From dc35dbeda3e00a05723784078a233c2531d34810 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Fri, 6 Mar 2015 09:54:27 -0800 Subject: [PATCH] fib_trie: Add tnode struct as a container for fields not needed in key_vector This change pulls the fields not explicitly needed in the key_vector and placed them in the new tnode structure. By doing this we will eventually be able to reduce the key_vector down to 16 bytes on 64 bit systems, and 12 bytes on 32 bit systems. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ipv4/fib_trie.c | 72 ++++++++++++++++++++++++--------------------- 1 file changed, 39 insertions(+), 33 deletions(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index b88c0d0f48ed..3a062370fc32 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -111,7 +111,11 @@ struct key_vector { }; }; -#define TNODE_SIZE(n) offsetof(struct key_vector, tnode[n]) +struct tnode { + struct key_vector kv[1]; +}; + +#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) #define LEAF_SIZE TNODE_SIZE(1) #ifdef CONFIG_IP_FIB_TRIE_STATS @@ -288,7 +292,7 @@ static void __node_free_rcu(struct rcu_head *head) #define node_free(n) call_rcu(&n->rcu, __node_free_rcu) -static struct key_vector *tnode_alloc(int bits) +static struct tnode *tnode_alloc(int bits) { size_t size; @@ -317,48 +321,50 @@ static inline void empty_child_dec(struct key_vector *n) static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) { - struct key_vector *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); - if (l) { - l->parent = NULL; - /* set key and pos to reflect full key value - * any trailing zeros in the key should be ignored - * as the nodes are searched - */ - l->key = key; - l->slen = fa->fa_slen; - l->pos = 0; - /* set bits to 0 indicating we are not a tnode */ - l->bits = 0; - - /* link leaf to fib alias */ - INIT_HLIST_HEAD(&l->leaf); - hlist_add_head(&fa->fa_list, &l->leaf); - } + struct tnode *kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); + struct key_vector *l = kv->kv; + + if (!kv) + return NULL; + + /* initialize key vector */ + l->key = key; + l->pos = 0; + l->bits = 0; + l->slen = fa->fa_slen; + + /* link leaf to fib alias */ + INIT_HLIST_HEAD(&l->leaf); + hlist_add_head(&fa->fa_list, &l->leaf); + return l; } static struct key_vector *tnode_new(t_key key, int pos, int bits) { - struct key_vector *tn = tnode_alloc(bits); + struct tnode *tnode = tnode_alloc(bits); unsigned int shift = pos + bits; + struct key_vector *tn = tnode->kv; /* verify bits and pos their msb bits clear and values are valid */ BUG_ON(!bits || (shift > KEYLENGTH)); - if (tn) { - tn->parent = NULL; - tn->slen = pos; - tn->pos = pos; - tn->bits = bits; - tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; - if (bits == KEYLENGTH) - tn->full_children = 1; - else - tn->empty_children = 1ul << bits; - } - - pr_debug("AT %p s=%zu %zu\n", tn, TNODE_SIZE(0), + pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), sizeof(struct key_vector *) << bits); + + if (!tnode) + return NULL; + + if (bits == KEYLENGTH) + tn->full_children = 1; + else + tn->empty_children = 1ul << bits; + + tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; + tn->pos = pos; + tn->bits = bits; + tn->slen = pos; + return tn; } -- 2.34.1