+ mm-use-vma_iter_clear_gfp-in-nommu.patch added to mm-unstable branch

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

The patch titled
     Subject: mm: use vma_iter_clear_gfp() in nommu
has been added to the -mm mm-unstable branch.  Its filename is
     mm-use-vma_iter_clear_gfp-in-nommu.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-use-vma_iter_clear_gfp-in-nommu.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: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Subject: mm: use vma_iter_clear_gfp() in nommu
Date: Wed, 31 May 2023 22:16:00 -0400

Move the definition of vma_iter_clear_gfp() from mmap.c to internal.h so
it can be used in the nommu code.  This will reduce node preallocations in
nommu.

Link: https://lkml.kernel.org/r/20230601021605.2823123-10-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/internal.h |   12 ++++++++++++
 mm/mmap.c     |   12 ------------
 mm/nommu.c    |   12 ++++--------
 3 files changed, 16 insertions(+), 20 deletions(-)

--- a/mm/internal.h~mm-use-vma_iter_clear_gfp-in-nommu
+++ a/mm/internal.h
@@ -1057,6 +1057,18 @@ static inline void vma_iter_clear(struct
 	mas_store_prealloc(&vmi->mas, NULL);
 }
 
+static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,
+			unsigned long start, unsigned long end, gfp_t gfp)
+{
+	vmi->mas.index = start;
+	vmi->mas.last = end - 1;
+	mas_store_gfp(&vmi->mas, NULL, gfp);
+	if (unlikely(mas_is_err(&vmi->mas)))
+		return -ENOMEM;
+
+	return 0;
+}
+
 static inline struct vm_area_struct *vma_iter_load(struct vma_iterator *vmi)
 {
 	return mas_walk(&vmi->mas);
--- a/mm/mmap.c~mm-use-vma_iter_clear_gfp-in-nommu
+++ a/mm/mmap.c
@@ -154,18 +154,6 @@ static inline struct vm_area_struct *vma
 	return mas_prev(&vmi->mas, min);
 }
 
-static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,
-			unsigned long start, unsigned long end, gfp_t gfp)
-{
-	vmi->mas.index = start;
-	vmi->mas.last = end - 1;
-	mas_store_gfp(&vmi->mas, NULL, gfp);
-	if (unlikely(mas_is_err(&vmi->mas)))
-		return -ENOMEM;
-
-	return 0;
-}
-
 /*
  * check_brk_limits() - Use platform specific check of range & verify mlock
  * limits.
--- a/mm/nommu.c~mm-use-vma_iter_clear_gfp-in-nommu
+++ a/mm/nommu.c
@@ -1383,17 +1383,13 @@ static int vmi_shrink_vma(struct vma_ite
 
 	/* adjust the VMA's pointers, which may reposition it in the MM's tree
 	 * and list */
-	if (vma_iter_prealloc(vmi)) {
-		pr_warn("Allocation of vma tree for process %d failed\n",
-		       current->pid);
-		return -ENOMEM;
-	}
-
 	if (from > vma->vm_start) {
-		vma_iter_clear(vmi, from, vma->vm_end);
+		if (vma_iter_clear_gfp(vmi, from, vma->vm_end, GFP_KERNEL))
+			return -ENOMEM;
 		vma->vm_end = from;
 	} else {
-		vma_iter_clear(vmi, vma->vm_start, to);
+		if (vma_iter_clear_gfp(vmi, vma->vm_start, to, GFP_KERNEL))
+			return -ENOMEM;
 		vma->vm_start = to;
 	}
 
_

Patches currently in -mm which might be from Liam.Howlett@oracle.com are

maple_tree-fix-static-analyser-cppcheck-issue.patch
maple_tree-avoid-unnecessary-ascending.patch
maple_tree-clean-up-mas_dfs_postorder.patch
maple_tree-add-debug-bug_on-and-warn_on-variants.patch
maple_tree-use-mas_bug_on-when-setting-a-leaf-node-as-a-parent.patch
maple_tree-use-mas_bug_on-in-mas_set_height.patch
maple_tree-use-mas_bug_on-from-mas_topiary_range.patch
maple_tree-use-mas_wr_bug_on-in-mas_store_prealloc.patch
maple_tree-use-mas_bug_on-prior-to-calling-mas_meta_gap.patch
maple_tree-return-error-on-mte_pivots-out-of-range.patch
maple_tree-make-test-code-work-without-debug-enabled.patch
mm-update-validate_mm-to-use-vma-iterator.patch
mm-update-vma_iter_store-to-use-mas_warn_on.patch
maple_tree-add-__init-and-__exit-to-test-module.patch
maple_tree-remove-unnecessary-check-from-mas_destroy.patch
maple_tree-mas_start-reset-depth-on-dead-node.patch
mm-mmap-change-do_vmi_align_munmap-for-maple-tree-iterator-changes.patch
maple_tree-try-harder-to-keep-active-node-after-mas_next.patch
maple_tree-try-harder-to-keep-active-node-with-mas_prev.patch
maple_tree-revise-limit-checks-in-mas_empty_area_rev.patch
maple_tree-fix-testing-mas_empty_area.patch
maple_tree-introduce-mas_next_slot-interface.patch
maple_tree-add-mas_next_range-and-mas_find_range-interfaces.patch
maple_tree-relocate-mas_rewalk-and-mas_rewalk_if_dead.patch
maple_tree-introduce-mas_prev_slot-interface.patch
maple_tree-add-mas_prev_range-and-mas_find_range_rev-interface.patch
maple_tree-clear-up-index-and-last-setting-in-single-entry-tree.patch
maple_tree-update-testing-code-for-mas_nextprevwalk.patch
mm-add-vma_iter_nextprev_range-to-vma-iterator.patch
mm-avoid-rewalk-in-mmap_region.patch
maple_tree-add-benchmarking-for-mas_for_each.patch
maple_tree-add-benchmarking-for-mas_prev.patch
mm-move-unmap_vmas-declaration-to-internal-header.patch
mm-change-do_vmi_align_munmap-side-tree-index.patch
mm-remove-prev-check-from-do_vmi_align_munmap.patch
maple_tree-introduce-__mas_set_range.patch
mm-remove-re-walk-from-mmap_region.patch
maple_tree-re-introduce-entry-to-mas_preallocate-arguments.patch
mm-use-vma_iter_clear_gfp-in-nommu.patch
mm-set-up-vma-iterator-for-vma_iter_prealloc-calls.patch
maple_tree-move-mas_wr_end_piv-below-mas_wr_extend_null.patch
maple_tree-update-mas_preallocate-testing.patch
maple_tree-refine-mas_preallocate-node-calculations.patch
mm-mmap-change-vma-iteration-order-in-do_vmi_align_munmap.patch