For locality, always allocate one leaf_info with the leaf.
This method uses pointer arithmetic to identify this specially allocated
leaf_info to avoid freeing it.
It is possible to construct pathalogical cases where this ends up
wasting a leaf_info, ie. construct a route with two prefixes then always
delete the first.
Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
--- a/net/ipv4/fib_trie.c 2008-01-15 09:48:21.000000000 -0800
+++ b/net/ipv4/fib_trie.c 2008-01-15 09:49:39.000000000 -0800
@@ -326,8 +326,12 @@ static void __leaf_info_free_rcu(struct
kfree(container_of(head, struct leaf_info, rcu));
}
-static inline void free_leaf_info(struct leaf_info *leaf)
+static inline void free_leaf_info(struct leaf *l, struct leaf_info *leaf)
{
+ /* special case of cached leaf_info */
+ if (leaf == (struct leaf_info *)(l + 1))
+ return;
+
call_rcu(&leaf->rcu, __leaf_info_free_rcu);
}
@@ -376,13 +380,25 @@ static struct leaf *leaf_new(void)
return l;
}
+static void leaf_info_init(struct leaf_info *li, int plen)
+{
+ li->plen = plen;
+ INIT_LIST_HEAD(&li->falh);
+}
+
+static struct leaf_info *leaf_info_first(struct leaf *l, int plen)
+{
+ struct leaf_info *li = (struct leaf_info *) (l + 1);
+ leaf_info_init(li, plen);
+ return li;
+}
+
static struct leaf_info *leaf_info_new(int plen)
{
struct leaf_info *li = kmalloc(sizeof(struct leaf_info), GFP_KERNEL);
- if (li) {
- li->plen = plen;
- INIT_LIST_HEAD(&li->falh);
- }
+ if (li)
+ leaf_info_init(li, plen);
+
return li;
}
@@ -1046,18 +1062,13 @@ static struct list_head *fib_insert_node
insert_leaf_info(&l->list, li);
goto done;
}
- l = leaf_new();
+ l = leaf_new();
if (!l)
return NULL;
l->key = key;
- li = leaf_info_new(plen);
-
- if (!li) {
- tnode_free((struct tnode *) l);
- return NULL;
- }
+ li = leaf_info_first(l, plen);
fa_head = &li->falh;
insert_leaf_info(&l->list, li);
@@ -1090,7 +1101,7 @@ static struct list_head *fib_insert_node
}
if (!tn) {
- free_leaf_info(li);
+ free_leaf_info(l, li);
tnode_free((struct tnode *) l);
return NULL;
}
@@ -1622,7 +1633,7 @@ static int fn_trie_delete(struct fib_tab
if (list_empty(fa_head)) {
hlist_del_rcu(&li->hlist);
- free_leaf_info(li);
+ free_leaf_info(l, li);
}
if (hlist_empty(&l->list))
@@ -1666,7 +1677,7 @@ static int trie_flush_leaf(struct trie *
if (list_empty(&li->falh)) {
hlist_del_rcu(&li->hlist);
- free_leaf_info(li);
+ free_leaf_info(l, li);
}
}
return found;
@@ -1933,7 +1944,8 @@ void __init fib_hash_init(void)
fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct
fib_alias),
0, SLAB_PANIC, NULL);
- trie_leaf_kmem = kmem_cache_create("ip_fib_trie", sizeof(struct leaf),
+ trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
+ sizeof(struct leaf) + sizeof(struct
leaf_info),
0, SLAB_PANIC, NULL);
}
--
Stephen Hemminger <[EMAIL PROTECTED]>
--
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