diff --git a/tools/testing/radix-tree/linux.c b/tools/testing/radix-tree/linux.c
index 44a0d1ad4408..2d9c59df60de 100644
--- a/tools/testing/radix-tree/linux.c
+++ b/tools/testing/radix-tree/linux.c
@@ -19,37 +19,44 @@ int test_verbose;
 
 struct kmem_cache {
 	pthread_mutex_t lock;
-	int size;
+	unsigned int size;
+	unsigned int align;
 	int nr_objs;
 	void *objs;
 	void (*ctor)(void *);
 };
 
-void *kmem_cache_alloc(struct kmem_cache *cachep, int flags)
+void *kmem_cache_alloc(struct kmem_cache *cachep, int gfp)
 {
-	struct radix_tree_node *node;
+	void *p;
 
-	if (!(flags & __GFP_DIRECT_RECLAIM))
+	if (!(gfp & __GFP_DIRECT_RECLAIM))
 		return NULL;
 
 	pthread_mutex_lock(&cachep->lock);
 	if (cachep->nr_objs) {
+		struct radix_tree_node *node = cachep->objs;
 		cachep->nr_objs--;
-		node = cachep->objs;
 		cachep->objs = node->parent;
 		pthread_mutex_unlock(&cachep->lock);
 		node->parent = NULL;
+		p = node;
 	} else {
 		pthread_mutex_unlock(&cachep->lock);
-		node = malloc(cachep->size);
+		if (cachep->align)
+			posix_memalign(&p, cachep->align, cachep->size);
+		else
+			p = malloc(cachep->size);
 		if (cachep->ctor)
-			cachep->ctor(node);
+			cachep->ctor(p);
+		else if (gfp & __GFP_ZERO)
+			memset(p, 0, cachep->size);
 	}
 
 	uatomic_inc(&nr_allocated);
 	if (kmalloc_verbose)
-		printf("Allocating %p from slab\n", node);
-	return node;
+		printf("Allocating %p from slab\n", p);
+	return p;
 }
 
 void kmem_cache_free(struct kmem_cache *cachep, void *objp)
@@ -59,7 +66,7 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp)
 	if (kmalloc_verbose)
 		printf("Freeing %p to slab\n", objp);
 	pthread_mutex_lock(&cachep->lock);
-	if (cachep->nr_objs > 10) {
+	if (cachep->nr_objs > 10 || cachep->align) {
 		memset(objp, POISON_FREE, cachep->size);
 		free(objp);
 	} else {
@@ -98,13 +105,14 @@ void kfree(void *p)
 }
 
 struct kmem_cache *
-kmem_cache_create(const char *name, size_t size, size_t offset,
-	unsigned long flags, void (*ctor)(void *))
+kmem_cache_create(const char *name, unsigned int size, unsigned int align,
+		unsigned int flags, void (*ctor)(void *))
 {
 	struct kmem_cache *ret = malloc(sizeof(*ret));
 
 	pthread_mutex_init(&ret->lock, NULL);
 	ret->size = size;
+	ret->align = align;
 	ret->nr_objs = 0;
 	ret->objs = NULL;
 	ret->ctor = ctor;
diff --git a/tools/testing/radix-tree/linux/slab.h b/tools/testing/radix-tree/linux/slab.h
index a037def0dec6..2958830ce4d7 100644
--- a/tools/testing/radix-tree/linux/slab.h
+++ b/tools/testing/radix-tree/linux/slab.h
@@ -20,8 +20,8 @@ static inline void *kzalloc(size_t size, gfp_t gfp)
 void *kmem_cache_alloc(struct kmem_cache *cachep, int flags);
 void kmem_cache_free(struct kmem_cache *cachep, void *objp);
 
-struct kmem_cache *
-kmem_cache_create(const char *name, size_t size, size_t offset,
-	unsigned long flags, void (*ctor)(void *));
+struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
+			unsigned int align, unsigned int flags,
+			void (*ctor)(void *));
 
 #endif		/* SLAB_H */