proc: Reduce cache miss in 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.
Then snmp_seq_show is split into 2 parts to avoid build warning "the frame
size" larger than 1024.
Signed-off-by: Jia He <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 1ed015e..f51fc88 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -46,6 +46,8 @@
#include <net/sock.h>
#include <net/raw.h>
+#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+
/*
* Report socket allocation statistics [mea@utu.fi]
*/
@@ -379,13 +381,15 @@
/*
* Called from the PROCfs module. This outputs /proc/net/snmp.
*/
-static int snmp_seq_show(struct seq_file *seq, void *v)
+static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
- int i;
struct net *net = seq->private;
+ u64 buff64[IPSTATS_MIB_MAX];
+ int i;
+
+ memset(buff64, 0, IPSTATS_MIB_MAX * sizeof(u64));
seq_puts(seq, "Ip: Forwarding DefaultTTL");
-
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
@@ -394,57 +398,77 @@
net->ipv4.sysctl_ip_default_ttl);
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
- snmp4_ipstats_list[i].entry,
- offsetof(struct ipstats_mib, syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
- icmp_put(seq); /* RFC 2011 compatibility */
- icmpmsg_put(seq);
+ return 0;
+}
+
+static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
+{
+ unsigned long buff[TCPUDP_MIB_MAX];
+ struct net *net = seq->private;
+ int i;
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
seq_puts(seq, "\nTcp:");
for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_tcp_list[i].name);
seq_puts(seq, "\nTcp:");
+ snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
+ net->mib.tcp_statistics);
for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
/* MaxConn field is signed, RFC 2012 */
if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
- seq_printf(seq, " %ld",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %ld", buff[i]);
else
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.tcp_statistics,
- snmp4_tcp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
}
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
+
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+ net->mib.udp_statistics);
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdp:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udp_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));
/* the UDP and UDP-Lite MIBs are the same */
seq_puts(seq, "\nUdpLite:");
+ snmp_get_cpu_field_batch(buff, snmp4_udp_list,
+ net->mib.udplite_statistics);
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_udp_list[i].name);
-
seq_puts(seq, "\nUdpLite:");
for (i = 0; snmp4_udp_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.udplite_statistics,
- snmp4_udp_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
seq_putc(seq, '\n');
return 0;
}
+static int snmp_seq_show(struct seq_file *seq, void *v)
+{
+ snmp_seq_show_ipstats(seq, v);
+
+ icmp_put(seq); /* RFC 2011 compatibility */
+ icmpmsg_put(seq);
+
+ snmp_seq_show_tcp_udp(seq, v);
+
+ return 0;
+}
+
static int snmp_seq_open(struct inode *inode, struct file *file)
{
return single_open_net(inode, file, snmp_seq_show);