+ mm-pagewalk-add-walk_page_range_vma.patch added to mm-unstable branch

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

The patch titled
     Subject: mm/pagewalk: add walk_page_range_vma()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-pagewalk-add-walk_page_range_vma.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-pagewalk-add-walk_page_range_vma.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
Subject: mm/pagewalk: add walk_page_range_vma()
Date: Fri, 30 Sep 2022 16:19:29 +0200

Let's add walk_page_range_vma(), which is similar to walk_page_vma(),
however, is only interested in a subset of the VMA range.

To be used in KSM code to stop using follow_page() next.

Link: https://lkml.kernel.org/r/20220930141931.174362-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/pagewalk.h |    3 +++
 mm/pagewalk.c            |   27 +++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

--- a/include/linux/pagewalk.h~mm-pagewalk-add-walk_page_range_vma
+++ a/include/linux/pagewalk.h
@@ -99,6 +99,9 @@ int walk_page_range_novma(struct mm_stru
 			  unsigned long end, const struct mm_walk_ops *ops,
 			  pgd_t *pgd,
 			  void *private);
+int walk_page_range_vma(struct vm_area_struct *vma, unsigned long start,
+			unsigned long end, const struct mm_walk_ops *ops,
+			void *private);
 int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
 		void *private);
 int walk_page_mapping(struct address_space *mapping, pgoff_t first_index,
--- a/mm/pagewalk.c~mm-pagewalk-add-walk_page_range_vma
+++ a/mm/pagewalk.c
@@ -517,6 +517,33 @@ int walk_page_range_novma(struct mm_stru
 	return walk_pgd_range(start, end, &walk);
 }
 
+int walk_page_range_vma(struct vm_area_struct *vma, unsigned long start,
+			unsigned long end, const struct mm_walk_ops *ops,
+			void *private)
+{
+	struct mm_walk walk = {
+		.ops		= ops,
+		.mm		= vma->vm_mm,
+		.vma		= vma,
+		.private	= private,
+	};
+	int err;
+
+	if (start >= end || !walk.mm)
+		return -EINVAL;
+	if (start < vma->vm_start || end > vma->vm_end)
+		return -EINVAL;
+
+	mmap_assert_locked(walk.mm);
+
+	err = walk_page_test(start, end, &walk);
+	if (err > 0)
+		return 0;
+	if (err < 0)
+		return err;
+	return __walk_page_range(start, end, &walk);
+}
+
 int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
 		void *private)
 {
_

Patches currently in -mm which might be from david@redhat.com are

selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch
mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch
mm-remove-vm_fault_write.patch
mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch
mm-pagewalk-add-walk_page_range_vma.patch
mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch
mm-gup-remove-foll_migration.patch