diff options
| -rw-r--r-- | net/ipv4/route.c | 50 |
1 files changed, 38 insertions, 12 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index b2ba5581d2ae..d9b40248b97f 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -146,7 +146,6 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); static void ipv4_link_failure(struct sk_buff *skb); static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu); static int rt_garbage_collect(struct dst_ops *ops); -static void rt_emergency_hash_rebuild(struct net *net); static struct dst_ops ipv4_dst_ops = { @@ -780,11 +779,30 @@ static void rt_do_flush(int process_context) #define FRACT_BITS 3 #define ONE (1UL << FRACT_BITS) +/* + * Given a hash chain and an item in this hash chain, + * find if a previous entry has the same hash_inputs + * (but differs on tos, mark or oif) + * Returns 0 if an alias is found. + * Returns ONE if rth has no alias before itself. + */ +static int has_noalias(const struct rtable *head, const struct rtable *rth) +{ + const struct rtable *aux = head; + + while (aux != rth) { + if (compare_hash_inputs(&aux->fl, &rth->fl)) + return 0; + aux = aux->u.dst.rt_next; + } + return ONE; +} + static void rt_check_expire(void) { static unsigned int rover; unsigned int i = rover, goal; - struct rtable *rth, *aux, **rthp; + struct rtable *rth, **rthp; unsigned long samples = 0; unsigned long sum = 0, sum2 = 0; unsigned long delta; @@ -835,15 +853,7 @@ nofree: * attributes don't unfairly skew * the length computation */ - for (aux = rt_hash_table[i].chain;;) { - if (aux == rth) { - length += ONE; - break; - } - if (compare_hash_inputs(&aux->fl, &rth->fl)) - break; - aux = aux->u.dst.rt_next; - } + length += has_noalias(rt_hash_table[i].chain, rth); continue; } } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) @@ -1073,6 +1083,21 @@ work_done: out: return 0; } +/* + * Returns number of entries in a hash chain that have different hash_inputs + */ +static int slow_chain_length(const struct rtable *head) +{ + int length = 0; + const struct rtable *rth = head; + + while (rth) { + length += has_noalias(head, rth); + rth = rth->u.dst.rt_next; + } + return length >> FRACT_BITS; +} + static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp, struct sk_buff *skb) { @@ -1185,7 +1210,8 @@ restart: rt_free(cand); } } else { - if (chain_length > rt_chain_length_max) { + if (chain_length > rt_chain_length_max && + slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) { struct net *net = dev_net(rt->u.dst.dev); int num = ++net->ipv4.current_rt_cache_rebuild_count; if (!rt_caching(dev_net(rt->u.dst.dev))) { |