From f22d5c490990ecb6f4eb70c4ed478fc8cea78fe1 Mon Sep 17 00:00:00 2001 From: Jia He Date: Fri, 30 Sep 2016 11:28:59 +0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv4/proc.c | 70 ++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 47 insertions(+), 23 deletions(-) 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 #include +#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX) + /* * Report socket allocation statistics [mea@utu.fi] */ @@ -379,13 +381,15 @@ 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; struct net *net = seq->private; + u64 buff64[IPSTATS_MIB_MAX]; + int i; - 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); @@ -394,57 +398,77 @@ 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) +{ + 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); -- 2.7.4