Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1471947 > unrolled thread

[RFC PATCH 4/6] proc: Reduce cache miss in xfrm_statistics_seq_show

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [RFC PATCH 4/6] proc: Reduce cache miss in xfrm_statistics_seq_show Jia He <hejianet@gmail.com> - 2016-08-29 18:10 +0200

#1471947 — [RFC PATCH 4/6] proc: Reduce cache miss in xfrm_statistics_seq_show

This patch exchanges the two loop for collecting the percpu
statistics data. This can reduce cache misses by going through
all the items of each cpu sequentially.

Signed-off-by: Jia He <hejianet@gmail.com>
---
 net/xfrm/xfrm_proc.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c
index 9c4fbd8..c9df546 100644
--- a/net/xfrm/xfrm_proc.c
+++ b/net/xfrm/xfrm_proc.c
@@ -51,11 +51,20 @@ static const struct snmp_mib xfrm_mib_list[] = {
 static int xfrm_statistics_seq_show(struct seq_file *seq, void *v)
 {
 	struct net *net = seq->private;
-	int i;
-	for (i = 0; xfrm_mib_list[i].name; i++)
+	int i, c;
+	unsigned long buff[LINUX_MIB_XFRMMAX];
+
+	memset(buff, 0, sizeof(unsigned long) * LINUX_MIB_XFRMMAX);
+
+	for_each_possible_cpu(c)
+		for (i = 0; xfrm_mib_list[i].name != NULL; i++)
+			buff[i] += snmp_get_cpu_field(
+						net->mib.xfrm_statistics,
+						c, xfrm_mib_list[i].entry);
+	for (i = 0; xfrm_mib_list[i].name != NULL; i++)
 		seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
-			   snmp_fold_field(net->mib.xfrm_statistics,
-					   xfrm_mib_list[i].entry));
+						buff[i]);
+
 	return 0;
 }
 
-- 
1.8.3.1

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web