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 A7CF93C3F73 for ; Tue, 8 Sep 2026 21:16:21 +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=1788902183; cv=none; b=Qpoop5JQechhDT/QnorJ8E1d46gFDrAwrqZtfqd+TZJRP3yrCz01m0z0KIme/f67faQavy6jN2NvABy1H9AYSBi1iCKjWsN0O/SN1RxrTcoySwZy8OAPNRcfxcpFS8HHpgxl0GM5ezU+jy42+18rAsdvza+xkbkJbnM/6Pbh4ek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788902183; c=relaxed/simple; bh=AqD0KvcH8j4OmLJlJqIT2WO0ZcuUlZzPmsF+Z1y9m3I=; h=Date:To:From:Subject:Message-Id; b=Cu7uOVJPerjY2f2FXivgWZiWHZjyroNnTfH27X5nhHiuJS2Pw53ztj6vwHTtU6BL1Zg9SvYw2t0RjI4xYmSCCHjIacvPLcmnVQ7WKLM2t3d2E/ovJvDYoBVKAvWv98RAGR/TNZJTSdJOHiCF0c37NKmdsN3VkZTp6m+l1EBFkKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=s0tBF3RO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="s0tBF3RO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DAA01F00A3A; Tue, 8 Sep 2026 21:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788902181; bh=sZ8UBiIf9YtnIdZjoN11ZkYPS/IiCi3NTlI0V2WZuOE=; h=Date:To:From:Subject; b=s0tBF3RObWmmcbBNIdlKnJlWcymijAACaGMBzUcqE9RAysmewYnHtNgVSYX3wz150 WEHD8a3pKXum21fJ69ivaH6dDCtJF0S5OM38+tYJgZYIuH+wDOaZtVYi5Isy+AQe0Y ybcrS1CXJGVUw4dF6TdQBe5wvADWRhoxgofwetRM= Date: Tue, 08 Sep 2026 14:16:20 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv.patch added to mm-new branch Message-Id: <20260908211621.2DAA01F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: enable MMU_GATHER_RCU_TABLE_FREE for MMU riscv has been added to the -mm mm-new branch. Its filename is mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Lorenzo Stoakes (ARM)" Subject: mm: enable MMU_GATHER_RCU_TABLE_FREE for MMU riscv Date: Tue, 08 Sep 2026 13:32:12 +0100 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. Link: https://lore.kernel.org/20260908-rcu-pagetable-freeing-v2-3-1f60b64e878e@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Andreas Larsson Cc: "Aneesh Kumar K.V" Cc: Anton Ivanov Cc: Arnd Bergmann Cc: Baolin Wang Cc: Barry Song Cc: "Borislav Petkov (AMD)" Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Christian Zankel Cc: Dave Hansen Cc: David Hildenbrand Cc: David S. Miller Cc: Dev Jain Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Bottomley Cc: Jason Gunthorpe Cc: Johannes Berg Cc: John Hubbard Cc: John Paul Adrian Glaubitz Cc: Jonas Bonn Cc: Kiryl Shutsemau Cc: Lance Yang Cc: Liam R. Howlett Cc: Madhavan Srinivasan Cc: Magnus Lindholm Cc: Marc Rutland Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Simek Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Peter Xu Cc: Peter Zijlstra Cc: Richard Henderson Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Ryan Roberts Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: Vlastimil Babka Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Cc: Zi Yan Signed-off-by: Andrew Morton --- arch/riscv/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/riscv/Kconfig~mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv +++ a/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 _ Patches currently in -mm which might be from ljs@kernel.org are mm-vma-correctly-unaccount-on-mmap_prepare-failure.patch mm-vmpressure-remove-window-size-todo.patch tools-testing-selftests-mm-add-missing-gitignore-entries.patch mm-move-drivers-char-memc-to-mm-char-memc.patch mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero.patch mm-vma-only-permit-map_private-dev-zero-to-be-mapped-anonymous.patch mm-vma-make-map_private-mapped-dev-zero-mappings-truly-anonymous.patch tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.patch tools-testing-selftests-mm-add-map_private-dev-zero-merge-tests.patch mm-madvise-swap-in-cowd-map_private-file-mappings-on-madv_willneed.patch mm-huge_memory-zap-deposited-page-tables-after-an-rcu-grace-period.patch mm-enable-mmu_gather_rcu_table_free-for-most-2-level-architectures.patch mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv.patch mm-enable-mmu_gather_rcu_table_free-for-mmu-arm.patch mm-enable-mmu_gather_rcu_table_free-for-arc-microblaze-xtensa.patch mm-enable-mmu_gather_rcu_table_free-for-sparc64.patch mm-enable-mmu_gather_rcu_table_free-for-m68k-coldfire.patch mm-enable-mmu_gather_rcu_table_free-for-sh-x2.patch mm-enable-mmu_gather_rcu_table_free-for-m68k-motorola.patch mm-enable-mmu_gather_rcu_table_free-for-sparc32.patch mm-make-userland-page-table-freeing-rcu-safe.patch mm-change-the-contract-for-free_pgtables-update-docs.patch