From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 94411194137 for ; Fri, 25 Jul 2025 02:15:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753409732; cv=none; b=Snit0uAMG6a2YkzL+3hHvOnA9+CCBpZT0lGQLDnzKQeeFuoPMEK3pWde8L9kXQ9NqfnrCcjdKUo9X4GZK4o8TyNi2nJT4EjapYTIr0pZ/nYx6S5LcU85Ad0D/t1NLdilqjrcTf9p50nuQvp3v1ixh5AxLAr+nSBZWUVRCFOUoOE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753409732; c=relaxed/simple; bh=gsX5WcPx27anr0kKjglL0zEnq2RRTC13NPV6Uos68Lw=; h=Date:To:From:Subject:Message-Id; b=VQTAWe7OlZLreklKd9Bi1Dd1DqHuV3Iv5Km/1vur16DMiStH6ccIJjH5g+ddn8nojCk8a7vp8evoymIVG2NJ1dnAiwpkiduIgLlMB184IpAWpJgnzS9bVwaOkAMEBxIJcD9M2wy/GBkACIfogLgZE26W8lLlNjOOA4BFndvNc/o= 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=xEeF1Ufx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="xEeF1Ufx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 677B0C4CEED; Fri, 25 Jul 2025 02:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1753409732; bh=gsX5WcPx27anr0kKjglL0zEnq2RRTC13NPV6Uos68Lw=; h=Date:To:From:Subject:From; b=xEeF1UfxaDqTZPTvuNeOsFyPWidHwtaihxvfAXszf9s/ZjsY+4QhwMunNOWAeNBrB bc+7e9xnSVMh9rjPlIt7sjKIg+m2Z9yUvh92uB2e1Gg/HfvVLYgI9Z8U+iZjISOT6V 2G6TfgEhvFrkfxFXa/ArWWhxiXbZDaIBYF2eUVPQ= Date: Thu, 24 Jul 2025 19:15:31 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,yangyicong@hisilicon.com,yang@os.amperecomputing.com,willy@infradead.org,will@kernel.org,vbabka@suse.cz,ryan.roberts@arm.com,quic_zhenhuah@quicinc.com,peterx@redhat.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,kevin.brodsky@arm.com,joey.gouly@arm.com,jannh@google.com,ioworker0@gmail.com,hughd@google.com,david@redhat.com,christophe.leroy@csgroup.eu,catalin.marinas@arm.com,baohua@kernel.org,anshuman.khandual@arm.com,dev.jain@arm.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-add-batched-versions-of-ptep_modify_prot_start-commit.patch removed from -mm tree Message-Id: <20250725021532.677B0C4CEED@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: add batched versions of ptep_modify_prot_start/commit has been removed from the -mm tree. Its filename was mm-add-batched-versions-of-ptep_modify_prot_start-commit.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Dev Jain Subject: mm: add batched versions of ptep_modify_prot_start/commit Date: Fri, 18 Jul 2025 14:32:40 +0530 Batch ptep_modify_prot_start/commit in preparation for optimizing mprotect, implementing them as a simple loop over the corresponding single pte helpers. Architecture may override these helpers. Link: https://lkml.kernel.org/r/20250718090244.21092-4-dev.jain@arm.com Signed-off-by: Dev Jain Reviewed-by: Lorenzo Stoakes Reviewed-by: Barry Song Reviewed-by: Ryan Roberts Reviewed-by: Zi Yan Cc: Anshuman Khandual Cc: Catalin Marinas Cc: Christophe Leroy Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jann Horn Cc: Joey Gouly Cc: Kevin Brodsky Cc: Lance Yang Cc: Liam Howlett Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Vlastimil Babka Cc: Will Deacon Cc: Yang Shi Cc: Yicong Yang Cc: Zhenhua Huang Signed-off-by: Andrew Morton --- include/linux/pgtable.h | 84 +++++++++++++++++++++++++++++++++++++- mm/mprotect.c | 4 - 2 files changed, 85 insertions(+), 3 deletions(-) --- a/include/linux/pgtable.h~mm-add-batched-versions-of-ptep_modify_prot_start-commit +++ a/include/linux/pgtable.h @@ -1331,7 +1331,9 @@ static inline pte_t ptep_modify_prot_sta /* * Commit an update to a pte, leaving any hardware-controlled bits in - * the PTE unmodified. + * the PTE unmodified. The pte returned from ptep_modify_prot_start() may + * additionally have young and/or dirty bits set where previously they were not, + * so the updated pte may have these additional changes. */ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, @@ -1340,6 +1342,86 @@ static inline void ptep_modify_prot_comm __ptep_modify_prot_commit(vma, addr, ptep, pte); } #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ + +/** + * modify_prot_start_ptes - Start a pte protection read-modify-write transaction + * over a batch of ptes, which protects against asynchronous hardware + * modifications to the ptes. The intention is not to prevent the hardware from + * making pte updates, but to prevent any updates it may make from being lost. + * Please see the comment above ptep_modify_prot_start() for full description. + * + * @vma: The virtual memory area the pages are mapped into. + * @addr: Address the first page is mapped at. + * @ptep: Page table pointer for the first entry. + * @nr: Number of entries. + * + * May be overridden by the architecture; otherwise, implemented as a simple + * loop over ptep_modify_prot_start(), collecting the a/d bits from each pte + * in the batch. + * + * Note that PTE bits in the PTE batch besides the PFN can differ. + * + * Context: The caller holds the page table lock. The PTEs map consecutive + * pages that belong to the same folio. All other PTE bits must be identical for + * all PTEs in the batch except for young and dirty bits. The PTEs are all in + * the same PMD. + */ +#ifndef modify_prot_start_ptes +static inline pte_t modify_prot_start_ptes(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, unsigned int nr) +{ + pte_t pte, tmp_pte; + + pte = ptep_modify_prot_start(vma, addr, ptep); + while (--nr) { + ptep++; + addr += PAGE_SIZE; + tmp_pte = ptep_modify_prot_start(vma, addr, ptep); + if (pte_dirty(tmp_pte)) + pte = pte_mkdirty(pte); + if (pte_young(tmp_pte)) + pte = pte_mkyoung(pte); + } + return pte; +} +#endif + +/** + * modify_prot_commit_ptes - Commit an update to a batch of ptes, leaving any + * hardware-controlled bits in the PTE unmodified. + * + * @vma: The virtual memory area the pages are mapped into. + * @addr: Address the first page is mapped at. + * @ptep: Page table pointer for the first entry. + * @old_pte: Old page table entry (for the first entry) which is now cleared. + * @pte: New page table entry to be set. + * @nr: Number of entries. + * + * May be overridden by the architecture; otherwise, implemented as a simple + * loop over ptep_modify_prot_commit(). + * + * Context: The caller holds the page table lock. The PTEs are all in the same + * PMD. On exit, the set ptes in the batch map the same folio. The ptes set by + * ptep_modify_prot_start() may additionally have young and/or dirty bits set + * where previously they were not, so the updated ptes may have these + * additional changes. + */ +#ifndef modify_prot_commit_ptes +static inline void modify_prot_commit_ptes(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep, pte_t old_pte, pte_t pte, unsigned int nr) +{ + int i; + + for (i = 0; i < nr; ++i, ++ptep, addr += PAGE_SIZE) { + ptep_modify_prot_commit(vma, addr, ptep, old_pte, pte); + + /* Advance PFN only, set same prot */ + old_pte = pte_next_pfn(old_pte); + pte = pte_next_pfn(pte); + } +} +#endif + #endif /* CONFIG_MMU */ /* --- a/mm/mprotect.c~mm-add-batched-versions-of-ptep_modify_prot_start-commit +++ a/mm/mprotect.c @@ -204,7 +204,7 @@ static long change_pte_range(struct mmu_ } } - oldpte = ptep_modify_prot_start(vma, addr, pte); + oldpte = modify_prot_start_ptes(vma, addr, pte, nr_ptes); ptent = pte_modify(oldpte, newprot); if (uffd_wp) @@ -230,7 +230,7 @@ static long change_pte_range(struct mmu_ can_change_pte_writable(vma, addr, ptent)) ptent = pte_mkwrite(ptent, vma); - ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent); + modify_prot_commit_ptes(vma, addr, pte, oldpte, ptent, nr_ptes); if (pte_needs_flush(oldpte, ptent)) tlb_flush_pte_range(tlb, addr, PAGE_SIZE); pages++; _ Patches currently in -mm which might be from dev.jain@arm.com are khugepaged-optimize-__collapse_huge_page_copy_succeeded-by-pte-batching.patch khugepaged-optimize-collapse_pte_mapped_thp-by-pte-batching.patch