| Message ID | 20180613171156.240889-1-edumazet@google.com |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | [net] netfilter: ipv6: nf_defrag: reduce struct net memory waste | expand |
On Wed, Jun 13, 2018 at 10:11:56AM -0700, Eric Dumazet wrote: > 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. Also applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 47e35cce3b648d696b127ed7bd643036128795f6..a71264d75d7f98d28f92dfd861ffe6e0d39c0198 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -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; diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index c978a31b0f846210b4c2a369af960d5349b5395a..762ac9931b6251152b6ee0e5780df0f7b073f3e6 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -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 diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 5e0332014c1738999e680c1853829f384e880284..a452d99c9f5281b5e5d7e6f0162611deeb82212d 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -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); }
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> --- 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(-)