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 <brouer@redhat.com>
Reviewed-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
index c9c0c53..fbcc7fa 100644
--- a/include/net/netns/conntrack.h
+++ b/include/net/netns/conntrack.h
@@ -65,6 +65,23 @@
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 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 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