proc: Reduce cache miss in sctp_snmp_seq_show

This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Signed-off-by: NJia He <hejianet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/proc.c

@@ -73,13 +73,17 @@ static const struct snmp_mib sctp_snmp_list[] = {
 /* Display sctp snmp mib statistics(/proc/net/sctp/snmp). */
 static int sctp_snmp_seq_show(struct seq_file *seq, void *v)
 {
+	unsigned long buff[SCTP_MIB_MAX];
 	struct net *net = seq->private;
 	int i;
 
+	memset(buff, 0, sizeof(unsigned long) * SCTP_MIB_MAX);
+
+	snmp_get_cpu_field_batch(buff, sctp_snmp_list,
+				 net->sctp.sctp_statistics);
 	for (i = 0; sctp_snmp_list[i].name != NULL; i++)
 		seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
-			   snmp_fold_field(net->sctp.sctp_statistics,
-				      sctp_snmp_list[i].entry));
+						buff[i]);
 
 	return 0;
 }