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ipv4: change inet_addr_hash()

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Use net_hash_mix(net) instead of hash_ptr(net, 8), and use
hash_32() instead of using a serie of XOR

Define IN4_ADDR_HSIZE_SHIFT for clarity

__ip_dev_find() can perform the net_eq() call only if ifa_local
matches the key, to avoid unneeded dereferences.

remove inline attributes

# size net/ipv4/devinet.o.before net/ipv4/devinet.o
   text	   data	    bss	    dec	    hex	filename
  17471	   2545	   2048	  22064	   5630	net/ipv4/devinet.o.before
  17335	   2545	   2048	  21928	   55a8	net/ipv4/devinet.o

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-08-03 21:06:50 +00:00 committed by David S. Miller
parent 47061bc440
commit 40384999d1
1 changed files with 18 additions and 21 deletions
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39
net/ipv4/devinet.c
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@ -94,25 +94,22 @@ static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
[IFA_LABEL] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
};
/* inet_addr_hash's shifting is dependent upon this IN4_ADDR_HSIZE
* value. So if you change this define, make appropriate changes to
* inet_addr_hash as well.
*/
#define IN4_ADDR_HSIZE 256
#define IN4_ADDR_HSIZE_SHIFT 8
#define IN4_ADDR_HSIZE (1U << IN4_ADDR_HSIZE_SHIFT)
static struct hlist_head inet_addr_lst[IN4_ADDR_HSIZE];
static DEFINE_SPINLOCK(inet_addr_hash_lock);
static inline unsigned int inet_addr_hash(struct net *net, __be32 addr)
static u32 inet_addr_hash(struct net *net, __be32 addr)
{
u32 val = (__force u32) addr ^ hash_ptr(net, 8);
u32 val = (__force u32) addr ^ net_hash_mix(net);
return ((val ^ (val >> 8) ^ (val >> 16) ^ (val >> 24)) &
(IN4_ADDR_HSIZE - 1));
return hash_32(val, IN4_ADDR_HSIZE_SHIFT);
}
static void inet_hash_insert(struct net *net, struct in_ifaddr *ifa)
{
unsigned int hash = inet_addr_hash(net, ifa->ifa_local);
u32 hash = inet_addr_hash(net, ifa->ifa_local);
spin_lock(&inet_addr_hash_lock);
hlist_add_head_rcu(&ifa->hash, &inet_addr_lst[hash]);
@ -136,18 +133,18 @@ static void inet_hash_remove(struct in_ifaddr *ifa)
*/
struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
{
unsigned int hash = inet_addr_hash(net, addr);
u32 hash = inet_addr_hash(net, addr);
struct net_device *result = NULL;
struct in_ifaddr *ifa;
struct hlist_node *node;
rcu_read_lock();
hlist_for_each_entry_rcu(ifa, node, &inet_addr_lst[hash], hash) {
struct net_device *dev = ifa->ifa_dev->dev;
if (!net_eq(dev_net(dev), net))
continue;
if (ifa->ifa_local == addr) {
struct net_device *dev = ifa->ifa_dev->dev;
if (!net_eq(dev_net(dev), net))
continue;
result = dev;
break;
}
@ -182,10 +179,10 @@ static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
static void devinet_sysctl_register(struct in_device *idev);
static void devinet_sysctl_unregister(struct in_device *idev);
#else
static inline void devinet_sysctl_register(struct in_device *idev)
static void devinet_sysctl_register(struct in_device *idev)
{
}
static inline void devinet_sysctl_unregister(struct in_device *idev)
static void devinet_sysctl_unregister(struct in_device *idev)
{
}
#endif
@ -205,7 +202,7 @@ static void inet_rcu_free_ifa(struct rcu_head *head)
kfree(ifa);
}
static inline void inet_free_ifa(struct in_ifaddr *ifa)
static void inet_free_ifa(struct in_ifaddr *ifa)
{
call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
}
@ -659,7 +656,7 @@ static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg
* Determine a default network mask, based on the IP address.
*/
static inline int inet_abc_len(__be32 addr)
static int inet_abc_len(__be32 addr)
{
int rc = -1; /* Something else, probably a multicast. */
@ -1124,7 +1121,7 @@ skip:
}
}
static inline bool inetdev_valid_mtu(unsigned int mtu)
static bool inetdev_valid_mtu(unsigned int mtu)
{
return mtu >= 68;
}
@ -1239,7 +1236,7 @@ static struct notifier_block ip_netdev_notifier = {
.notifier_call = inetdev_event,
};
static inline size_t inet_nlmsg_size(void)
static size_t inet_nlmsg_size(void)
{
return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+ nla_total_size(4) /* IFA_ADDRESS */