+ mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: move vma_mmu_pagesize() from hugetlb to vma.c
has been added to the -mm mm-new branch.  Its filename is
     mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac.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

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------------------------------------------------------
From: "David Hildenbrand (Arm)" <david@kernel.org>
Subject: mm: move vma_mmu_pagesize() from hugetlb to vma.c
Date: Mon, 9 Mar 2026 16:18:59 +0100

vma_mmu_pagesize() is also queried on non-hugetlb VMAs and does not really
belong into hugetlb.c.

PPC64 provides a custom overwrite with CONFIG_HUGETLB_PAGE, see
arch/powerpc/mm/book3s64/slice.c, so we cannot easily make this a static
inline function.

So let's move it to vma.c and add some proper kerneldoc.

To make vma tests happy, add a simple vma_kernel_pagesize() stub in
tools/testing/vma/include/custom.h.

Link: https://lkml.kernel.org/r/20260309151901.123947-3-david@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/hugetlb.h            |    7 -------
 include/linux/mm.h                 |    2 ++
 mm/hugetlb.c                       |   11 -----------
 mm/vma.c                           |   21 +++++++++++++++++++++
 tools/testing/vma/include/custom.h |    5 +++++
 5 files changed, 28 insertions(+), 18 deletions(-)

--- a/include/linux/hugetlb.h~mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac
+++ a/include/linux/hugetlb.h
@@ -777,8 +777,6 @@ static inline unsigned long huge_page_si
 	return (unsigned long)PAGE_SIZE << h->order;
 }
 
-extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
-
 static inline unsigned long huge_page_mask(struct hstate *h)
 {
 	return h->mask;
@@ -1186,11 +1184,6 @@ static inline unsigned long huge_page_ma
 	return PAGE_MASK;
 }
 
-static inline unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
-{
-	return PAGE_SIZE;
-}
-
 static inline unsigned int huge_page_order(struct hstate *h)
 {
 	return 0;
--- a/include/linux/mm.h~mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac
+++ a/include/linux/mm.h
@@ -1379,6 +1379,8 @@ static inline unsigned long vma_kernel_p
 	return PAGE_SIZE;
 }
 
+unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
+
 static inline
 struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max)
 {
--- a/mm/hugetlb.c~mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac
+++ a/mm/hugetlb.c
@@ -1007,17 +1007,6 @@ static long region_count(struct resv_map
 }
 
 /*
- * Return the page size being used by the MMU to back a VMA. In the majority
- * of cases, the page size used by the kernel matches the MMU size. On
- * architectures where it differs, an architecture-specific 'strong'
- * version of this symbol is required.
- */
-__weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
-{
-	return vma_kernel_pagesize(vma);
-}
-
-/*
  * Flags for MAP_PRIVATE reservations.  These are stored in the bottom
  * bits of the reservation map pointer, which are always clear due to
  * alignment.
--- a/mm/vma.c~mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac
+++ a/mm/vma.c
@@ -3300,3 +3300,24 @@ int insert_vm_struct(struct mm_struct *m
 
 	return 0;
 }
+
+/**
+ * vma_mmu_pagesize - Default MMU page size granularity for this VMA.
+ * @vma: The user mapping.
+ *
+ * In the common case, the default page size used by the MMU matches the
+ * default page size used by the kernel (see vma_kernel_pagesize()). On
+ * architectures where it differs, an architecture-specific 'strong' version
+ * of this symbol is required.
+ *
+ * The default MMU page size is not affected by Transparent Huge Pages
+ * being in effect, or any usage of larger MMU page sizes (either through
+ * architectural huge-page mappings or other explicit/implicit coalescing of
+ * virtual ranges performed by the MMU).
+ *
+ * Return: The default MMU page size granularity for this VMA.
+ */
+__weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
+{
+	return vma_kernel_pagesize(vma);
+}
--- a/tools/testing/vma/include/custom.h~mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac
+++ a/tools/testing/vma/include/custom.h
@@ -118,3 +118,8 @@ static __always_inline vma_flags_t __mk_
 			vma_flags_set_flag(&flags, bits[i]);
 	return flags;
 }
+
+static inline unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
+{
+	return PAGE_SIZE;
+}
_

Patches currently in -mm which might be from david@kernel.org are

mm-centralizefix-comments-about-compound_mapcount-in-new-sync_with_folio_pmd_zap.patch
mm-pagewalk-drop-fw_migration.patch
mm-madvise-drop-range-checks-in-madvise_free_single_vma.patch
mm-memory-remove-zap_details-parameter-from-zap_page_range_single.patch
mm-memory-remove-zap_details-parameter-from-zap_page_range_single-fix.patch
mm-memory-inline-unmap_mapping_range_vma-into-unmap_mapping_range_tree.patch
mm-memory-simplify-calculation-in-unmap_mapping_range_tree.patch
mm-oom_kill-use-mmu_notify_clear-in-__oom_reap_task_mm.patch
mm-oom_kill-factor-out-zapping-of-vma-into-zap_vma_for_reaping.patch
mm-memory-rename-unmap_single_vma-to-__zap_vma_range.patch
mm-memory-move-adjusting-of-address-range-to-unmap_vmas.patch
mm-memory-convert-details-even_cows-into-details-skip_cows.patch
mm-memory-use-__zap_vma_range-in-zap_vma_for_reaping.patch
mm-memory-inline-unmap_page_range-into-__zap_vma_range.patch
mm-rename-zap_vma_pages-to-zap_vma.patch
mm-rename-zap_page_range_single_batched-to-zap_vma_range_batched.patch
mm-rename-zap_page_range_single-to-zap_vma_range.patch
mm-rename-zap_vma_ptes-to-zap_special_vma_range.patch
mm-memory-support-vm_mixedmap-in-zap_special_vma_range.patch
kasan-docs-slub-is-the-only-remaining-slab-implementation.patch
mm-move-vma_kernel_pagesize-from-hugetlb-to-mmh.patch
mm-move-vma_mmu_pagesize-from-hugetlb-to-vmac.patch
kvm-remove-hugetlbh-inclusion.patch
kvm-ppc-remove-hugetlbh-inclusion.patch