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ipv6: speedup inet6_dump_addr()

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When handling large number of netdevices, inet6_dump_addr()
is very slow because it has O(N^2) complexity.

Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
sub lists of the dev_index hash table, and RCU lookups.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2009-11-12 04:11:50 +00:00
committed by David S. Miller
parent 5256f2ef3a
commit 234b27c3fd
1 changed files with 101 additions and 78 deletions
Download Patch File Download Diff File Expand all files Collapse all files

179
net/ipv6/addrconf.c
View File

@@ -3481,91 +3481,114 @@ enum addr_type_t
ANYCAST_ADDR, ANYCAST_ADDR,
}; };
static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, /* called with rcu_read_lock() */
enum addr_type_t type) static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
struct netlink_callback *cb, enum addr_type_t type,
int s_ip_idx, int *p_ip_idx)
{ {
int idx, ip_idx;
int s_idx, s_ip_idx;
int err = 1;
struct net_device *dev;
struct inet6_dev *idev = NULL;
struct inet6_ifaddr *ifa; struct inet6_ifaddr *ifa;
struct ifmcaddr6 *ifmca; struct ifmcaddr6 *ifmca;
struct ifacaddr6 *ifaca; struct ifacaddr6 *ifaca;
struct net *net = sock_net(skb->sk); int err = 1;
int ip_idx = *p_ip_idx;
s_idx = cb->args[0]; read_lock_bh(&idev->lock);
s_ip_idx = ip_idx = cb->args[1]; switch (type) {
case UNICAST_ADDR:
idx = 0; /* unicast address incl. temp addr */
for_each_netdev(net, dev) { for (ifa = idev->addr_list; ifa;
if (idx < s_idx) ifa = ifa->if_next, ip_idx++) {
goto cont; if (ip_idx < s_ip_idx)
if (idx > s_idx) continue;
s_ip_idx = 0; err = inet6_fill_ifaddr(skb, ifa,
ip_idx = 0; NETLINK_CB(cb->skb).pid,
if ((idev = in6_dev_get(dev)) == NULL) cb->nlh->nlmsg_seq,
goto cont; RTM_NEWADDR,
read_lock_bh(&idev->lock); NLM_F_MULTI);
switch (type) { if (err <= 0)
case UNICAST_ADDR: break;
/* unicast address incl. temp addr */
for (ifa = idev->addr_list; ifa;
ifa = ifa->if_next, ip_idx++) {
if (ip_idx < s_ip_idx)
continue;
err = inet6_fill_ifaddr(skb, ifa,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
RTM_NEWADDR,
NLM_F_MULTI);
if (err <= 0)
break;
}
break;
case MULTICAST_ADDR:
/* multicast address */
for (ifmca = idev->mc_list; ifmca;
ifmca = ifmca->next, ip_idx++) {
if (ip_idx < s_ip_idx)
continue;
err = inet6_fill_ifmcaddr(skb, ifmca,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
RTM_GETMULTICAST,
NLM_F_MULTI);
if (err <= 0)
break;
}
break;
case ANYCAST_ADDR:
/* anycast address */
for (ifaca = idev->ac_list; ifaca;
ifaca = ifaca->aca_next, ip_idx++) {
if (ip_idx < s_ip_idx)
continue;
err = inet6_fill_ifacaddr(skb, ifaca,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
RTM_GETANYCAST,
NLM_F_MULTI);
if (err <= 0)
break;
}
break;
default:
break;
} }
read_unlock_bh(&idev->lock); break;
in6_dev_put(idev); case MULTICAST_ADDR:
/* multicast address */
if (err <= 0) for (ifmca = idev->mc_list; ifmca;
break; ifmca = ifmca->next, ip_idx++) {
cont: if (ip_idx < s_ip_idx)
idx++; continue;
err = inet6_fill_ifmcaddr(skb, ifmca,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
RTM_GETMULTICAST,
NLM_F_MULTI);
if (err <= 0)
break;
}
break;
case ANYCAST_ADDR:
/* anycast address */
for (ifaca = idev->ac_list; ifaca;
ifaca = ifaca->aca_next, ip_idx++) {
if (ip_idx < s_ip_idx)
continue;
err = inet6_fill_ifacaddr(skb, ifaca,
NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
RTM_GETANYCAST,
NLM_F_MULTI);
if (err <= 0)
break;
}
break;
default:
break;
} }
cb->args[0] = idx; read_unlock_bh(&idev->lock);
cb->args[1] = ip_idx; *p_ip_idx = ip_idx;
return err;
}
static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
enum addr_type_t type)
{
struct net *net = sock_net(skb->sk);
int h, s_h;
int idx, ip_idx;
int s_idx, s_ip_idx;
struct net_device *dev;
struct inet6_dev *idev;
struct hlist_head *head;
struct hlist_node *node;
s_h = cb->args[0];
s_idx = idx = cb->args[1];
s_ip_idx = ip_idx = cb->args[2];
rcu_read_lock();
for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
idx = 0;
head = &net->dev_index_head[h];
hlist_for_each_entry_rcu(dev, node, head, index_hlist) {
if (idx < s_idx)
goto cont;
if (idx > s_idx)
s_ip_idx = 0;
ip_idx = 0;
if ((idev = __in6_dev_get(dev)) == NULL)
goto cont;
if (in6_dump_addrs(idev, skb, cb, type,
s_ip_idx, &ip_idx) <= 0)
goto done;
cont:
idx++;
}
}
done:
rcu_read_unlock();
cb->args[0] = h;
cb->args[1] = idx;
cb->args[2] = ip_idx;
return skb->len; return skb->len;
} }