Commit 9ce7bc03 authored by Eric Dumazet's avatar Eric Dumazet Committed by Pablo Neira Ayuso
Browse files

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: c038a767 ("ipv6: add a new namespace for nf_conntrack_reasm")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent ba062ebb

include/net/net_namespace.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

include/net/netns/ipv6.h

+0 −1
Original line number Diff line number Diff line
@@ -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

net/ipv6/netfilter/nf_conntrack_reasm.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

}

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