[RFC PATCH v3 2/7] proc: Reduce cache miss in {snmp,netstat}_seq_show
From: Jia He
Date: Fri Sep 09 2016 - 02:35:49 EST
This is to use the generic interface snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.
Then snmp_seq_show and netstat_seq_show are split into 2 parts to avoid build
warning "the frame size" larger than 1024 on s390.
Signed-off-by: Jia He <hejianet@xxxxxxxxx>
---
net/ipv4/proc.c | 106 +++++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 74 insertions(+), 32 deletions(-)
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 9f665b6..c6fc80e 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@xxxxxx]
*/
@@ -378,13 +380,15 @@ static void icmp_put(struct seq_file *seq)
/*
* 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;
+ u64 buff64[IPSTATS_MIB_MAX];
struct net *net = seq->private;
- seq_puts(seq, "Ip: Forwarding DefaultTTL");
+ 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);
@@ -393,57 +397,77 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
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)
+{
+ int i;
+ unsigned long buff[TCPUDP_MIB_MAX];
+ struct net *net = seq->private;
+
+ 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);
@@ -457,41 +481,59 @@ static const struct file_operations snmp_seq_fops = {
.release = single_release_net,
};
-
-
/*
* Output /proc/net/netstat
*/
-static int netstat_seq_show(struct seq_file *seq, void *v)
+static int netstat_seq_show_tcpext(struct seq_file *seq, void *v)
{
int i;
+ unsigned long buff[LINUX_MIB_MAX];
struct net *net = seq->private;
+ memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_MAX);
+
seq_puts(seq, "TcpExt:");
for (i = 0; snmp4_net_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_net_list[i].name);
seq_puts(seq, "\nTcpExt:");
+ snmp_get_cpu_field_batch(buff, snmp4_net_list,
+ net->mib.net_statistics);
for (i = 0; snmp4_net_list[i].name != NULL; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.net_statistics,
- snmp4_net_list[i].entry));
+ seq_printf(seq, " %lu", buff[i]);
+
+ return 0;
+}
+
+static int netstat_seq_show_ipext(struct seq_file *seq, void *v)
+{
+ int i;
+ u64 buff64[IPSTATS_MIB_MAX];
+ struct net *net = seq->private;
seq_puts(seq, "\nIpExt:");
for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++)
seq_printf(seq, " %s", snmp4_ipextstats_list[i].name);
seq_puts(seq, "\nIpExt:");
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipextstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
- snmp4_ipextstats_list[i].entry,
- offsetof(struct ipstats_mib, syncp)));
+ seq_printf(seq, " %llu", buff64[i]);
seq_putc(seq, '\n');
return 0;
}
+static int netstat_seq_show(struct seq_file *seq, void *v)
+{
+ netstat_seq_show_tcpext(seq, v);
+ netstat_seq_show_ipext(seq, v);
+
+ return 0;
+}
+
static int netstat_seq_open(struct inode *inode, struct file *file)
{
return single_open_net(inode, file, netstat_seq_show);
--
1.8.3.1