netfilter: ipv6: nf_defrag: reduce struct net memory waste

It is a waste of memory to use a full "struct netns_sysctl_ipv6"
while only one pointer is really used, considering netns_sysctl_ipv6
keeps growing.

Also, since "struct netns_frags" has cache line alignment,
it is better to move the frags_hdr pointer outside, otherwise
we spend a full cache line for this pointer.

This saves 192 bytes of memory per netns.

Fixes: c038a767cd ("ipv6: add a new namespace for nf_conntrack_reasm")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Eric Dumazet 2018-06-13 10:11:56 -07:00 committed by Pablo Neira Ayuso
parent ba062ebb2c
commit 9ce7bc036a
3 changed files with 4 additions and 4 deletions

View File

@ -128,6 +128,7 @@ struct net {
#endif
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
struct netns_nf_frag nf_frag;
struct ctl_table_header *nf_frag_frags_hdr;
#endif
struct sock *nfnl;
struct sock *nfnl_stash;

View File

@ -109,7 +109,6 @@ struct netns_ipv6 {
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
struct netns_nf_frag {
struct netns_sysctl_ipv6 sysctl;
struct netns_frags frags;
};
#endif

View File

@ -107,7 +107,7 @@ static int nf_ct_frag6_sysctl_register(struct net *net)
if (hdr == NULL)
goto err_reg;
net->nf_frag.sysctl.frags_hdr = hdr;
net->nf_frag_frags_hdr = hdr;
return 0;
err_reg:
@ -121,8 +121,8 @@ static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
{
struct ctl_table *table;
table = net->nf_frag.sysctl.frags_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->nf_frag.sysctl.frags_hdr);
table = net->nf_frag_frags_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->nf_frag_frags_hdr);
if (!net_eq(net, &init_net))
kfree(table);
}