8 files changed, 100 insertions, 35 deletions

diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h
index d1ff9b7e99b8..1fa5306e3e23 100644
--- a/include/net/dst_ops.h
+++ b/include/net/dst_ops.h
@@ -1,6 +1,7 @@
 #ifndef _NET_DST_OPS_H
 #define _NET_DST_OPS_H
 #include <linux/types.h>
+#include <linux/percpu_counter.h>
 
 struct dst_entry;
 struct kmem_cachep;
@@ -22,7 +23,41 @@ struct dst_ops {
         void                    (*update_pmtu)(struct dst_entry *dst, u32 mtu);
         int                     (*local_out)(struct sk_buff *skb);
 
-        atomic_t                entries;
         struct kmem_cache       *kmem_cachep;
+
+        struct percpu_counter   pcpuc_entries ____cacheline_aligned_in_smp;
 };
+
+static inline int dst_entries_get_fast(struct dst_ops *dst)
+{
+        return percpu_counter_read_positive(&dst->pcpuc_entries);
+}
+
+static inline int dst_entries_get_slow(struct dst_ops *dst)
+{
+        int res;
+
+        local_bh_disable();
+        res = percpu_counter_sum_positive(&dst->pcpuc_entries);
+        local_bh_enable();
+        return res;
+}
+
+static inline void dst_entries_add(struct dst_ops *dst, int val)
+{
+        local_bh_disable();
+        percpu_counter_add(&dst->pcpuc_entries, val);
+        local_bh_enable();
+}
+
+static inline int dst_entries_init(struct dst_ops *dst)
+{
+        return percpu_counter_init(&dst->pcpuc_entries, 0);
+}
+
+static inline void dst_entries_destroy(struct dst_ops *dst)
+{
+        percpu_counter_destroy(&dst->pcpuc_entries);
+}
+
 #endif
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 77f7b5fda45a..7f9ce9600ef3 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -106,7 +106,6 @@ static struct dst_ops fake_dst_ops = {
         .family =               AF_INET,
         .protocol =             cpu_to_be16(ETH_P_IP),
         .update_pmtu =          fake_update_pmtu,
-        .entries =              ATOMIC_INIT(0),
 };
 
 /*
@@ -1003,15 +1002,22 @@ int __init br_netfilter_init(void)
 {
         int ret;
 
-        ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
+        ret = dst_entries_init(&fake_dst_ops);
         if (ret < 0)
                 return ret;
+
+        ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
+        if (ret < 0) {
+                dst_entries_destroy(&fake_dst_ops);
+                return ret;
+        }
 #ifdef CONFIG_SYSCTL
         brnf_sysctl_header = register_sysctl_paths(brnf_path, brnf_table);
         if (brnf_sysctl_header == NULL) {
                 printk(KERN_WARNING
                        "br_netfilter: can't register to sysctl.\n");
                 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
+                dst_entries_destroy(&fake_dst_ops);
                 return -ENOMEM;
         }
 #endif
@@ -1025,4 +1031,5 @@ void br_netfilter_fini(void)
 #ifdef CONFIG_SYSCTL
         unregister_sysctl_table(brnf_sysctl_header);
 #endif
+        dst_entries_destroy(&fake_dst_ops);
 }
diff --git a/net/core/dst.c b/net/core/dst.c
index 978a1ee1f7d0..32e542d7f472 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -168,7 +168,7 @@ void *dst_alloc(struct dst_ops *ops)
 {
         struct dst_entry *dst;
 
-        if (ops->gc && atomic_read(&ops->entries) > ops->gc_thresh) {
+        if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) {
                 if (ops->gc(ops))
                         return NULL;
         }
@@ -183,7 +183,7 @@ void *dst_alloc(struct dst_ops *ops)
 #if RT_CACHE_DEBUG >= 2
         atomic_inc(&dst_total);
 #endif
-        atomic_inc(&ops->entries);
+        dst_entries_add(ops, 1);
         return dst;
 }
 EXPORT_SYMBOL(dst_alloc);
@@ -236,7 +236,7 @@ again:
                 neigh_release(neigh);
         }
 
-        atomic_dec(&dst->ops->entries);
+        dst_entries_add(dst->ops, -1);
 
         if (dst->ops->destroy)
                 dst->ops->destroy(dst);
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 6585ea6d1182..df0f3e54ff8a 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -132,7 +132,6 @@ static struct dst_ops dn_dst_ops = {
         .negative_advice =      dn_dst_negative_advice,
         .link_failure =         dn_dst_link_failure,
         .update_pmtu =          dn_dst_update_pmtu,
-        .entries =              ATOMIC_INIT(0),
 };
 
 static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
@@ -1758,6 +1757,7 @@ void __init dn_route_init(void)
         dn_dst_ops.kmem_cachep =
                 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+        dst_entries_init(&dn_dst_ops);
         setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
         dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
         add_timer(&dn_route_timer);
@@ -1816,5 +1816,6 @@ void __exit dn_route_cleanup(void)
         dn_run_flush(0);
 
         proc_net_remove(&init_net, "decnet_cache");
+        dst_entries_destroy(&dn_dst_ops);
 }
 
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 3888f6ba0a5c..0755aa4af86c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -159,7 +159,6 @@ static struct dst_ops ipv4_dst_ops = {
         .link_failure =         ipv4_link_failure,
         .update_pmtu =          ip_rt_update_pmtu,
         .local_out =            __ip_local_out,
-        .entries =              ATOMIC_INIT(0),
 };
 
 #define ECN_OR_COST(class)      TC_PRIO_##class
@@ -466,7 +465,7 @@ static int rt_cpu_seq_show(struct seq_file *seq, void *v)
 
         seq_printf(seq,"%08x  %08x %08x %08x %08x %08x %08x %08x "
                    " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
-                   atomic_read(&ipv4_dst_ops.entries),
+                   dst_entries_get_slow(&ipv4_dst_ops),
                    st->in_hit,
                    st->in_slow_tot,
                    st->in_slow_mc,
@@ -945,6 +944,7 @@ static int rt_garbage_collect(struct dst_ops *ops)
         struct rtable *rth, **rthp;
         unsigned long now = jiffies;
         int goal;
+        int entries = dst_entries_get_fast(&ipv4_dst_ops);
 
         /*
          * Garbage collection is pretty expensive,
@@ -954,28 +954,28 @@ static int rt_garbage_collect(struct dst_ops *ops)
         RT_CACHE_STAT_INC(gc_total);
 
         if (now - last_gc < ip_rt_gc_min_interval &&
-            atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
+            entries < ip_rt_max_size) {
                 RT_CACHE_STAT_INC(gc_ignored);
                 goto out;
         }
 
+        entries = dst_entries_get_slow(&ipv4_dst_ops);
         /* Calculate number of entries, which we want to expire now. */
-        goal = atomic_read(&ipv4_dst_ops.entries) -
-                (ip_rt_gc_elasticity << rt_hash_log);
+        goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
         if (goal <= 0) {
                 if (equilibrium < ipv4_dst_ops.gc_thresh)
                         equilibrium = ipv4_dst_ops.gc_thresh;
-                goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
+                goal = entries - equilibrium;
                 if (goal > 0) {
                         equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
-                        goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
+                        goal = entries - equilibrium;
                 }
         } else {
                 /* We are in dangerous area. Try to reduce cache really
                  * aggressively.
                  */
                 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
-                equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
+                equilibrium = entries - goal;
         }
 
         if (now - last_gc >= ip_rt_gc_min_interval)
@@ -1032,14 +1032,16 @@ static int rt_garbage_collect(struct dst_ops *ops)
                 expire >>= 1;
 #if RT_CACHE_DEBUG >= 2
                 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
-                                atomic_read(&ipv4_dst_ops.entries), goal, i);
+                                dst_entries_get_fast(&ipv4_dst_ops), goal, i);
 #endif
 
-                if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
+                if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
                         goto out;
         } while (!in_softirq() && time_before_eq(jiffies, now));
 
-        if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
+        if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
+                goto out;
+        if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
                 goto out;
         if (net_ratelimit())
                 printk(KERN_WARNING "dst cache overflow\n");
@@ -1049,11 +1051,12 @@ static int rt_garbage_collect(struct dst_ops *ops)
 work_done:
         expire += ip_rt_gc_min_interval;
         if (expire > ip_rt_gc_timeout ||
-            atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
+            dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
+            dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
                 expire = ip_rt_gc_timeout;
 #if RT_CACHE_DEBUG >= 2
         printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
-                        atomic_read(&ipv4_dst_ops.entries), goal, rover);
+                        dst_entries_get_fast(&ipv4_dst_ops), goal, rover);
 #endif
 out:    return 0;
 }
@@ -2717,7 +2720,6 @@ static struct dst_ops ipv4_dst_blackhole_ops = {
         .destroy                =       ipv4_dst_destroy,
         .check                  =       ipv4_blackhole_dst_check,
         .update_pmtu            =       ipv4_rt_blackhole_update_pmtu,
-        .entries                =       ATOMIC_INIT(0),
 };
 
 
@@ -3287,6 +3289,12 @@ int __init ip_rt_init(void)
 
         ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
 
+        if (dst_entries_init(&ipv4_dst_ops) < 0)
+                panic("IP: failed to allocate ipv4_dst_ops counter\n");
+
+        if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
+                panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
+
         rt_hash_table = (struct rt_hash_bucket *)
                 alloc_large_system_hash("IP route cache",
                                         sizeof(struct rt_hash_bucket),
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index a580349f0b8a..4464f3bff6a7 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -174,7 +174,7 @@ static inline int xfrm4_garbage_collect(struct dst_ops *ops)
         struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);
 
         xfrm4_policy_afinfo.garbage_collect(net);
-        return (atomic_read(&ops->entries) > ops->gc_thresh * 2);
+        return (dst_entries_get_slow(ops) > ops->gc_thresh * 2);
 }
 
 static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -232,7 +232,6 @@ static struct dst_ops xfrm4_dst_ops = {
         .ifdown =               xfrm4_dst_ifdown,
         .local_out =            __ip_local_out,
         .gc_thresh =            1024,
-        .entries =              ATOMIC_INIT(0),
 };
 
 static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
@@ -288,6 +287,7 @@ void __init xfrm4_init(int rt_max_size)
          * and start cleaning when were 1/2 full
          */
         xfrm4_dst_ops.gc_thresh = rt_max_size/2;
+        dst_entries_init(&xfrm4_dst_ops);
 
         xfrm4_state_init();
         xfrm4_policy_init();
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 17e217933885..25661f968f3f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -109,7 +109,6 @@ static struct dst_ops ip6_dst_ops_template = {
         .link_failure           =       ip6_link_failure,
         .update_pmtu            =       ip6_rt_update_pmtu,
         .local_out              =       __ip6_local_out,
-        .entries                =       ATOMIC_INIT(0),
 };
 
 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -122,7 +121,6 @@ static struct dst_ops ip6_dst_blackhole_ops = {
         .destroy                =       ip6_dst_destroy,
         .check                  =       ip6_dst_check,
         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
-        .entries                =       ATOMIC_INIT(0),
 };
 
 static struct rt6_info ip6_null_entry_template = {
@@ -1058,19 +1056,22 @@ static int ip6_dst_gc(struct dst_ops *ops)
         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
+        int entries;
 
+        entries = dst_entries_get_fast(ops);
         if (time_after(rt_last_gc + rt_min_interval, now) &&
-            atomic_read(&ops->entries) <= rt_max_size)
+            entries <= rt_max_size)
                 goto out;
 
         net->ipv6.ip6_rt_gc_expire++;
         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net);
         net->ipv6.ip6_rt_last_gc = now;
-        if (atomic_read(&ops->entries) < ops->gc_thresh)
+        entries = dst_entries_get_slow(ops);
+        if (entries < ops->gc_thresh)
                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
 out:
         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
-        return atomic_read(&ops->entries) > rt_max_size;
+        return entries > rt_max_size;
 }
 
 /* Clean host part of a prefix. Not necessary in radix tree,
@@ -2524,7 +2525,7 @@ static int rt6_stats_seq_show(struct seq_file *seq, void *v)
                    net->ipv6.rt6_stats->fib_rt_alloc,
                    net->ipv6.rt6_stats->fib_rt_entries,
                    net->ipv6.rt6_stats->fib_rt_cache,
-                   atomic_read(&net->ipv6.ip6_dst_ops.entries),
+                   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
                    net->ipv6.rt6_stats->fib_discarded_routes);
 
         return 0;
@@ -2666,11 +2667,14 @@ static int __net_init ip6_route_net_init(struct net *net)
         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
                sizeof(net->ipv6.ip6_dst_ops));
 
+        if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
+                goto out_ip6_dst_ops;
+
         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
                                            sizeof(*net->ipv6.ip6_null_entry),
                                            GFP_KERNEL);
         if (!net->ipv6.ip6_null_entry)
-                goto out_ip6_dst_ops;
+                goto out_ip6_dst_entries;
         net->ipv6.ip6_null_entry->dst.path =
                 (struct dst_entry *)net->ipv6.ip6_null_entry;
         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
@@ -2720,6 +2724,8 @@ out_ip6_prohibit_entry:
 out_ip6_null_entry:
         kfree(net->ipv6.ip6_null_entry);
 #endif
+out_ip6_dst_entries:
+        dst_entries_destroy(&net->ipv6.ip6_dst_ops);
 out_ip6_dst_ops:
         goto out;
 }
@@ -2758,10 +2764,14 @@ int __init ip6_route_init(void)
         if (!ip6_dst_ops_template.kmem_cachep)
                 goto out;
 
-        ret = register_pernet_subsys(&ip6_route_net_ops);
+        ret = dst_entries_init(&ip6_dst_blackhole_ops);
         if (ret)
                 goto out_kmem_cache;
 
+        ret = register_pernet_subsys(&ip6_route_net_ops);
+        if (ret)
+                goto out_dst_entries;
+
         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
 
         /* Registering of the loopback is done before this portion of code,
@@ -2808,6 +2818,8 @@ out_fib6_init:
         fib6_gc_cleanup();
 out_register_subsys:
         unregister_pernet_subsys(&ip6_route_net_ops);
+out_dst_entries:
+        dst_entries_destroy(&ip6_dst_blackhole_ops);
 out_kmem_cache:
         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
         goto out;
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 39676eac3a37..7e74023ea6e4 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -199,7 +199,7 @@ static inline int xfrm6_garbage_collect(struct dst_ops *ops)
         struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);
 
         xfrm6_policy_afinfo.garbage_collect(net);
-        return atomic_read(&ops->entries) > ops->gc_thresh * 2;
+        return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
 }
 
 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
@@ -255,7 +255,6 @@ static struct dst_ops xfrm6_dst_ops = {
         .ifdown =               xfrm6_dst_ifdown,
         .local_out =            __ip6_local_out,
         .gc_thresh =            1024,
-        .entries =              ATOMIC_INIT(0),
 };
 
 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
@@ -312,11 +311,13 @@ int __init xfrm6_init(void)
          */
         gc_thresh = FIB6_TABLE_HASHSZ * 8;
         xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh;
+        dst_entries_init(&xfrm6_dst_ops);
 
         ret = xfrm6_policy_init();
-        if (ret)
+        if (ret) {
+                dst_entries_destroy(&xfrm6_dst_ops);
                 goto out;
-
+        }
         ret = xfrm6_state_init();
         if (ret)
                 goto out_policy;
@@ -341,4 +342,5 @@ void xfrm6_fini(void)
         //xfrm6_input_fini();
         xfrm6_policy_fini();
         xfrm6_state_fini();
+        dst_entries_destroy(&xfrm6_dst_ops);
 }