| From foo@baz Wed Aug 22 09:42:09 CEST 2018 |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Wed, 13 Jun 2018 10:11:56 -0700 |
| Subject: netfilter: ipv6: nf_defrag: reduce struct net memory waste |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ Upstream commit 9ce7bc036ae4cfe3393232c86e9e1fea2153c237 ] |
| |
| 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: c038a767cd69 ("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> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| include/net/net_namespace.h | 1 + |
| include/net/netns/ipv6.h | 1 - |
| net/ipv6/netfilter/nf_conntrack_reasm.c | 6 +++--- |
| 3 files changed, 4 insertions(+), 4 deletions(-) |
| |
| --- a/include/net/net_namespace.h |
| +++ b/include/net/net_namespace.h |
| @@ -116,6 +116,7 @@ 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; |
| --- a/include/net/netns/ipv6.h |
| +++ b/include/net/netns/ipv6.h |
| @@ -89,7 +89,6 @@ struct netns_ipv6 { |
| |
| #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) |
| struct netns_nf_frag { |
| - struct netns_sysctl_ipv6 sysctl; |
| struct netns_frags frags; |
| }; |
| #endif |
| --- a/net/ipv6/netfilter/nf_conntrack_reasm.c |
| +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c |
| @@ -117,7 +117,7 @@ static int nf_ct_frag6_sysctl_register(s |
| if (hdr == NULL) |
| goto err_reg; |
| |
| - net->nf_frag.sysctl.frags_hdr = hdr; |
| + net->nf_frag_frags_hdr = hdr; |
| return 0; |
| |
| err_reg: |
| @@ -131,8 +131,8 @@ static void __net_exit nf_ct_frags6_sysc |
| { |
| 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); |
| } |