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authorWei Yang <richardw.yang@linux.intel.com>2019-09-24 01:39:25 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-25 01:54:12 +0300
commit73848a9711105836346462e1d3c6b5765b452de1 (patch)
tree1b564f7f54f5990bdbe3e84ebcf1324a9915e9d6
parent54c95a11cc1b5e1d578209e027adf5775395dafd (diff)
downloadlinux-73848a9711105836346462e1d3c6b5765b452de1.tar.xz
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>
-rw-r--r--mm/mmap.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 6bc21fca20bc..e4a8f67aad62 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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;
}