maple_tree: goto complete directly on a pivot of 0

When we break the loop after assigning a pivot, the index i/j is not
changed.  Then the following code assign pivot, which means we do the
assignment with same i/j by mas_safe_pivot.

Since the loop condition is (i < piv_end), from which we can get i is less
than mt_pivots[mt].  It implies mas_safe_pivot() return pivot[i] which is
the same value we get in loop.

Now we can conclude it does a redundant assignment on a pivot of 0.  Let's
just go to complete to avoid it.

Link: https://lkml.kernel.org/r/20240911142759.20989-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 55958cbcc3fafba8620ac0e60a4461fa36a998cd..de883bfb97ef7b4df347fce19eb5cd36ccb3ae34 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1943,7 +1943,7 @@ static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start,
        for (; i < piv_end; i++, j++) {
                b_node->pivot[j] = pivots[i];
                if (unlikely(!b_node->pivot[j]))
-                       break;
+                       goto complete;
 
                if (unlikely(mas->max == b_node->pivot[j]))
                        goto complete;