Commit c465be97 authored Jan 20, 2023 by Liam R. Howlett Committed by Andrew Morton Feb 09, 2023

mm: remove unnecessary write to vma iterator in __vma_adjust()

If the vma start address is going to change due to an insert, then it is
safe to not write the vma to the tree.  The write of the insert vma will
alter the tree as necessary.

Link: https://lkml.kernel.org/r/20230120162650.984577-35-Liam.Howlett@oracle.com


Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 85ab779e

mm/mmap.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -719,10 +719,12 @@ int __vma_adjust(struct vma_iterator vmi, struct vm_area_struct vma,
		}

		if (start != vma->vm_start) {
		if ((vma->vm_start < start) &&
		(!insert \|\| (insert->vm_end != start))) {
		if (vma->vm_start < start) {
		if (!insert \|\| (insert->vm_end != start)) {
		vma_iter_clear(vmi, vma->vm_start, start);
		vma_iter_set(vmi, start);
		VM_WARN_ON(insert && insert->vm_start > vma->vm_start);
		}
		} else {
		vma_changed = true;
		}