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fib_trie: Merge tnode_free and leaf_free into node_free

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Both the leaf and the tnode had an rcu_head in them, but they had them in
slightly different places.  Since we now have them in the same spot and
know that any node with bits == 0 is a leaf and the rest are either vmalloc
or kmalloc tnodes depending on the value of bits it makes it easy to combine
the functions and reduce overhead.

In addition I have taken advantage of the rcu_head pointer to go ahead and
put together a simple linked list instead of using the tnode pointer as
this way we can merge either type of structure for freeing.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Duyck 2014-12-31 10:55:41 -08:00 committed by David S. Miller
parent 64c9b6fb26
commit 37fd30f2da
1 changed files with 40 additions and 50 deletions
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90
net/ipv4/fib_trie.c
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@ -95,15 +95,17 @@ struct tnode {
unsigned char bits; /* 2log(KEYLENGTH) bits needed */
unsigned char pos; /* 2log(KEYLENGTH) bits needed */
struct tnode __rcu *parent;
union {
struct rcu_head rcu;
struct tnode *tnode_free;
};
struct rcu_head rcu;
/* everything above this comment must be the same as rt_trie_node */
unsigned int full_children; /* KEYLENGTH bits needed */
unsigned int empty_children; /* KEYLENGTH bits needed */
struct rt_trie_node __rcu *child[0];
};
/* This struct represents the shared bits between tnode and leaf. If any
* ordering is changed here is must also be updated in tnode and leaf as
* well.
*/
struct rt_trie_node {
t_key key;
unsigned char bits;
@ -118,6 +120,7 @@ struct leaf {
unsigned char pos;
struct tnode __rcu *parent;
struct rcu_head rcu;
/* everything above this comment must be the same as rt_trie_node */
struct hlist_head list;
};
@ -163,7 +166,7 @@ static struct rt_trie_node *resize(struct trie *t, struct tnode *tn);
static struct tnode *inflate(struct trie *t, struct tnode *tn);
static struct tnode *halve(struct trie *t, struct tnode *tn);
/* tnodes to free after resize(); protected by RTNL */
static struct tnode *tnode_free_head;
static struct callback_head *tnode_free_head;
static size_t tnode_free_size;
/*
@ -336,16 +339,22 @@ static inline void alias_free_mem_rcu(struct fib_alias *fa)
call_rcu(&fa->rcu, __alias_free_mem);
}
static void __leaf_free_rcu(struct rcu_head *head)
#define TNODE_KMALLOC_MAX \
ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct rt_trie_node *))
static void __node_free_rcu(struct rcu_head *head)
{
struct leaf *l = container_of(head, struct leaf, rcu);
kmem_cache_free(trie_leaf_kmem, l);
struct rt_trie_node *n = container_of(head, struct rt_trie_node, rcu);
if (IS_LEAF(n))
kmem_cache_free(trie_leaf_kmem, n);
else if (n->bits <= TNODE_KMALLOC_MAX)
kfree(n);
else
vfree(n);
}
static inline void free_leaf(struct leaf *l)
{
call_rcu(&l->rcu, __leaf_free_rcu);
}
#define node_free(n) call_rcu(&n->rcu, __node_free_rcu)
static inline void free_leaf_info(struct leaf_info *leaf)
{
@ -360,43 +369,24 @@ static struct tnode *tnode_alloc(size_t size)
return vzalloc(size);
}
static void __tnode_free_rcu(struct rcu_head *head)
{
struct tnode *tn = container_of(head, struct tnode, rcu);
size_t size = sizeof(struct tnode) +
(sizeof(struct rt_trie_node *) << tn->bits);
if (size <= PAGE_SIZE)
kfree(tn);
else
vfree(tn);
}
static inline void tnode_free(struct tnode *tn)
{
if (IS_LEAF(tn))
free_leaf((struct leaf *) tn);
else
call_rcu(&tn->rcu, __tnode_free_rcu);
}
static void tnode_free_safe(struct tnode *tn)
{
BUG_ON(IS_LEAF(tn));
tn->tnode_free = tnode_free_head;
tnode_free_head = tn;
tnode_free_size += sizeof(struct tnode) +
(sizeof(struct rt_trie_node *) << tn->bits);
tn->rcu.next = tnode_free_head;
tnode_free_head = &tn->rcu;
}
static void tnode_free_flush(void)
{
struct tnode *tn;
struct callback_head *head;
while ((tn = tnode_free_head)) {
tnode_free_head = tn->tnode_free;
tn->tnode_free = NULL;
tnode_free(tn);
while ((head = tnode_free_head)) {
struct tnode *tn = container_of(head, struct tnode, rcu);
tnode_free_head = head->next;
tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
node_free(tn);
}
if (tnode_free_size >= PAGE_SIZE * sync_pages) {
@ -437,7 +427,7 @@ static struct leaf_info *leaf_info_new(int plen)
static struct tnode *tnode_new(t_key key, int pos, int bits)
{
size_t sz = sizeof(struct tnode) + (sizeof(struct rt_trie_node *) << bits);
size_t sz = offsetof(struct tnode, child[1 << bits]);
struct tnode *tn = tnode_alloc(sz);
unsigned int shift = pos + bits;
@ -666,15 +656,15 @@ no_children:
static void tnode_clean_free(struct tnode *tn)
{
struct rt_trie_node *tofree;
int i;
struct tnode *tofree;
for (i = 0; i < tnode_child_length(tn); i++) {
tofree = (struct tnode *)rtnl_dereference(tn->child[i]);
tofree = rtnl_dereference(tn->child[i]);
if (tofree)
tnode_free(tofree);
node_free(tofree);
}
tnode_free(tn);
node_free(tn);
}
static struct tnode *inflate(struct trie *t, struct tnode *tn)
@ -717,7 +707,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn)
inode->bits - 1);
if (!right) {
tnode_free(left);
node_free(left);
goto nomem;
}
@ -1068,7 +1058,7 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
li = leaf_info_new(plen);
if (!li) {
free_leaf(l);
node_free(l);
return NULL;
}
@ -1100,7 +1090,7 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
if (!tn) {
free_leaf_info(li);
free_leaf(l);
node_free(l);
return NULL;
}
@ -1580,7 +1570,7 @@ static void trie_leaf_remove(struct trie *t, struct leaf *l)
} else
RCU_INIT_POINTER(t->trie, NULL);
free_leaf(l);
node_free(l);
}
/*