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fib_trie: move leaf and tnode to occupy the same spot in the key vector

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If we are going to compact the leaf and tnode we first need to make sure
the fields are all in the same place.  In that regard I am moving the leaf
pointer which represents the fib_alias hash list to occupy what is
currently the first key_vector pointer.

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 2015-03-04 15:02:33 -08:00 committed by David S. Miller
parent d5d6487cb8
commit 41b489fd6c
1 changed files with 29 additions and 26 deletions
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55
net/ipv4/fib_trie.c
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@ -94,24 +94,27 @@ typedef unsigned int t_key;
#define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> (_kv)->pos)
struct tnode {
t_key key;
unsigned char bits; /* 2log(KEYLENGTH) bits needed */
unsigned char pos; /* 2log(KEYLENGTH) bits needed */
unsigned char slen;
struct tnode __rcu *parent;
struct rcu_head rcu;
t_key empty_children; /* KEYLENGTH bits needed */
t_key full_children; /* KEYLENGTH bits needed */
struct tnode __rcu *parent;
t_key key;
unsigned char pos; /* 2log(KEYLENGTH) bits needed */
unsigned char bits; /* 2log(KEYLENGTH) bits needed */
unsigned char slen;
union {
/* The fields in this struct are valid if bits > 0 (TNODE) */
struct {
t_key empty_children; /* KEYLENGTH bits needed */
t_key full_children; /* KEYLENGTH bits needed */
struct tnode __rcu *child[0];
};
/* This list pointer if valid if bits == 0 (LEAF) */
/* This list pointer if valid if (pos | bits) == 0 (LEAF) */
struct hlist_head leaf;
/* This array is valid if (pos | bits) > 0 (TNODE) */
struct tnode __rcu *tnode[0];
};
};
#define TNODE_SIZE(n) offsetof(struct tnode, tnode[n])
#define LEAF_SIZE TNODE_SIZE(1)
#ifdef CONFIG_IP_FIB_TRIE_STATS
struct trie_use_stats {
unsigned int gets;
@ -180,14 +183,14 @@ static inline unsigned long tnode_child_length(const struct tnode *tn)
static inline struct tnode *tnode_get_child(const struct tnode *tn,
unsigned long i)
{
return rtnl_dereference(tn->child[i]);
return rtnl_dereference(tn->tnode[i]);
}
/* caller must hold RCU read lock or RTNL */
static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn,
unsigned long i)
{
return rcu_dereference_rtnl(tn->child[i]);
return rcu_dereference_rtnl(tn->tnode[i]);
}
/* To understand this stuff, an understanding of keys and all their bits is
@ -266,7 +269,7 @@ static inline void alias_free_mem_rcu(struct fib_alias *fa)
}
#define TNODE_KMALLOC_MAX \
ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct tnode *))
ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct tnode *))
static void __node_free_rcu(struct rcu_head *head)
{
@ -324,7 +327,7 @@ static struct tnode *leaf_new(t_key key, struct fib_alias *fa)
static struct tnode *tnode_new(t_key key, int pos, int bits)
{
size_t sz = offsetof(struct tnode, child[1ul << bits]);
size_t sz = TNODE_SIZE(1ul << bits);
struct tnode *tn = tnode_alloc(sz);
unsigned int shift = pos + bits;
@ -343,7 +346,7 @@ static struct tnode *tnode_new(t_key key, int pos, int bits)
tn->empty_children = 1ul << bits;
}
pr_debug("AT %p s=%zu %zu\n", tn, sizeof(struct tnode),
pr_debug("AT %p s=%zu %zu\n", tn, TNODE_SIZE(0),
sizeof(struct tnode *) << bits);
return tn;
}
@ -384,7 +387,7 @@ static void put_child(struct tnode *tn, unsigned long i, struct tnode *n)
if (n && (tn->slen < n->slen))
tn->slen = n->slen;
rcu_assign_pointer(tn->child[i], n);
rcu_assign_pointer(tn->tnode[i], n);
}
static void update_children(struct tnode *tn)
@ -435,7 +438,7 @@ static void tnode_free(struct tnode *tn)
while (head) {
head = head->next;
tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
tnode_free_size += TNODE_SIZE(1ul << tn->bits);
node_free(tn);
tn = container_of(head, struct tnode, rcu);
@ -788,7 +791,7 @@ static void resize(struct trie *t, struct tnode *tn)
* doing it ourselves. This way we can let RCU fully do its
* thing without us interfering
*/
cptr = tp ? &tp->child[get_index(tn->key, tp)] : &t->trie;
cptr = tp ? &tp->tnode[get_index(tn->key, tp)] : &t->trie;
BUG_ON(tn != rtnl_dereference(*cptr));
/* Double as long as the resulting node has a number of
@ -1241,7 +1244,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
/* Step 2: Sort out leaves and begin backtracing for longest prefix */
for (;;) {
/* record the pointer where our next node pointer is stored */
struct tnode __rcu **cptr = n->child;
struct tnode __rcu **cptr = n->tnode;
/* This test verifies that none of the bits that differ
* between the key and the prefix exist in the region of
@ -1287,7 +1290,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
cindex &= cindex - 1;
/* grab pointer for next child node */
cptr = &pn->child[cindex];
cptr = &pn->tnode[cindex];
}
}
@ -1685,7 +1688,7 @@ void __init fib_trie_init(void)
0, SLAB_PANIC, NULL);
trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
sizeof(struct tnode),
LEAF_SIZE,
0, SLAB_PANIC, NULL);
}
@ -1843,13 +1846,13 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
bytes = sizeof(struct tnode) * stat->leaves;
bytes = LEAF_SIZE * stat->leaves;
seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
bytes += sizeof(struct fib_alias) * stat->prefixes;
seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
bytes += sizeof(struct tnode) * stat->tnodes;
bytes += TNODE_SIZE(0) * stat->tnodes;
max = MAX_STAT_DEPTH;
while (max > 0 && stat->nodesizes[max-1] == 0)
@ -1918,7 +1921,7 @@ static int fib_triestat_seq_show(struct seq_file *seq, void *v)
seq_printf(seq,
"Basic info: size of leaf:"
" %Zd bytes, size of tnode: %Zd bytes.\n",
sizeof(struct tnode), sizeof(struct tnode));
LEAF_SIZE, TNODE_SIZE(0));
for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
struct hlist_head *head = &net->ipv4.fib_table_hash[h];