From 27e7190efd5b2f728686a8293af6d9bd34c4e562 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 22 May 2013 11:10:57 +0000 Subject: [PATCH] netfilter: xt_CT: optimize XT_CT_NOTRACK The percpu untracked ct are not currently used for XT_CT_NOTRACK. xt_ct_tg_check()/xt_ct_target() provides a single ct. Thats not optimal as the ct->ct_general.use cache line will bounce among cpus. Use the intended [1] thing : xt_ct_target() should select the percpu object. [1] Refs : commit 5bfddbd46a95c97 ("netfilter: nf_conntrack: IPS_UNTRACKED bit") commit b3c5163fe0193a7 ("netfilter: nf_conntrack: per_cpu untracking") Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_CT.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c index a60261c..da35ac0 100644 --- a/net/netfilter/xt_CT.c +++ b/net/netfilter/xt_CT.c @@ -26,6 +26,9 @@ static inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct) if (skb->nfct != NULL) return XT_CONTINUE; + /* special case the untracked ct : we want the percpu object */ + if (!ct) + ct = nf_ct_untracked_get(); atomic_inc(&ct->ct_general.use); skb->nfct = &ct->ct_general; skb->nfctinfo = IP_CT_NEW; @@ -186,8 +189,7 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par, int ret = -EOPNOTSUPP; if (info->flags & XT_CT_NOTRACK) { - ct = nf_ct_untracked_get(); - atomic_inc(&ct->ct_general.use); + ct = NULL; goto out; } @@ -311,7 +313,7 @@ static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par, struct nf_conn *ct = info->ct; struct nf_conn_help *help; - if (!nf_ct_is_untracked(ct)) { + if (ct && !nf_ct_is_untracked(ct)) { help = nfct_help(ct); if (help) module_put(help->helper->me); @@ -319,8 +321,8 @@ static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par, nf_ct_l3proto_module_put(par->family); xt_ct_destroy_timeout(ct); + nf_ct_put(info->ct); } - nf_ct_put(info->ct); } static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par) -- 2.7.4