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 <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..cc8e3ae 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -30,6 +30,11 @@
#include <net/transp_v6.h>
#include <net/ipv6.h>
+#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 @@
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)