ipv6/addrconf: speedup /proc/net/if_inet6 filling
This ensures a linear behaviour when filling /proc/net/if_inet6 thus making
ifconfig run really fast on IPv6 only addresses. In fact, with this patch and
the IPv4 one sent a while ago, ifconfig will run in linear time regardless of
address type.
IPv4 related patch: f04565ddf52e401880f8ba51de0dff8ba51c99fd
dev: use name hash for dev_seq_ops
...
Some statistics (running ifconfig > /dev/null on a different setup):
iface count / IPv6 no-patch time / IPv6 patched time / IPv4 time
----------------------------------------------------------------
6250 | 0.23 s | 0.13 s | 0.11 s
12500 | 0.62 s | 0.28 s | 0.22 s
25000 | 2.91 s | 0.57 s | 0.46 s
50000 | 11.37 s | 1.21 s | 0.94 s
128000 | 86.78 s | 3.05 s | 2.54 s
Signed-off-by: Mihai Maruseac <mmaruseac@ixiacom.com>
Cc: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3513cce..0ba0866 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3068,20 +3068,39 @@
struct if6_iter_state {
struct seq_net_private p;
int bucket;
+ int offset;
};
-static struct inet6_ifaddr *if6_get_first(struct seq_file *seq)
+static struct inet6_ifaddr *if6_get_first(struct seq_file *seq, loff_t pos)
{
struct inet6_ifaddr *ifa = NULL;
struct if6_iter_state *state = seq->private;
struct net *net = seq_file_net(seq);
+ int p = 0;
- for (state->bucket = 0; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) {
+ /* initial bucket if pos is 0 */
+ if (pos == 0) {
+ state->bucket = 0;
+ state->offset = 0;
+ }
+
+ for (; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) {
struct hlist_node *n;
hlist_for_each_entry_rcu_bh(ifa, n, &inet6_addr_lst[state->bucket],
- addr_lst)
+ addr_lst) {
+ /* sync with offset */
+ if (p < state->offset) {
+ p++;
+ continue;
+ }
+ state->offset++;
if (net_eq(dev_net(ifa->idev->dev), net))
return ifa;
+ }
+
+ /* prepare for next bucket */
+ state->offset = 0;
+ p = 0;
}
return NULL;
}
@@ -3093,13 +3112,17 @@
struct net *net = seq_file_net(seq);
struct hlist_node *n = &ifa->addr_lst;
- hlist_for_each_entry_continue_rcu_bh(ifa, n, addr_lst)
+ hlist_for_each_entry_continue_rcu_bh(ifa, n, addr_lst) {
+ state->offset++;
if (net_eq(dev_net(ifa->idev->dev), net))
return ifa;
+ }
while (++state->bucket < IN6_ADDR_HSIZE) {
+ state->offset = 0;
hlist_for_each_entry_rcu_bh(ifa, n,
&inet6_addr_lst[state->bucket], addr_lst) {
+ state->offset++;
if (net_eq(dev_net(ifa->idev->dev), net))
return ifa;
}
@@ -3108,21 +3131,11 @@
return NULL;
}
-static struct inet6_ifaddr *if6_get_idx(struct seq_file *seq, loff_t pos)
-{
- struct inet6_ifaddr *ifa = if6_get_first(seq);
-
- if (ifa)
- while (pos && (ifa = if6_get_next(seq, ifa)) != NULL)
- --pos;
- return pos ? NULL : ifa;
-}
-
static void *if6_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(rcu_bh)
{
rcu_read_lock_bh();
- return if6_get_idx(seq, *pos);
+ return if6_get_first(seq, *pos);
}
static void *if6_seq_next(struct seq_file *seq, void *v, loff_t *pos)