Commit 8cf4d6a2 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Pablo Neira Ayuso
Browse files

net: reorder struct netns_ct for better cache-line usage 

Reorder struct netns_ct so that atomic_t "count" changes don't
slowdown users of read mostly fields.

This is based on Eric Dumazet's proposed patch:
 "netfilter: conntrack: remove the central spinlock"
 http://thread.gmane.org/gmane.linux.network/268758/focus=47306



The tricky part of cache-aligning this structure, that it is getting
inlined in struct net (include/net/net_namespace.h), thus changes to
other netns_xxx structures affects our alignment.

Eric's original patch contained an ambiguity on 32-bit regarding
alignment in struct net.  This patch also takes 32-bit into account,
and in case of changed (struct net) alignment sysctl_xxx entries have
been ordered according to how often they are accessed.

Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: default avatarJiri Benc <jbenc@redhat.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 68536053

include/net/netns/conntrack.h

+17 −16
Original line number Diff line number Diff line
@@ -65,6 +65,23 @@ struct nf_ip_net { 
struct netns_ct {

	atomic_t		count;

	unsigned int		expect_count;

#ifdef CONFIG_SYSCTL

	struct ctl_table_header	*sysctl_header;

	struct ctl_table_header	*acct_sysctl_header;

	struct ctl_table_header	*tstamp_sysctl_header;

	struct ctl_table_header	*event_sysctl_header;

	struct ctl_table_header	*helper_sysctl_header;

#endif

	char			*slabname;

	unsigned int		sysctl_log_invalid; /* Log invalid packets */

	unsigned int		sysctl_events_retry_timeout;

	int			sysctl_events;

	int			sysctl_acct;

	int			sysctl_auto_assign_helper;

	bool			auto_assign_helper_warned;

	int			sysctl_tstamp;

	int			sysctl_checksum;



	unsigned int		htable_size;

	struct kmem_cache	*nf_conntrack_cachep;

	struct hlist_nulls_head	*hash;
@@ -75,14 +92,6 @@ struct netns_ct { 
	struct ip_conntrack_stat __percpu *stat;

	struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb;

	struct nf_exp_event_notifier __rcu *nf_expect_event_cb;

	int			sysctl_events;

	unsigned int		sysctl_events_retry_timeout;

	int			sysctl_acct;

	int			sysctl_tstamp;

	int			sysctl_checksum;

	unsigned int		sysctl_log_invalid; /* Log invalid packets */

	int			sysctl_auto_assign_helper;

	bool			auto_assign_helper_warned;

	struct nf_ip_net	nf_ct_proto;

#if defined(CONFIG_NF_CONNTRACK_LABELS)

	unsigned int		labels_used;
@@ -92,13 +101,5 @@ struct netns_ct { 
	struct hlist_head	*nat_bysource;

	unsigned int		nat_htable_size;

#endif

#ifdef CONFIG_SYSCTL

	struct ctl_table_header	*sysctl_header;

	struct ctl_table_header	*acct_sysctl_header;

	struct ctl_table_header	*tstamp_sysctl_header;

	struct ctl_table_header	*event_sysctl_header;

	struct ctl_table_header	*helper_sysctl_header;

#endif

	char			*slabname;

};

#endif

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