Eric Dumazet wrote:

[PATCH] netfilter: Get rid of central rwlock in tcp conntracking

TCP connection tracking suffers of huge contention on a global rwlock,
used to protect tcp conntracking state.

As each tcp conntrack state have no relations between each others, we
can switch to fine grained lock. Using an array of spinlocks avoids
enlarging size of connection tracking structures, yet giving reasonable
fanout.

tcp_print_conntrack() doesnt need to lock anything to read
ct->proto.tcp.state, so speedup /proc/net/ip_conntrack as well.

nf_conntrack_hash_rnd_initted & nf_conntrack_hash_rnd declared read_mostly
  

This looks good to me. Rick, would you like to give it a try?

I'll convert the remaining conntrack protocols when applying it.