From 026ace060dfe29275d2188297a62fa37d6c1a02c Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Thu, 21 Mar 2013 11:58:06 +0200 Subject: ipvs: optimize dst usage for real server Currently when forwarding requests to real servers we use dst_lock and atomic operations when cloning the dst_cache value. As the dst_cache value does not change most of the time it is better to use RCU and to lock dst_lock only when we need to replace the obsoleted dst. For this to work we keep dst_cache in new structure protected by RCU. For packets to remote real servers we will use noref version of dst_cache, it will be valid while we are in RCU read-side critical section because now dst_release for replaced dsts will be invoked after the grace period. Packets to local real servers that are passed to local stack with NF_ACCEPT need a dst clone. Signed-off-by: Julian Anastasov Signed-off by: Hans Schillstrom Signed-off-by: Simon Horman --- include/net/ip_vs.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'include/net') diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 8ad73a834655..a150ff5d838c 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -724,6 +724,13 @@ struct ip_vs_service { struct ip_vs_pe *pe; }; +/* Information for cached dst */ +struct ip_vs_dest_dst { + struct dst_entry *dst_cache; /* destination cache entry */ + u32 dst_cookie; + union nf_inet_addr dst_saddr; + struct rcu_head rcu_head; +}; /* * The real server destination forwarding entry @@ -752,9 +759,7 @@ struct ip_vs_dest { /* for destination cache */ spinlock_t dst_lock; /* lock of dst_cache */ - struct dst_entry *dst_cache; /* destination cache entry */ - u32 dst_cookie; - union nf_inet_addr dst_saddr; + struct ip_vs_dest_dst __rcu *dest_dst; /* cached dst info */ /* for virtual service */ struct ip_vs_service *svc; /* service it belongs to */ @@ -1427,6 +1432,7 @@ extern int ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, extern int ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, int offset, unsigned int hooknum, struct ip_vs_iphdr *iph); +extern void ip_vs_dest_dst_rcu_free(struct rcu_head *head); #ifdef CONFIG_IP_VS_IPV6 extern int ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, -- cgit v1.2.3