From a627266570605a98c5fda5b8234d9e92015e4d14 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 28 Aug 2008 01:11:25 -0700 Subject: [PATCH] ip: speedup /proc/net/rt_cache handling When scanning route cache hash table, we can avoid taking locks for empty buckets. Both /proc/net/rt_cache and NETLINK RTM_GETROUTE interface are taken into account. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/route.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index cca921ea8550..71598f64c113 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -282,6 +282,8 @@ static struct rtable *rt_cache_get_first(struct seq_file *seq) struct rtable *r = NULL; for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { + if (!rt_hash_table[st->bucket].chain) + continue; rcu_read_lock_bh(); r = rcu_dereference(rt_hash_table[st->bucket].chain); while (r) { @@ -299,11 +301,14 @@ static struct rtable *__rt_cache_get_next(struct seq_file *seq, struct rtable *r) { struct rt_cache_iter_state *st = seq->private; + r = r->u.dst.rt_next; while (!r) { rcu_read_unlock_bh(); - if (--st->bucket < 0) - break; + do { + if (--st->bucket < 0) + return NULL; + } while (!rt_hash_table[st->bucket].chain); rcu_read_lock_bh(); r = rt_hash_table[st->bucket].chain; } @@ -2840,7 +2845,9 @@ int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) if (s_h < 0) s_h = 0; s_idx = idx = cb->args[1]; - for (h = s_h; h <= rt_hash_mask; h++) { + for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { + if (!rt_hash_table[h].chain) + continue; rcu_read_lock_bh(); for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt; rt = rcu_dereference(rt->u.dst.rt_next), idx++) { @@ -2859,7 +2866,6 @@ int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) dst_release(xchg(&skb->dst, NULL)); } rcu_read_unlock_bh(); - s_idx = 0; } done: -- 2.34.1