ipv4: icmp: use percpu allocation

Get rid of nr_cpu_ids and use modern percpu allocation.

Note that the sockets themselves are not yet allocated
using NUMA affinity.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ipv4.h

@@ -48,7 +48,8 @@ struct netns_ipv4 {
 	struct hlist_head	*fib_table_hash;
 	struct sock		*fibnl;
 
-	struct sock		**icmp_sk;
+	struct sock  * __percpu	*icmp_sk;
+
 	struct inet_peer_base	*peers;
 	struct tcpm_hash_bucket	*tcp_metrics_hash;
 	unsigned int		tcp_metrics_hash_log;

net/ipv4/icmp.c

@@ -205,7 +205,7 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
  */
 static struct sock *icmp_sk(struct net *net)
 {
-	return net->ipv4.icmp_sk[smp_processor_id()];
+	return *this_cpu_ptr(net->ipv4.icmp_sk);
 }
 
 static inline struct sock *icmp_xmit_lock(struct net *net)
@@ -1140,18 +1140,17 @@ static void __net_exit icmp_sk_exit(struct net *net)
 	int i;
 
 	for_each_possible_cpu(i)
-		inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]);
-	kfree(net->ipv4.icmp_sk);
+		inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
+	free_percpu(net->ipv4.icmp_sk);
 	net->ipv4.icmp_sk = NULL;
 }
 
 static int __net_init icmp_sk_init(struct net *net)
 {
 	int i, err;
 
-	net->ipv4.icmp_sk =
-		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
-	if (net->ipv4.icmp_sk == NULL)
+	net->ipv4.icmp_sk = alloc_percpu(struct sock *);
+	if (!net->ipv4.icmp_sk)
 		return -ENOMEM;
 
 	for_each_possible_cpu(i) {
@@ -1162,7 +1161,7 @@ static int __net_init icmp_sk_init(struct net *net)
 		if (err < 0)
 			goto fail;
 
-		net->ipv4.icmp_sk[i] = sk;
+		*per_cpu_ptr(net->ipv4.icmp_sk, i) = sk;
 
 		/* Enough space for 2 64K ICMP packets, including
 		 * sk_buff/skb_shared_info struct overhead.
@@ -1203,8 +1202,8 @@ static int __net_init icmp_sk_init(struct net *net)
 
 fail:
 	for_each_possible_cpu(i)
-		inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]);
-	kfree(net->ipv4.icmp_sk);
+		inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
+	free_percpu(net->ipv4.icmp_sk);
 	return err;
 }