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| author | Julian Anastasov | 2013-03-21 10:58:06 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso | 2013-04-02 00:23:42 +0200 |
| commit | 026ace060dfe29275d2188297a62fa37d6c1a02c (patch) | |
| tree | ed61c22b342c82a64ca16e97a356acff94bc930c /net/netfilter/ipvs/ip_vs_core.c | |
| parent | ipvs: consolidate all dst checks on transmit in one place (diff) | |
| download | kernel-qcow2-linux-026ace060dfe29275d2188297a62fa37d6c1a02c.tar.gz kernel-qcow2-linux-026ace060dfe29275d2188297a62fa37d6c1a02c.tar.xz kernel-qcow2-linux-026ace060dfe29275d2188297a62fa37d6c1a02c.zip | |
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 <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_core.c')
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_core.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 2aef23ed748b..6ad24e7ef440 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1395,10 +1395,13 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) goto ignore_ipip; /* Prefer the resulting PMTU */ if (dest) { - spin_lock(&dest->dst_lock); - if (dest->dst_cache) - mtu = dst_mtu(dest->dst_cache); - spin_unlock(&dest->dst_lock); + struct ip_vs_dest_dst *dest_dst; + + rcu_read_lock(); + dest_dst = rcu_dereference(dest->dest_dst); + if (dest_dst) + mtu = dst_mtu(dest_dst->dst_cache); + rcu_read_unlock(); } if (mtu > 68 + sizeof(struct iphdr)) mtu -= sizeof(struct iphdr); |