xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ipv6: add ipv6_addr_hash() helper

Browse Source 
Introduce ipv6_addr_hash() helper doing a XOR on all bits
of an IPv6 address, with an optimized x86_64 version.

Use it in flow dissector, as suggested by Andrew McGregor,
to reduce hash collision probabilities in fq_codel (and other
users of flow dissector)

Use it in ip6_tunnel.c and use more bit shuffling, as suggested
by David Laight, as existing hash was ignoring most of them.

Use it in sunrpc and use more bit shuffling, using hash_32().

Use it in net/ipv6/addrconf.c, using hash_32() as well.

As a cleanup, use it in net/ipv4/tcp_metrics.c

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew McGregor <andrewmcgr@gmail.com>
Cc: Dave Taht <dave.taht@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2012-07-18 08:11:12 +00:00
committed by David S. Miller
parent dc9059512c
commit ddbe503203
7 changed files with 45 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
net/ipv6/addrconf.c
View File

@@ -63,6 +63,7 @@
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/string.h>
#include <linux/hash.h>
#include <net/net_namespace.h>
#include <net/sock.h>
@@ -579,15 +580,9 @@ ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
list_add_tail(&ifp->if_list, p);
}
static u32 ipv6_addr_hash(const struct in6_addr *addr)
static u32 inet6_addr_hash(const struct in6_addr *addr)
{
/*
* We perform the hash function over the last 64 bits of the address
* This will include the IEEE address token on links that support it.
*/
return jhash_2words((__force u32)addr->s6_addr32[2],
(__force u32)addr->s6_addr32[3], 0)
& (IN6_ADDR_HSIZE - 1);
return hash_32(ipv6_addr_hash(addr), IN6_ADDR_HSIZE_SHIFT);
}
/* On success it returns ifp with increased reference count */
@@ -662,7 +657,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
in6_ifa_hold(ifa);
/* Add to big hash table */
hash = ipv6_addr_hash(addr);
hash = inet6_addr_hash(addr);
hlist_add_head_rcu(&ifa->addr_lst, &inet6_addr_lst[hash]);
spin_unlock(&addrconf_hash_lock);
@@ -1270,7 +1265,7 @@ int ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
{
struct inet6_ifaddr *ifp;
struct hlist_node *node;
unsigned int hash = ipv6_addr_hash(addr);
unsigned int hash = inet6_addr_hash(addr);
rcu_read_lock_bh();
hlist_for_each_entry_rcu(ifp, node, &inet6_addr_lst[hash], addr_lst) {
@@ -1293,7 +1288,7 @@ EXPORT_SYMBOL(ipv6_chk_addr);
static bool ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
struct net_device *dev)
{
unsigned int hash = ipv6_addr_hash(addr);
unsigned int hash = inet6_addr_hash(addr);
struct inet6_ifaddr *ifp;
struct hlist_node *node;
@@ -1336,7 +1331,7 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add
struct net_device *dev, int strict)
{
struct inet6_ifaddr *ifp, *result = NULL;
unsigned int hash = ipv6_addr_hash(addr);
unsigned int hash = inet6_addr_hash(addr);
struct hlist_node *node;
rcu_read_lock_bh();
@@ -3223,7 +3218,7 @@ int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr)
int ret = 0;
struct inet6_ifaddr *ifp = NULL;
struct hlist_node *n;
unsigned int hash = ipv6_addr_hash(addr);
unsigned int hash = inet6_addr_hash(addr);
rcu_read_lock_bh();
hlist_for_each_entry_rcu_bh(ifp, n, &inet6_addr_lst[hash], addr_lst) {