From 8cf4d6a224a0226987d9cba69cb46d93814fe449 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Fri, 15 Nov 2013 15:57:53 +0100 Subject: [PATCH] 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: Jesper Dangaard Brouer Reviewed-by: Jiri Benc Signed-off-by: Pablo Neira Ayuso --- include/net/netns/conntrack.h | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h index c9c0c538b68b..fbcc7fa536dc 100644 --- a/include/net/netns/conntrack.h +++ b/include/net/netns/conntrack.h @@ -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 -- 2.20.1