[PATCH 25/29] netfilter: nf_conntrack: ensure that CONNTRACK_LOCKS is power of 2

[Pablo Neira Ayuso]

From: Li RongQing <lirongq...@baidu.com>

CONNTRACK_LOCKS is divisor when computer array index, if it is power of
2, compiler will optimize modulo operation as bitwise AND, or else
modulo will lower performance.

Suggested-by: Florian Westphal <f...@strlen.de>
Signed-off-by: Li RongQing <lirongq...@baidu.com>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/nf_conntrack_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_conntrack_core.c 
b/net/netfilter/nf_conntrack_core.c
index ff9313c579b4..82bfbeef46af 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -2480,6 +2480,7 @@ int nf_conntrack_init_net(struct net *net)
        int cpu;
 
        BUILD_BUG_ON(IP_CT_UNTRACKED == IP_CT_NUMBER);
+       BUILD_BUG_ON_NOT_POWER_OF_2(CONNTRACK_LOCKS);
        atomic_set(&net->ct.count, 0);
 
        net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
-- 
2.11.0