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: Jia He <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/sctp/proc.c

···
 /* 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;
 }