netfilter: nf_conntrack: per_cpu untracking

NOTRACK makes all cpus share a cache line on nf_conntrack_untracked
twice per packet, slowing down performance.

This patch converts it to a per_cpu variable.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Eric Dumazet 2010-06-09 14:43:38 +02:00 committed by Patrick McHardy
parent 5bfddbd46a
commit b3c5163fe0
2 changed files with 28 additions and 13 deletions

View file

@ -261,11 +261,10 @@ extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
u32 seq);
/* Fake conntrack entry for untracked connections */
DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
static inline struct nf_conn *nf_ct_untracked_get(void)
{
extern struct nf_conn nf_conntrack_untracked;
return &nf_conntrack_untracked;
return &__raw_get_cpu_var(nf_conntrack_untracked);
}
extern void nf_ct_untracked_status_or(unsigned long bits);

View file

@ -62,8 +62,8 @@ EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
unsigned int nf_conntrack_max __read_mostly;
EXPORT_SYMBOL_GPL(nf_conntrack_max);
struct nf_conn nf_conntrack_untracked;
EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
static int nf_conntrack_hash_rnd_initted;
static unsigned int nf_conntrack_hash_rnd;
@ -1183,10 +1183,21 @@ static void nf_ct_release_dying_list(struct net *net)
spin_unlock_bh(&nf_conntrack_lock);
}
static int untrack_refs(void)
{
int cnt = 0, cpu;
for_each_possible_cpu(cpu) {
struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
cnt += atomic_read(&ct->ct_general.use) - 1;
}
return cnt;
}
static void nf_conntrack_cleanup_init_net(void)
{
/* wait until all references to nf_conntrack_untracked are dropped */
while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
while (untrack_refs() > 0)
schedule();
nf_conntrack_helper_fini();
@ -1323,14 +1334,17 @@ module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
void nf_ct_untracked_status_or(unsigned long bits)
{
nf_conntrack_untracked.status |= bits;
int cpu;
for_each_possible_cpu(cpu)
per_cpu(nf_conntrack_untracked, cpu).status |= bits;
}
EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
static int nf_conntrack_init_init_net(void)
{
int max_factor = 8;
int ret;
int ret, cpu;
/* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
* machine has 512 buckets. >= 1GB machines have 16384 buckets. */
@ -1369,10 +1383,12 @@ static int nf_conntrack_init_init_net(void)
goto err_extend;
#endif
/* Set up fake conntrack: to never be deleted, not in any hashes */
#ifdef CONFIG_NET_NS
nf_conntrack_untracked.ct_net = &init_net;
#endif
atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
for_each_possible_cpu(cpu) {
struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
write_pnet(&ct->ct_net, &init_net);
atomic_set(&ct->ct_general.use, 1);
}
/* - and look it like as a confirmed connection */
nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
return 0;