Commit 73848a97 authored Sep 23, 2019 by Wei Yang Committed by Linus Torvalds Sep 24, 2019

mm/mmap.c: refine find_vma_prev() with rb_last()

When addr is out of range of the whole rb_tree, pprev will point to the
right-most node.  rb_tree facility already provides a helper function,
rb_last(), to do this task.  We can leverage this instead of
reimplementing it.

This patch refines find_vma_prev() with rb_last() to make it a little
nicer to read.

[akpm@linux-foundation.org: little cleanup, per Vlastimil]
Link: http://lkml.kernel.org/r/20190809001928.4950-1-richardw.yang@linux.intel.com


Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 54c95a11

mm/mmap.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -2274,12 +2274,9 @@ find_vma_prev(struct mm_struct *mm, unsigned long addr,
		if (vma) {
		*pprev = vma->vm_prev;
		} else {
		struct rb_node *rb_node = mm->mm_rb.rb_node;
		*pprev = NULL;
		while (rb_node) {
		*pprev = rb_entry(rb_node, struct vm_area_struct, vm_rb);
		rb_node = rb_node->rb_right;
		}
		struct rb_node *rb_node = rb_last(&mm->mm_rb);

		*pprev = rb_node ? rb_entry(rb_node, struct vm_area_struct, vm_rb) : NULL;
		}
		return vma;
		}

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