From 1d5783030a14d1b6ee763f63c8136e581f48b365 Mon Sep 17 00:00:00 2001 From: Mihai Maruseac Date: Tue, 3 Jan 2012 23:31:35 +0000 Subject: 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 Cc: Daniel Baluta Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 43 ++++++++++++++++++++++++++++--------------- 1 file changed, 28 insertions(+), 15 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 3513cceba50..0ba0866230c 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3068,20 +3068,39 @@ static void addrconf_dad_run(struct inet6_dev *idev) 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 @@ static struct inet6_ifaddr *if6_get_next(struct seq_file *seq, 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 @@ static struct inet6_ifaddr *if6_get_next(struct seq_file *seq, 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) -- cgit v1.2.3