[PATCH 3/3] tools/testing/radix-tree: Test maple tree chaining mas_preallocate() calls

From: Liam R. Howlett
Date: Mon Jun 16 2025 - 14:46:53 EST


Testing calling multiple mas_preallocate() calls in a row after
adjusting the maple state. Ensures new calls to mas_preallocate() will
change the number of allocated nodes.

Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
tools/testing/radix-tree/maple.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c
index 6a5b0342941c4..49e89dfad950c 100644
--- a/tools/testing/radix-tree/maple.c
+++ b/tools/testing/radix-tree/maple.c
@@ -35693,6 +35693,18 @@ static noinline void __init check_prealloc(struct maple_tree *mt)
allocated = mas_allocated(&mas);
height = mas_mt_height(&mas);
MT_BUG_ON(mt, allocated != 0);
+
+ /* Chaining multiple preallocations */
+ mt_set_in_rcu(mt);
+ mas_set_range(&mas, 800, 805); /* Slot store, should be 0 allocations */
+ MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
+ allocated = mas_allocated(&mas);
+ MT_BUG_ON(mt, allocated != 0);
+ mas.last = 809; /* Node store */
+ MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
+ allocated = mas_allocated(&mas);
+ MT_BUG_ON(mt, allocated != 1);
+ mas_store_prealloc(&mas, ptr);
}
/* End of preallocation testing */

--
2.47.2