectures to select CONFIG_MMU_GATHER_RCU_TABLE_FREE. This forms part of an overall effort to switch every architecture to this mode. Acked-by: Kiryl Shutsemau (Meta) Signed-off-by: Lorenzo Stoakes (ARM) --- arch/csky/Kconfig | 1 + arch/hexagon/Kconfig | 1 + arch/m68k/Kconfig | 1 + arch/nios2/Kconfig | 1 + arch/openrisc/Kconfig | 1 + arch/sh/Kconfig | 1 + 6 files changed, 6 insertions(+) diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 4331313a42ff..80f89ef1d962 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -96,6 +96,7 @@ config CSKY select HAVE_SYSCALL_TRACEPOINTS select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select LOCK_MM_AND_FIND_VMA + select MMU_GATHER_RCU_TABLE_FREE select MAY_HAVE_SPARSE_IRQ select MODULES_USE_ELF_RELA if MODULES select OF diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig index b48491140013..d9b3fb86556b 100644 --- a/arch/hexagon/Kconfig +++ b/arch/hexagon/Kconfig @@ -23,6 +23,7 @@ config HEXAGON # select HAVE_CLK select GENERIC_ATOMIC64 select HAVE_PERF_EVENTS + select MMU_GATHER_RCU_TABLE_FREE # GENERIC_ALLOCATOR is used by dma_alloc_coherent() select GENERIC_ALLOCATOR select GENERIC_IRQ_PROBE diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 11835eb59d94..e29610fd1240 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -36,6 +36,7 @@ config M68K select HAVE_MOD_ARCH_SPECIFIC select HAVE_UID16 select MMU_GATHER_NO_RANGE if MMU + select MMU_GATHER_RCU_TABLE_FREE if MMU && SUN3 select MODULES_USE_ELF_REL select MODULES_USE_ELF_RELA select NO_DMA if !MMU && !COLDFIRE diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig index 9c0e6eaeb005..b0ccfc3b7a7e 100644 --- a/arch/nios2/Kconfig +++ b/arch/nios2/Kconfig @@ -19,6 +19,7 @@ config NIOS2 select HAVE_PAGE_SIZE_4KB select IRQ_DOMAIN select LOCK_MM_AND_FIND_VMA + select MMU_GATHER_RCU_TABLE_FREE select MODULES_USE_ELF_RELA select OF select OF_EARLY_FLATTREE diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig index 5eb995c13074..d90b24dd3bce 100644 --- a/arch/openrisc/Kconfig +++ b/arch/openrisc/Kconfig @@ -35,6 +35,7 @@ config OPENRISC select GENERIC_ATOMIC64 select GENERIC_CLOCKEVENTS_BROADCAST select GENERIC_SMP_IDLE_THREAD + select MMU_GATHER_RCU_TABLE_FREE select MODULES_USE_ELF_RELA select HAVE_DEBUG_STACKOVERFLOW select OR1K_PIC diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index d60f1d5a94c0..204f64912f0e 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -61,6 +61,7 @@ config SUPERH select HAVE_SYSCALL_TRACEPOINTS select IRQ_FORCED_THREADING select LOCK_MM_AND_FIND_VMA + select MMU_GATHER_RCU_TABLE_FREE if MMU && !X2TLB select MODULES_USE_ELF_RELA select NEED_SG_DMA_LENGTH select NO_DMA if !MMU && !DMA_COHERENT -- 2.55.0