From: Simon Kirby <sim@netnation.com>
Date: Tue, 17 Jun 2003 15:50:36 -0700
so the problems in 2.4 are probably the result of me hacking in the
2.5 patch.
I have them in my pending 2.4.x tree, try this:
diff -Nru a/include/net/route.h b/include/net/route.h
--- a/include/net/route.h Tue Jun 17 16:08:06 2003
+++ b/include/net/route.h Tue Jun 17 16:08:06 2003
@@ -114,6 +114,8 @@
unsigned int gc_ignored;
unsigned int gc_goal_miss;
unsigned int gc_dst_overflow;
+ unsigned int in_hlist_search;
+ unsigned int out_hlist_search;
} ____cacheline_aligned_in_smp;
extern struct ip_rt_acct *ip_rt_acct;
diff -Nru a/net/ipv4/Config.in b/net/ipv4/Config.in
--- a/net/ipv4/Config.in Tue Jun 17 16:08:06 2003
+++ b/net/ipv4/Config.in Tue Jun 17 16:08:06 2003
@@ -14,7 +14,6 @@
bool ' IP: equal cost multipath' CONFIG_IP_ROUTE_MULTIPATH
bool ' IP: use TOS value as routing key' CONFIG_IP_ROUTE_TOS
bool ' IP: verbose route monitoring' CONFIG_IP_ROUTE_VERBOSE
- bool ' IP: large routing tables' CONFIG_IP_ROUTE_LARGE_TABLES
fi
bool ' IP: kernel level autoconfiguration' CONFIG_IP_PNP
if [ "$CONFIG_IP_PNP" = "y" ]; then
diff -Nru a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
--- a/net/ipv4/fib_hash.c Tue Jun 17 16:08:07 2003
+++ b/net/ipv4/fib_hash.c Tue Jun 17 16:08:07 2003
@@ -89,7 +89,7 @@
int fz_nent; /* Number of entries */
int fz_divisor; /* Hash divisor */
- u32 fz_hashmask; /* (1<<fz_divisor) - 1 */
+ u32 fz_hashmask; /* (fz_divisor - 1) */
#define FZ_HASHMASK(fz) ((fz)->fz_hashmask)
int fz_order; /* Zone order */
@@ -149,9 +149,19 @@
static rwlock_t fib_hash_lock = RW_LOCK_UNLOCKED;
-#define FZ_MAX_DIVISOR 1024
+#define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct fib_node *))
-#ifdef CONFIG_IP_ROUTE_LARGE_TABLES
+static struct fib_node **fz_hash_alloc(int divisor)
+{
+ unsigned long size = divisor * sizeof(struct fib_node *);
+
+ if (divisor <= 1024) {
+ return kmalloc(size, GFP_KERNEL);
+ } else {
+ return (struct fib_node **)
+ __get_free_pages(GFP_KERNEL, get_order(size));
+ }
+}
/* The fib hash lock must be held when this is called. */
static __inline__ void fn_rebuild_zone(struct fn_zone *fz,
@@ -174,6 +184,15 @@
}
}
+static void fz_hash_free(struct fib_node **hash, int divisor)
+{
+ if (divisor <= 1024)
+ kfree(hash);
+ else
+ free_pages((unsigned long) hash,
+ get_order(divisor * sizeof(struct fib_node *)));
+}
+
static void fn_rehash_zone(struct fn_zone *fz)
{
struct fib_node **ht, **old_ht;
@@ -185,24 +204,30 @@
switch (old_divisor) {
case 16:
new_divisor = 256;
- new_hashmask = 0xFF;
break;
case 256:
new_divisor = 1024;
- new_hashmask = 0x3FF;
break;
default:
- printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
- return;
+ if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
+ printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
+ return;
+ }
+ new_divisor = (old_divisor << 1);
+ break;
}
+
+ new_hashmask = (new_divisor - 1);
+
#if RT_CACHE_DEBUG >= 2
printk("fn_rehash_zone: hash for zone %d grows from %d\n", fz->fz_order, old_divisor);
#endif
- ht = kmalloc(new_divisor*sizeof(struct fib_node*), GFP_KERNEL);
+ ht = fz_hash_alloc(new_divisor);
if (ht) {
memset(ht, 0, new_divisor*sizeof(struct fib_node*));
+
write_lock_bh(&fib_hash_lock);
old_ht = fz->fz_hash;
fz->fz_hash = ht;
@@ -210,10 +235,10 @@
fz->fz_divisor = new_divisor;
fn_rebuild_zone(fz, old_ht, old_divisor);
write_unlock_bh(&fib_hash_lock);
- kfree(old_ht);
+
+ fz_hash_free(old_ht, old_divisor);
}
}
-#endif /* CONFIG_IP_ROUTE_LARGE_TABLES */
static void fn_free_node(struct fib_node * f)
{
@@ -233,12 +258,11 @@
memset(fz, 0, sizeof(struct fn_zone));
if (z) {
fz->fz_divisor = 16;
- fz->fz_hashmask = 0xF;
} else {
fz->fz_divisor = 1;
- fz->fz_hashmask = 0;
}
- fz->fz_hash = kmalloc(fz->fz_divisor*sizeof(struct fib_node*), GFP_KERNEL);
+ fz->fz_hashmask = (fz->fz_divisor - 1);
+ fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
if (!fz->fz_hash) {
kfree(fz);
return NULL;
@@ -467,12 +491,10 @@
if ((fi = fib_create_info(r, rta, n, &err)) == NULL)
return err;
-#ifdef CONFIG_IP_ROUTE_LARGE_TABLES
- if (fz->fz_nent > (fz->fz_divisor<<2) &&
+ if (fz->fz_nent > (fz->fz_divisor<<1) &&
fz->fz_divisor < FZ_MAX_DIVISOR &&
(z==32 || (1<<z) > fz->fz_divisor))
fn_rehash_zone(fz);
-#endif
fp = fz_chain_p(key, fz);
diff -Nru a/net/ipv4/route.c b/net/ipv4/route.c
--- a/net/ipv4/route.c Tue Jun 17 16:08:07 2003
+++ b/net/ipv4/route.c Tue Jun 17 16:08:07 2003
@@ -108,7 +108,7 @@
int ip_rt_max_size;
int ip_rt_gc_timeout = RT_GC_TIMEOUT;
int ip_rt_gc_interval = 60 * HZ;
-int ip_rt_gc_min_interval = 5 * HZ;
+int ip_rt_gc_min_interval = HZ / 2;
int ip_rt_redirect_number = 9;
int ip_rt_redirect_load = HZ / 50;
int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
@@ -287,7 +287,7 @@
for (lcpu = 0; lcpu < smp_num_cpus; lcpu++) {
i = cpu_logical_map(lcpu);
- len += sprintf(buffer+len, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
+ len += sprintf(buffer+len, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
dst_entries,
rt_cache_stat[i].in_hit,
rt_cache_stat[i].in_slow_tot,
@@ -304,7 +304,9 @@
rt_cache_stat[i].gc_total,
rt_cache_stat[i].gc_ignored,
rt_cache_stat[i].gc_goal_miss,
- rt_cache_stat[i].gc_dst_overflow
+ rt_cache_stat[i].gc_dst_overflow,
+ rt_cache_stat[i].in_hlist_search,
+ rt_cache_stat[i].out_hlist_search
);
}
@@ -344,16 +346,17 @@
rth->u.dst.expires;
}
-static __inline__ int rt_may_expire(struct rtable *rth, int tmo1, int tmo2)
+static __inline__ int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
{
- int age;
+ unsigned long age;
int ret = 0;
if (atomic_read(&rth->u.dst.__refcnt))
goto out;
ret = 1;
- if (rth->u.dst.expires && (long)(rth->u.dst.expires - jiffies) <= 0)
+ if (rth->u.dst.expires &&
+ time_after_eq(jiffies, rth->u.dst.expires))
goto out;
age = jiffies - rth->u.dst.lastuse;
@@ -365,6 +368,25 @@
out: return ret;
}
+/* Bits of score are:
+ * 31: very valuable
+ * 30: not quite useless
+ * 29..0: usage counter
+ */
+static inline u32 rt_score(struct rtable *rt)
+{
+ u32 score = rt->u.dst.__use;
+
+ if (rt_valuable(rt))
+ score |= (1<<31);
+
+ if (!rt->key.iif ||
+ !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
+ score |= (1<<30);
+
+ return score;
+}
+
/* This runs via a timer and thus is always in BH context. */
static void SMP_TIMER_NAME(rt_check_expire)(unsigned long dummy)
{
@@ -375,7 +397,7 @@
for (t = ip_rt_gc_interval << rt_hash_log; t >= 0;
t -= ip_rt_gc_timeout) {
- unsigned tmo = ip_rt_gc_timeout;
+ unsigned long tmo = ip_rt_gc_timeout;
i = (i + 1) & rt_hash_mask;
rthp = &rt_hash_table[i].chain;
@@ -384,7 +406,7 @@
while ((rth = *rthp) != NULL) {
if (rth->u.dst.expires) {
/* Entry is expired even if it is in use */
- if ((long)(now - rth->u.dst.expires) <= 0) {
+ if (time_before_eq(now, rth->u.dst.expires)) {
tmo >>= 1;
rthp = &rth->u.rt_next;
continue;
@@ -402,7 +424,7 @@
write_unlock(&rt_hash_table[i].lock);
/* Fallback loop breaker. */
- if ((jiffies - now) > 0)
+ if (time_after(jiffies, now))
break;
}
rover = i;
@@ -504,7 +526,7 @@
static int rt_garbage_collect(void)
{
- static unsigned expire = RT_GC_TIMEOUT;
+ static unsigned long expire = RT_GC_TIMEOUT;
static unsigned long last_gc;
static int rover;
static int equilibrium;
@@ -556,7 +578,7 @@
int i, k;
for (i = rt_hash_mask, k = rover; i >= 0; i--) {
- unsigned tmo = expire;
+ unsigned long tmo = expire;
k = (k + 1) & rt_hash_mask;
rthp = &rt_hash_table[k].chain;
@@ -602,7 +624,7 @@
if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
goto out;
- } while (!in_softirq() && jiffies - now < 1);
+ } while (!in_softirq() && time_before_eq(jiffies, now));
if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
goto out;
@@ -626,10 +648,19 @@
static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
{
struct rtable *rth, **rthp;
- unsigned long now = jiffies;
+ unsigned long now;
+ struct rtable *cand, **candp;
+ u32 min_score;
+ int chain_length;
int attempts = !in_softirq();
restart:
+ chain_length = 0;
+ min_score = ~(u32)0;
+ cand = NULL;
+ candp = NULL;
+ now = jiffies;
+
rthp = &rt_hash_table[hash].chain;
write_lock_bh(&rt_hash_table[hash].lock);
@@ -650,9 +681,35 @@
return 0;
}
+ if (!atomic_read(&rth->u.dst.__refcnt)) {
+ u32 score = rt_score(rth);
+
+ if (score <= min_score) {
+ cand = rth;
+ candp = rthp;
+ min_score = score;
+ }
+ }
+
+ chain_length++;
+
rthp = &rth->u.rt_next;
}
+ if (cand) {
+ /* ip_rt_gc_elasticity used to be average length of chain
+ * length, when exceeded gc becomes really aggressive.
+ *
+ * The second limit is less certain. At the moment it allows
+ * only 2 entries per bucket. We will see.
+ */
+ if (chain_length > ip_rt_gc_elasticity ||
+ (chain_length > 1 && !(min_score & (1<<31)))) {
+ *candp = cand->u.rt_next;
+ rt_free(cand);
+ }
+ }
+
/* Try to bind route to arp only if it is output
route or unicast forwarding path.
*/
@@ -960,7 +1017,7 @@
/* No redirected packets during ip_rt_redirect_silence;
* reset the algorithm.
*/
- if (jiffies - rt->u.dst.rate_last > ip_rt_redirect_silence)
+ if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
rt->u.dst.rate_tokens = 0;
/* Too many ignored redirects; do not send anything
@@ -974,8 +1031,9 @@
/* Check for load limit; set rate_last to the latest sent
* redirect.
*/
- if (jiffies - rt->u.dst.rate_last >
- (ip_rt_redirect_load << rt->u.dst.rate_tokens)) {
+ if (time_after(jiffies,
+ (rt->u.dst.rate_last +
+ (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
rt->u.dst.rate_last = jiffies;
++rt->u.dst.rate_tokens;
@@ -1672,6 +1730,7 @@
skb->dst = (struct dst_entry*)rth;
return 0;
}
+ rt_cache_stat[smp_processor_id()].in_hlist_search++;
}
read_unlock(&rt_hash_table[hash].lock);
@@ -2032,6 +2091,7 @@
*rp = rth;
return 0;
}
+ rt_cache_stat[smp_processor_id()].out_hlist_search++;
}
read_unlock_bh(&rt_hash_table[hash].lock);
-
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