From 4a4857b1c81ef39a9dc719af6b498cd39d1c1eb0 Mon Sep 17 00:00:00 2001 From: Jia He Date: Fri, 30 Sep 2016 11:29:00 +0800 Subject: [PATCH] proc: Reduce cache miss in snmp6_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 Signed-off-by: David S. Miller --- net/ipv6/proc.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c index 679253d0af84..cc8e3ae9ca73 100644 --- a/net/ipv6/proc.c +++ b/net/ipv6/proc.c @@ -30,6 +30,11 @@ #include #include +#define MAX4(a, b, c, d) \ + max_t(u32, max_t(u32, a, b), max_t(u32, c, d)) +#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \ + IPSTATS_MIB_MAX, ICMP_MIB_MAX) + static int sockstat6_seq_show(struct seq_file *seq, void *v) { struct net *net = seq->private; @@ -191,25 +196,34 @@ static void snmp6_seq_show_item(struct seq_file *seq, void __percpu *pcpumib, atomic_long_t *smib, const struct snmp_mib *itemlist) { + unsigned long buff[SNMP_MIB_MAX]; int i; - unsigned long val; - for (i = 0; itemlist[i].name; i++) { - val = pcpumib ? - snmp_fold_field(pcpumib, itemlist[i].entry) : - atomic_long_read(smib + itemlist[i].entry); - seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, val); + if (pcpumib) { + memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX); + + snmp_get_cpu_field_batch(buff, itemlist, pcpumib); + for (i = 0; itemlist[i].name; i++) + seq_printf(seq, "%-32s\t%lu\n", + itemlist[i].name, buff[i]); + } else { + for (i = 0; itemlist[i].name; i++) + seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name, + atomic_long_read(smib + itemlist[i].entry)); } } static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib, const struct snmp_mib *itemlist, size_t syncpoff) { + u64 buff64[SNMP_MIB_MAX]; int i; + memset(buff64, 0, sizeof(unsigned long) * SNMP_MIB_MAX); + + snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff); for (i = 0; itemlist[i].name; i++) - seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, - snmp_fold_field64(mib, itemlist[i].entry, syncpoff)); + seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]); } static int snmp6_seq_show(struct seq_file *seq, void *v) -- 2.20.1