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 1775F404BFD for ; Fri, 10 Jul 2026 22:46:30 +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=1783723591; cv=none; b=OVsrwFHGyyHgC/1b/40jfUkCrJm1ej8OqsXhBa8v0HOBRgMCC1i1+VknVGnnkAjWAAEwbRXeaoxMqv50hRzbgBfVT3R2bs+O1VUn8AKSetGT3D0LIFpJGjbTpaL6hWdQQuYkKJOJvhS4Ut05wRtwUekY+T9DSmsawEC+2JVDoOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783723591; c=relaxed/simple; bh=57k9N1pQOMSgoYfvi45CMjUjCOI+9lQOUKq93mSUUDc=; h=Date:To:From:Subject:Message-Id; b=NF73JsdEmHJEbQm/+yxs+U+XAqJI4eASQeOAOPckYema8sQpmMcDqyQD3bBY1s80aZaJLQbTE8tOkb6QiHW4rp1/QDr3v+JnKi6VCgxPFSiHz+uIT+GfqTukTrYHL68LFCKfmF/4TLgbr1B817jU5luiGhr7bx74EEi/bgzRaQY= 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=wOTYvNwT; 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="wOTYvNwT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D72D71F000E9; Fri, 10 Jul 2026 22:46:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1783723590; bh=TXhLH6n6sxenlkeQuNt9EN8wFXIbp+sVcMzHENES1/M=; h=Date:To:From:Subject; b=wOTYvNwTh/oHd4g7igfj5NQSqc5oamSKjvLUTyeBR5mWorp/vr0TD3QXBhbAyOk8K rB/SN9L1RchnObFneEbVwXLkQn+jej7Fe4b8EULOVjlMDkAIt2DbzLprj8lDeoFbXh PbgMfLfrShM4Dyh5LR75C5A+kYnq0rR8WAcWykxA= Date: Fri, 10 Jul 2026 15:46:29 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-vma-clean-up-anon_vma_compatible.patch added to mm-new branch Message-Id: <20260710224629.D72D71F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/vma: clean up anon_vma_compatible() has been added to the -mm mm-new branch. Its filename is mm-vma-clean-up-anon_vma_compatible.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vma-clean-up-anon_vma_compatible.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 Subject: mm/vma: clean up anon_vma_compatible() Date: Fri, 10 Jul 2026 21:16:55 +0100 Break up the existing very large conditional, add comments and use vma_[start/end]_pgoff() to make clearer what we're doing here. No functional change intended. Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-14-2a5aa403d977@kernel.org Signed-off-by: Lorenzo Stoakes Reviewed-by: Gregory Price Reviewed-by: Pedro Falcato Cc: Ackerley Tng Cc: David Hildenbrand (Arm) Cc: Kai Huang Cc: Marek Szyprowski Cc: SJ Park Cc: Thomas Zimmermann Cc: Vlastimil Babka (SUSE) Signed-off-by: Andrew Morton --- mm/vma.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) --- a/mm/vma.c~mm-vma-clean-up-anon_vma_compatible +++ a/mm/vma.c @@ -1967,14 +1967,25 @@ static int anon_vma_compatible(struct vm { vma_flags_t diff = vma_flags_diff_pair(&a->flags, &b->flags); + /* Ignore flags that mprotect() can change. */ vma_flags_clear_mask(&diff, VMA_ACCESS_FLAGS); + /* Ignore flags that do not impact merging. */ vma_flags_clear_mask(&diff, VMA_IGNORE_MERGE_FLAGS); - return a->vm_end == b->vm_start && - mpol_equal(vma_policy(a), vma_policy(b)) && - a->vm_file == b->vm_file && - vma_flags_empty(&diff) && - b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT); + /* Must be adjacent. */ + if (a->vm_end != b->vm_start) + return false; + /* Must have matching policy. */ + if (!mpol_equal(vma_policy(a), vma_policy(b))) + return false; + /* Must both be anon or map the same file (MAP_PRIVATE case). */ + if (a->vm_file != b->vm_file) + return false; + /* Flags must be equivalent modulo mprotect(). */ + if (!vma_flags_empty(&diff)) + return false; + /* Page offset must align. */ + return vma_end_pgoff(a) == vma_start_pgoff(b); } /* _ Patches currently in -mm which might be from ljs@kernel.org are mm-move-alloc-tag-to-mm.patch mm-ptdump-always-stabilise-against-page-table-freeing-using-init_mm.patch mm-vmalloc-acquire-init_mm-read-lock-on-huge-vmap-promotion.patch revert-arm64-enable-vmalloc-huge-with-ptdump.patch mm-move-vma_start_pgoff-into-mmh-and-clean-up.patch mm-add-kdoc-comments-for-vma_start-last_pgoff.patch tools-testing-vma-use-vma_start_pgoff-in-merge-tests.patch mm-introduce-and-use-vma_end_pgoff.patch mm-rmap-update-mm-interval_treec-comments.patch mm-rmap-parameterise-vma_interval_tree_-by-address_space.patch mm-rmap-elide-unnecessary-static-inlines-in-interval_treec.patch mm-rmap-rename-vma_interval_tree_-to-mapping_rmap_tree_.patch mm-rmap-parameterise-anon_vma_interval_tree_-by-anon_vma.patch mm-rmap-rename-anon_vma_interval_tree_-params-and-use-pgoff_t.patch mm-rmap-rename-anon_vma_interval_tree_-to-anon_rmap_tree_.patch maintainers-move-mm-interval_treec-to-rmap-section.patch mm-vma-introduce-and-use-vmg_pages-vmg__pgoff.patch mm-vma-clean-up-anon_vma_compatible.patch mm-vma-refactor-vmg_adjust_set_range-for-clarity.patch mm-vma-minor-cleanup-of-expand_.patch mm-introduce-and-use-linear_page_delta.patch mm-vma-use-vma_start_pgoff-linear_page_index-in-mm-code.patch mm-prefer-vma__pgoff-to-vma-vm_pgoff-in-kernel.patch mm-vma-remove-duplicative-vma_pgoff_offset-helper.patch mm-use-linear_page_-consistently.patch mm-vma-introduce-vma_assert_can_modify.patch mm-vma-add-and-use-vma__pgoff.patch mm-vma-move-__install_special_mapping-to-vmac.patch mm-vma-make-vma_set_range-static-drop-insert_vm_struct-decl.patch mm-vma-update-vma_shrink-to-not-pass-start-pgoff-parameters.patch mm-vma-update-vmg_adjust_set_range-to-offset-pgoff-instead.patch mm-vma-slightly-rework-the-anonymous-check-in-__mmap_new_vma.patch mm-vma-introduce-and-use-vma_set_pgoff.patch mm-vma-correct-incorrect-vmah-inclusion.patch mm-vma-use-guard-clauses-in-can_vma_merge_.patch tools-testing-vma-default-vma-mm-flag-bits-to-64-bit.patch tools-testing-vma-output-compared-expression-on-assert_.patch