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>
This commit is contained in:
Jesper Dangaard Brouer 2013-11-15 15:57:53 +01:00 committed by Pablo Neira Ayuso
parent 6853605360
commit 8cf4d6a224
1 changed files with 17 additions and 16 deletions

View File

@ -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