[PATCH v4 3/7] proc: Reduce cache miss in snmp6_seq_show
From: Jia He <hidden>
Date: 2016-09-26 08:14:33
Also in:
linux-sctp, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted>
---
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..e047701 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]; + + 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)); } }
@@ -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)
--
2.5.5