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[NETFILTER]: nf_conntrack: optimize __nf_conntrack_find()

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Ignoring specific entries in __nf_conntrack_find() is only needed by NAT
for nf_conntrack_tuple_taken(). Remove it from __nf_conntrack_find()
and make nf_conntrack_tuple_taken() search the hash itself.

Saves 54 bytes of text in the hotpath on x86_64:

  __nf_conntrack_find      |  -54 # 321 -> 267, # inlines: 3 -> 2, size inlines: 181 -> 127
  nf_conntrack_tuple_taken | +305 # 15 -> 320, lexblocks: 0 -> 3, # inlines: 0 -> 3, size inlines: 0 -> 181
  nf_conntrack_find_get    |   -2 # 90 -> 88
 3 functions changed, 305 bytes added, 56 bytes removed, diff: +249

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2008-01-31 04:39:23 -08:00 committed by David S. Miller
parent f8ba1affa1
commit ba419aff2c
4 changed files with 20 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/net/netfilter/nf_conntrack.h
View File

@ -178,8 +178,7 @@ extern void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced,
unsigned int size);
extern struct nf_conntrack_tuple_hash *
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack);
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple);
extern void nf_conntrack_hash_insert(struct nf_conn *ct);

22
net/netfilter/nf_conntrack_core.c
View File

@ -246,16 +246,14 @@ static void death_by_timeout(unsigned long ul_conntrack)
}
struct nf_conntrack_tuple_hash *
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack)
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple)
{
struct nf_conntrack_tuple_hash *h;
struct hlist_node *n;
unsigned int hash = hash_conntrack(tuple);
hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
nf_ct_tuple_equal(tuple, &h->tuple)) {
if (nf_ct_tuple_equal(tuple, &h->tuple)) {
NF_CT_STAT_INC(found);
return h;
}
@ -274,7 +272,7 @@ nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple)
struct nf_conn *ct;
rcu_read_lock();
h = __nf_conntrack_find(tuple, NULL);
h = __nf_conntrack_find(tuple);
if (h) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
@ -395,12 +393,22 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack)
{
struct nf_conntrack_tuple_hash *h;
struct hlist_node *n;
unsigned int hash = hash_conntrack(tuple);
rcu_read_lock();
h = __nf_conntrack_find(tuple, ignored_conntrack);
hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) {
if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
nf_ct_tuple_equal(tuple, &h->tuple)) {
NF_CT_STAT_INC(found);
rcu_read_unlock();
return 1;
}
NF_CT_STAT_INC(searched);
}
rcu_read_unlock();
return h != NULL;
return 0;
}
EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);

6
net/netfilter/nf_conntrack_netlink.c
View File

@ -1222,9 +1222,9 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
spin_lock_bh(&nf_conntrack_lock);
if (cda[CTA_TUPLE_ORIG])
h = __nf_conntrack_find(&otuple, NULL);
h = __nf_conntrack_find(&otuple);
else if (cda[CTA_TUPLE_REPLY])
h = __nf_conntrack_find(&rtuple, NULL);
h = __nf_conntrack_find(&rtuple);
if (h == NULL) {
struct nf_conntrack_tuple master;
@ -1239,7 +1239,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
if (err < 0)
goto out_unlock;
master_h = __nf_conntrack_find(&master, NULL);
master_h = __nf_conntrack_find(&master);
if (master_h == NULL) {
err = -ENOENT;
goto out_unlock;

2
net/netfilter/xt_connlimit.c
View File

@ -124,7 +124,7 @@ static int count_them(struct xt_connlimit_data *data,
/* check the saved connections */
list_for_each_entry_safe(conn, tmp, hash, list) {
found = __nf_conntrack_find(&conn->tuple, NULL);
found = __nf_conntrack_find(&conn->tuple);
found_ct = NULL;
if (found != NULL)