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Commit 27e7190efd5b2f728686a8293af6d9bd34c4e562

Authored by Eric Dumazet
Committed by Pablo Neira Ayuso
1 parent 8892475386
Exists in smarc-imx_3.14.28_1.0.0_ga and in 1 other branch imx_3.14.28_1.0.0_ga

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 <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Showing 1 changed file with 6 additions and 4 deletions Side-by-side Diff

net/netfilter/xt_CT.c
Diff comments   View file @ 27e7190
... ... @@ -26,6 +26,9 @@
26 26 if (skb->nfct != NULL)
27 27 return XT_CONTINUE;
28 28  
  29 + /* special case the untracked ct : we want the percpu object */
  30 + if (!ct)
  31 + ct = nf_ct_untracked_get();
29 32 atomic_inc(&ct->ct_general.use);
30 33 skb->nfct = &ct->ct_general;
31 34 skb->nfctinfo = IP_CT_NEW;
... ... @@ -186,8 +189,7 @@
186 189 int ret = -EOPNOTSUPP;
187 190  
188 191 if (info->flags & XT_CT_NOTRACK) {
189   - ct = nf_ct_untracked_get();
190   - atomic_inc(&ct->ct_general.use);
  192 + ct = NULL;
191 193 goto out;
192 194 }
193 195  
... ... @@ -311,7 +313,7 @@
311 313 struct nf_conn *ct = info->ct;
312 314 struct nf_conn_help *help;
313 315  
314   - if (!nf_ct_is_untracked(ct)) {
  316 + if (ct && !nf_ct_is_untracked(ct)) {
315 317 help = nfct_help(ct);
316 318 if (help)
317 319 module_put(help->helper->me);
318 320  
... ... @@ -319,8 +321,8 @@
319 321 nf_ct_l3proto_module_put(par->family);
320 322  
321 323 xt_ct_destroy_timeout(ct);
  324 + nf_ct_put(info->ct);
322 325 }
323   - nf_ct_put(info->ct);
324 326 }
325 327  
326 328 static void xt_ct_tg_destroy_v0(const struct xt_tgdtor_param *par)