[PATCH] mm/rmap: Move anon_vma initialization to anon_vma_ctor()

From: Ye Liu
Date: Tue Apr 15 2025 - 05:26:16 EST


From: Ye Liu <liuye@xxxxxxxxxx>

Currently, some initialization of anon_vma is performed in
anon_vma_alloc(). Move the initialization to anon_vma_ctor()
so that all object setup is handled in one place.

Signed-off-by: Ye Liu <liuye@xxxxxxxxxx>
---
mm/rmap.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index 67bb273dfb80..9802b1c27e4b 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -89,22 +89,7 @@ static struct kmem_cache *anon_vma_chain_cachep;

static inline struct anon_vma *anon_vma_alloc(void)
{
- struct anon_vma *anon_vma;
-
- anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);
- if (anon_vma) {
- atomic_set(&anon_vma->refcount, 1);
- anon_vma->num_children = 0;
- anon_vma->num_active_vmas = 0;
- anon_vma->parent = anon_vma;
- /*
- * Initialise the anon_vma root to point to itself. If called
- * from fork, the root will be reset to the parents anon_vma.
- */
- anon_vma->root = anon_vma;
- }
-
- return anon_vma;
+ return kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);
}

static inline void anon_vma_free(struct anon_vma *anon_vma)
@@ -453,8 +438,16 @@ static void anon_vma_ctor(void *data)
struct anon_vma *anon_vma = data;

init_rwsem(&anon_vma->rwsem);
- atomic_set(&anon_vma->refcount, 0);
+ atomic_set(&anon_vma->refcount, 1);
anon_vma->rb_root = RB_ROOT_CACHED;
+ anon_vma->num_children = 0;
+ anon_vma->num_active_vmas = 0;
+ anon_vma->parent = anon_vma;
+ /*
+ * Initialise the anon_vma root to point to itself. If called
+ * from fork, the root will be reset to the parents anon_vma.
+ */
+ anon_vma->root = anon_vma;
}

void __init anon_vma_init(void)
--
2.25.1