Re: [PATCH 03/11] maple_tree: Add some helper functions

From: Peng Zhang
Date: Mon Jul 31 2023 - 07:40:29 EST




在 2023/7/26 23:02, Liam R. Howlett 写道:
* Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx> [230726 04:10]:
Add some helper functions so that their parameters are maple node
instead of maple enode, these functions will be used later.

Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
---
lib/maple_tree.c | 71 +++++++++++++++++++++++++++++++++++++-----------
1 file changed, 55 insertions(+), 16 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index e0e9a87bdb43..da3a2fb405c0 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -164,6 +164,11 @@ static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes)
return kmem_cache_alloc_bulk(maple_node_cache, gfp, size, nodes);
}
+static inline void mt_free_one(struct maple_node *node)
+{
+ kmem_cache_free(maple_node_cache, node);
+}
+

There is a place in mas_destroy() that could use this if it is added.
I will make changes accordingly. It's not done here because it doesn't
seem to be relevant to the theme of this patchset.

static inline void mt_free_bulk(size_t size, void __rcu **nodes)
{
kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes);
@@ -432,18 +437,18 @@ static inline unsigned long mte_parent_slot_mask(unsigned long parent)
}
/*
- * mas_parent_type() - Return the maple_type of the parent from the stored
- * parent type.
- * @mas: The maple state
- * @enode: The maple_enode to extract the parent's enum
+ * ma_parent_type() - Return the maple_type of the parent from the stored parent
+ * type.
+ * @mt: The maple tree
+ * @node: The maple_node to extract the parent's enum
* Return: The node->parent maple_type
*/
static inline
-enum maple_type mas_parent_type(struct ma_state *mas, struct maple_enode *enode)
+enum maple_type ma_parent_type(struct maple_tree *mt, struct maple_node *node)

I was trying to keep ma_* prefix to mean the first argument is
maple_node and mt_* to mean maple_tree. I wasn't entirely successful
with this and I do see why you want to use ma_, but maybe reverse the
arguments here?
I just think it is redundant to construct maple enode through
node->parent in order to adapt the parameters of mte_*. So ma_* are
introduced to avoid meaningless construction.


{
unsigned long p_type;
- p_type = (unsigned long)mte_to_node(enode)->parent;
+ p_type = (unsigned long)node->parent;
if (WARN_ON(p_type & MAPLE_PARENT_ROOT))
return 0;
@@ -451,7 +456,7 @@ enum maple_type mas_parent_type(struct ma_state *mas, struct maple_enode *enode)
p_type &= ~mte_parent_slot_mask(p_type);
switch (p_type) {
case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */
- if (mt_is_alloc(mas->tree))
+ if (mt_is_alloc(mt))
return maple_arange_64;
return maple_range_64;
}
@@ -459,6 +464,19 @@ enum maple_type mas_parent_type(struct ma_state *mas, struct maple_enode *enode)
return 0;
}
+/*
+ * mas_parent_type() - Return the maple_type of the parent from the stored
+ * parent type.
+ * @mas: The maple state
+ * @enode: The maple_enode to extract the parent's enum
+ * Return: The node->parent maple_type
+ */
+static inline
+enum maple_type mas_parent_type(struct ma_state *mas, struct maple_enode *enode)
+{
+ return ma_parent_type(mas->tree, mte_to_node(enode));
+}
+
/*
* mas_set_parent() - Set the parent node and encode the slot
* @enode: The encoded maple node.
@@ -499,14 +517,14 @@ void mas_set_parent(struct ma_state *mas, struct maple_enode *enode,
}
/*
- * mte_parent_slot() - get the parent slot of @enode.
- * @enode: The encoded maple node.
+ * ma_parent_slot() - get the parent slot of @node.
+ * @node: The maple node.
*
- * Return: The slot in the parent node where @enode resides.
+ * Return: The slot in the parent node where @node resides.
*/
-static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
+static inline unsigned int ma_parent_slot(const struct maple_node *node)
{
- unsigned long val = (unsigned long)mte_to_node(enode)->parent;
+ unsigned long val = (unsigned long)node->parent;
if (val & MA_ROOT_PARENT)
return 0;
@@ -519,15 +537,36 @@ static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
}
/*
- * mte_parent() - Get the parent of @node.
- * @node: The encoded maple node.
+ * mte_parent_slot() - get the parent slot of @enode.
+ * @enode: The encoded maple node.
+ *
+ * Return: The slot in the parent node where @enode resides.
+ */
+static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
+{
+ return ma_parent_slot(mte_to_node(enode));
+}
+
+/*
+ * ma_parent() - Get the parent of @node.
+ * @node: The maple node.
+ *
+ * Return: The parent maple node.
+ */
+static inline struct maple_node *ma_parent(const struct maple_node *node)

I had a lot of these helpers before, but they eventually became used so
little that I dropped them.
Just for not wanting to construct maple enode. It's not really a
problem.

+{
+ return (void *)((unsigned long)(node->parent) & ~MAPLE_NODE_MASK);
+}
+
+/*
+ * mte_parent() - Get the parent of @enode.
+ * @enode: The encoded maple node.
*
* Return: The parent maple node.
*/
static inline struct maple_node *mte_parent(const struct maple_enode *enode)
{
- return (void *)((unsigned long)
- (mte_to_node(enode)->parent) & ~MAPLE_NODE_MASK);
+ return ma_parent(mte_to_node(enode));
}
/*
--
2.20.1