[RFC PATCH v3 3/7] proc: Reduce cache miss in snmp6_seq_show
From: Jia He
Date: Fri Sep 09 2016 - 02:34:36 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.
Signed-off-by: Jia He <hejianet@xxxxxxxxx>
---
net/ipv6/proc.c | 32 +++++++++++++++++++++++---------
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 679253d0..50ba2c3 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;
@@ -192,13 +197,19 @@ static void snmp6_seq_show_item(struct seq_file *seq, void __percpu *pcpumib,
const struct snmp_mib *itemlist)
{
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);
+ unsigned long buff[SNMP_MIB_MAX];
+
+ memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+ if (pcpumib) {
+ 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));
}
}
@@ -206,10 +217,13 @@ static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
const struct snmp_mib *itemlist, size_t syncpoff)
{
int i;
+ u64 buff64[SNMP_MIB_MAX];
+
+ 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)
--
1.8.3.1