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 9FFE8366055 for ; Wed, 16 Sep 2026 02:06:41 +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=1789524410; cv=none; b=fk9hvzqi8aUBAaszwW8FB0vPaloOkYiZOrbHgPJe96giCgFlYznvp+fiNEKhM0F4bUzQ7cW9flgYknpqP6iJ7EwAF3Ps4NlDIAlG1FQ5NmCrN3fvUlIk2tWq/cDV8pVKst0crsiw+a2twCbVbLAZUZw9HDEcy4kdyPzyuDKqw24= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789524410; c=relaxed/simple; bh=mhq49/KZlFDZNyQHAfvRgaibDQ9APo/E3prxjGrFvQ4=; h=Date:To:From:Subject:Message-Id; b=D/Rou3mvkuvSM0IvleVN+IXpHYwUMK4hTkEX5tbvNmuHga/iovmDjxgxLs6azwvJZ9ClxhN0MK7+Lkmu4NcJNKmmby9YGfCgFMduZGIgkMRAuDlBt4zSYegRxGTfGXbilbe55+p21LrUJbhL8DzNTJBsgxI32eLaLoTtRMgbSk8= 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=Bwivnlgs; 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="Bwivnlgs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3745C1F000FF; Wed, 16 Sep 2026 02:06:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789524399; bh=VbMdJM0n+VJDzo+4Yx91Qwsax0tts7QE5gA8nqHAJv4=; h=Date:To:From:Subject; b=BwivnlgsRpxv/jdBE9qR8oWwLLKm6R9Gq8KkhsP+hi3204rp9rJFkQYaC/zpKRKhj awWa622C1xVdUst3U+wtDvp2Cxh4Y2YlLQA/+rpkHJIvgnTsbAPEzF1/TTaH+8DefI RU2mWdDKaOpIevxuTtL2zoRQtMSvQfG6mV8tcCvQ= Date: Tue, 15 Sep 2026 19:06:38 -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-sh-x2.patch added to mm-unstable branch Message-Id: <20260916020639.3745C1F000FF@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 sh-X2 has been added to the -mm mm-unstable branch. Its filename is mm-enable-mmu_gather_rcu_table_free-for-sh-x2.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-sh-x2.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 sh-X2 Date: Fri, 11 Sep 2026 20:36:55 +0100 Currently, non-x2 sh specifies CONFIG_MMU_GATHER_RCU_TABLE_FREE allowing RCU page table freeing. sh-X2 is problematic because it utilises slab-allocated PMD page tables, and thus tlb_remove_ptdesc() cannot be used in these cases. All other sh variants are fine as commit e3ecf7c7d082 ("mm: pgtable: convert some architectures to use tlb_remove_ptdesc()") already converted page table freeing to use tlb_remove_ptdesc(), which does so after an RCU grace period when CONFIG_MMU_GATHER_RCU_TABLE_FREE is specified. Resolve this issue by firstly specifying CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE for sh-X2, so the arch can provide its own __tlb_remove_table() implementation (called after the RCU grace period). Then, convert __pmd_free_tlb() to tag the pointer to the PMD, and have __tlb_remove_table() check this tag to determine whether to free via the slab or to use pagetable_dtor_free(). This follows the pattern used by sparc64 as implemented in commit 4a0100f7546f ("sparc64: use RCU page table freeing"). Previously __pmd_free_tlb() freed PMD page tables immediately, before any TLB flush IPI. This seems to be a pre-existing bug, which this change also resolves. CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE is only specified for sh-X2, as setting it disables CONFIG_PT_RECLAIM and causes __tlb_remove_table_one() to call tlb_remove_table_sync_rcu() and synchronize_rcu() in turn, and this is not necessary for other sh variants. This forms part of an overall effort to switch every architecture to this mode. Link: https://lore.kernel.org/20260911-rcu-pagetable-freeing-v3-8-7b8c86103821@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Andrew Morton Acked-by: Kiryl Shutsemau (Meta) 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: 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 --- arch/sh/Kconfig | 3 ++- arch/sh/include/asm/pgalloc.h | 6 +++++- arch/sh/mm/pgtable.c | 20 ++++++++++++++++++++ 3 files changed, 27 insertions(+), 2 deletions(-) --- a/arch/sh/include/asm/pgalloc.h~mm-enable-mmu_gather_rcu_table_free-for-sh-x2 +++ a/arch/sh/include/asm/pgalloc.h @@ -17,7 +17,11 @@ extern void pgd_free(struct mm_struct *m extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd); extern pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address); extern void pmd_free(struct mm_struct *mm, pmd_t *pmd); -#define __pmd_free_tlb(tlb, pmdp, addr) pmd_free((tlb)->mm, (pmdp)) +extern void __tlb_remove_table(void *table); + +/* PMDs are slab-allocated, tag so they are freed correctly. */ +#define __pmd_free_tlb(tlb, pmdp, addr) \ + tlb_remove_table((tlb), (void *)((unsigned long)(pmdp) | 1)) #endif static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, --- a/arch/sh/Kconfig~mm-enable-mmu_gather_rcu_table_free-for-sh-x2 +++ a/arch/sh/Kconfig @@ -33,6 +33,7 @@ config SUPERH select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_KGDB select HAVE_ARCH_SECCOMP_FILTER + select HAVE_ARCH_TLB_REMOVE_TABLE if X2TLB select HAVE_ARCH_TRACEHOOK select HAVE_DEBUG_BUGVERBOSE select HAVE_DEBUG_KMEMLEAK @@ -61,7 +62,7 @@ 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 MMU_GATHER_RCU_TABLE_FREE if MMU select MODULES_USE_ELF_RELA select NEED_SG_DMA_LENGTH select NO_DMA if !MMU && !DMA_COHERENT --- a/arch/sh/mm/pgtable.c~mm-enable-mmu_gather_rcu_table_free-for-sh-x2 +++ a/arch/sh/mm/pgtable.c @@ -56,4 +56,24 @@ void pmd_free(struct mm_struct *mm, pmd_ { kmem_cache_free(pmd_cachep, pmd); } + +static void __tlb_remove_table_slab(void *table) +{ + kmem_cache_free(pmd_cachep, table); +} + +static void __tlb_remove_table_pgtable(void *table) +{ + pagetable_dtor_free(table); +} + +void __tlb_remove_table(void *table) +{ + const unsigned long addr = (unsigned long)table; + + if (addr & 1) + __tlb_remove_table_slab((void *)(addr & ~1UL)); + else + __tlb_remove_table_pgtable(table); +} #endif /* PAGETABLE_LEVELS > 2 */ _ Patches currently in -mm which might be from ljs@kernel.org are 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 mm-vma-fix-mmap_prepare-file-handling-remove-file_doesnt_need_get.patch mm-vma-predicate-setting-mmap_prepare-vma-fields-on-new-vma-alloc.patch mm-vma-introduce-and-use-vma_can_merge.patch mm-consistently-validate-vma-state-after-mmap-hooks.patch mm-vma-ensure-mmap_prepare-doesnt-set-actions-on-a-mergeable-vma.patch mm-make-map_kernel_pages_-internal-and-unexported.patch mm-vma-tidy-up-map-kernel-pages-enum-values.patch mm-add-mmap-action-for-discontiguous-kernel-page-mapping.patch docs-filesystems-update-mmap_prepare-docs-for-discontig-kernel-pgs.patch drivers-usb-mon-update-to-use-mmap_prepare-map-kernel-pages.patch infiniband-update-hfi1-to-use-remap_vmalloc_range.patch selinux-reject-writable-opens-of-policy-file-drop-mmap-shared-write-check.patch alsa-pcm-use-vm_insert_page-to-map-pcm-status-page.patch bpf-arena-mark-arena_map_mmap-mappings-vm_mixedmap.patch mm-vma-add-vma_is_kernel_owned-predicates.patch mm-vma-only-allow-mmap-to-clear-vma_maywrite_bit-if-kernel-owned.patch mm-vma-add-and-use-vma__is_fixed_mapping.patch scsi-sg-convert-mmap-hook-to-mmap_prepare-and-rework.patch fbdev-defio-assert-fbinfo_virtfb-drop-vm_io-add-vm_mixedmap.patch hsi-cmt_speech-convert-mmap-hook-to-mmap_prepare-refactor.patch mm-gup-error-out-early-on-vma_mayread_bit-vmas.patch uprobes-remove-vm_io-set-vm_mixedmap-for-mapped-kernel-pages.patch mm-mlock-clear-vma_locked_mask-over-mmap-callback.patch mm-mlock-eliminate-weird-vma_io_bit-abuse-and-simplify.patch mm-vma-enforce-that-only-kernel-owned-mappings-may-set-vma_io_bit.patch mm-remove-vma_io_bit-check-in-vma_is_kernel_owned.patch mm-remove-hugetlb_inlineh.patch mm-rename-is_vm_hugetlb_page-to-vma_is_hugetlb.patch mm-drop-some-redundant-checks-around-hugetlb-vmas.patch mm-madvise-update-is_valid_guard_vma-to-use-vma_can_merge.patch mm-vma-introduce-vma_is_persistent.patch mm-uffd-use-predicates-for-userfaultfd-checks.patch mm-madvise-use-predicates-for-madvise-madv_dofork.patch mm-eliminate-vma_special_flags-usage-when-hugetlb-explicitly-tested.patch mm-eliminate-vma_special_flags-check-in-lru_gen_look_around.patch mm-avoid-use-of-vma_special_flags-in-migrate_vma_setup.patch mm-eliminate-vm_special-vma_special_flags.patch fuse-dax-do-not-set-vm_mixedmap.patch mm-huge_memory-remove-vma_is_special_huge.patch mm-vma-introduce-and-use-vma_can_gup.patch