From 0b4419162aa6c4204843f3a13b48d9ab821d3167 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Mon, 16 Jun 2008 17:14:11 -0700 Subject: netns: introduce the net_hash_mix "salt" for hashes There are many possible ways to add this "salt", thus I made this patch to be the last in the series to change it if required. Currently I propose to use the struct net pointer itself as this salt, but since this pointer is most often cache-line aligned, shift this right to eliminate the bits, that are most often zeroed. After this, simply add this mix to prepared hashfn-s. For CONFIG_NET_NS=n case this salt is 0 and no changes in hashfn appear. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- include/linux/udp.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/udp.h') diff --git a/include/linux/udp.h b/include/linux/udp.h index 3deccac2e815..0cf5c4c0ec81 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -38,6 +38,7 @@ struct udphdr { #ifdef __KERNEL__ #include #include +#include static inline struct udphdr *udp_hdr(const struct sk_buff *skb) { @@ -48,7 +49,7 @@ static inline struct udphdr *udp_hdr(const struct sk_buff *skb) static inline int udp_hashfn(struct net *net, const unsigned num) { - return num & (UDP_HTABLE_SIZE - 1); + return (num + net_hash_mix(net)) & (UDP_HTABLE_SIZE - 1); } struct udp_sock { -- cgit