CONNTRACK_LOCKS is 1024 and power of 2, so modulo operations
can be replaced with AND (CONNTRACK_LOCKS - 1)
and bitwise AND operation is quicker than module operation
Signed-off-by: Zhang Yu <zhangyu31@xxxxxxxxx>
Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
---
include/net/netfilter/nf_conntrack_core.h | 4 +++-
net/netfilter/nf_conntrack_core.c | 10 +++++-----
net/netfilter/nf_conntrack_netlink.c | 2 +-
net/netfilter/nf_nat_core.c | 6 +++---
4 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index ae41e92251dd..1b75a141c63d 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -67,7 +67,9 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb)
void print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_l4proto *proto);
-#define CONNTRACK_LOCKS 1024
+#define CONNTRACK_LOCKS_BIT 10
+#define CONNTRACK_LOCKS (1 << CONNTRACK_LOCKS_BIT)
+#define CONNTRACK_LOCKS_MASK (CONNTRACK_LOCKS - 1)
extern spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
void nf_conntrack_lock(spinlock_t *lock);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index e139c256e269..a0feb530ed00 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -116,8 +116,8 @@ EXPORT_SYMBOL_GPL(nf_conntrack_lock);
static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
{
- h1 %= CONNTRACK_LOCKS;
- h2 %= CONNTRACK_LOCKS;
+ h1 &= CONNTRACK_LOCKS_MASK;
+ h2 &= CONNTRACK_LOCKS_MASK;
spin_unlock(&nf_conntrack_locks[h1]);
if (h1 != h2)
spin_unlock(&nf_conntrack_locks[h2]);
@@ -127,8 +127,8 @@ static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
unsigned int h2, unsigned int sequence)
{
- h1 %= CONNTRACK_LOCKS;
- h2 %= CONNTRACK_LOCKS;
+ h1 &= CONNTRACK_LOCKS_MASK;
+ h2 &= CONNTRACK_LOCKS_MASK;
if (h1 <= h2) {
nf_conntrack_lock(&nf_conntrack_locks[h1]);
if (h1 != h2)
@@ -1971,7 +1971,7 @@ get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
spinlock_t *lockp;
for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
- lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
+ lockp = &nf_conntrack_locks[*bucket & CONNTRACK_LOCKS_MASK];
local_bh_disable();
nf_conntrack_lock(lockp);
if (*bucket < nf_conntrack_htable_size) {
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 349b42a65c8a..8f22743c270f 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -918,7 +918,7 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
nf_ct_put(nf_ct_evict[i]);
}
- lockp = &nf_conntrack_locks[cb->args[0] % CONNTRACK_LOCKS];
+ lockp = &nf_conntrack_locks[cb->args[0] & CONNTRACK_LOCKS_MASK];
nf_conntrack_lock(lockp);
if (cb->args[0] >= nf_conntrack_htable_size) {
spin_unlock(lockp);
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 35e61038ae96..2b1d377bf3ab 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -588,7 +588,7 @@ nf_nat_setup_info(struct nf_conn *ct,
srchash = hash_by_src(net,
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
- lock = &nf_nat_locks[srchash % CONNTRACK_LOCKS];
+ lock = &nf_nat_locks[srchash & CONNTRACK_LOCKS_MASK];
spin_lock_bh(lock);
hlist_add_head_rcu(&ct->nat_bysource,
&nf_nat_bysource[srchash]);
@@ -773,9 +773,9 @@ static void __nf_nat_cleanup_conntrack(struct nf_conn *ct)
unsigned int h;
h = hash_by_src(nf_ct_net(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
- spin_lock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
+ spin_lock_bh(&nf_nat_locks[h & CONNTRACK_LOCKS_MASK]);
hlist_del_rcu(&ct->nat_bysource);
- spin_unlock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
+ spin_unlock_bh(&nf_nat_locks[h & CONNTRACK_LOCKS_MASK]);
}
static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
--
2.16.2
