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authorEric Dumazet <edumazet@google.com>2021-01-28 19:21:45 +0300
committerJakub Kicinski <kuba@kernel.org>2021-01-30 07:59:53 +0300
commit0d6cd689f9ba47deffffe9dfd204843ce8f1a51e (patch)
tree3e5c70083f679eb9054fa4f4d8ff2aa026ea278b /net/ipv4
parentdf610cd9163b90adc3b5c23868089a0349580551 (diff)
downloadlinux-0d6cd689f9ba47deffffe9dfd204843ce8f1a51e.tar.xz
net: proc: speedup /proc/net/netstat
Use cache friendly helpers to better use cpu caches while reading /proc/net/netstat Tested on a platform with 256 threads (AMD Rome) Before: 305 usec spent in netstat_seq_show() After: 130 usec spent in netstat_seq_show() Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20210128162145.1703601-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/proc.c50
1 files changed, 36 insertions, 14 deletions
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 63cd370ea29d..6d46297a99f8 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -464,30 +464,52 @@ static int snmp_seq_show(struct seq_file *seq, void *v)
*/
static int netstat_seq_show(struct seq_file *seq, void *v)
{
- int i;
+ const int ip_cnt = ARRAY_SIZE(snmp4_ipextstats_list) - 1;
+ const int tcp_cnt = ARRAY_SIZE(snmp4_net_list) - 1;
struct net *net = seq->private;
+ unsigned long *buff;
+ int i;
seq_puts(seq, "TcpExt:");
- for (i = 0; snmp4_net_list[i].name; i++)
+ for (i = 0; i < tcp_cnt; i++)
seq_printf(seq, " %s", snmp4_net_list[i].name);
seq_puts(seq, "\nTcpExt:");
- for (i = 0; snmp4_net_list[i].name; i++)
- seq_printf(seq, " %lu",
- snmp_fold_field(net->mib.net_statistics,
- snmp4_net_list[i].entry));
-
+ buff = kzalloc(max(tcp_cnt * sizeof(long), ip_cnt * sizeof(u64)),
+ GFP_KERNEL);
+ if (buff) {
+ snmp_get_cpu_field_batch(buff, snmp4_net_list,
+ net->mib.net_statistics);
+ for (i = 0; i < tcp_cnt; i++)
+ seq_printf(seq, " %lu", buff[i]);
+ } else {
+ for (i = 0; i < tcp_cnt; i++)
+ seq_printf(seq, " %lu",
+ snmp_fold_field(net->mib.net_statistics,
+ snmp4_net_list[i].entry));
+ }
seq_puts(seq, "\nIpExt:");
- for (i = 0; snmp4_ipextstats_list[i].name; i++)
+ for (i = 0; i < ip_cnt; i++)
seq_printf(seq, " %s", snmp4_ipextstats_list[i].name);
seq_puts(seq, "\nIpExt:");
- for (i = 0; snmp4_ipextstats_list[i].name; i++)
- seq_printf(seq, " %llu",
- snmp_fold_field64(net->mib.ip_statistics,
- snmp4_ipextstats_list[i].entry,
- offsetof(struct ipstats_mib, syncp)));
-
+ if (buff) {
+ u64 *buff64 = (u64 *)buff;
+
+ memset(buff64, 0, ip_cnt * sizeof(u64));
+ snmp_get_cpu_field64_batch(buff64, snmp4_ipextstats_list,
+ net->mib.ip_statistics,
+ offsetof(struct ipstats_mib, syncp));
+ for (i = 0; i < ip_cnt; i++)
+ seq_printf(seq, " %llu", buff64[i]);
+ } else {
+ for (i = 0; i < ip_cnt; i++)
+ seq_printf(seq, " %llu",
+ snmp_fold_field64(net->mib.ip_statistics,
+ snmp4_ipextstats_list[i].entry,
+ offsetof(struct ipstats_mib, syncp)));
+ }
+ kfree(buff);
seq_putc(seq, '\n');
mptcp_seq_show(seq);
return 0;