[PATCH net-next 1/2] net sched act_vlan: Change stats update to use per-core stats

From: Manish Kurup
Date: Tue Oct 10 2017 - 22:32:43 EST


The VLAN action maintains one set of stats across all cores, and uses a
spinlock to synchronize updates to it from the same. Changed this to use a
per-CPU stats context instead.
This change will result in better performance.

Signed-off-by: Manish Kurup <manish.kurup@xxxxxxxxxxx>
---
net/sched/act_vlan.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
index 16eb067..14c262c 100644
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -30,9 +30,10 @@ static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,
int err;
u16 tci;

- spin_lock(&v->tcf_lock);
tcf_lastuse_update(&v->tcf_tm);
- bstats_update(&v->tcf_bstats, skb);
+ bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
+
+ spin_lock(&v->tcf_lock);
action = v->tcf_action;

/* Ensure 'data' points at mac_header prior calling vlan manipulating
@@ -85,7 +86,8 @@ static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,

drop:
action = TC_ACT_SHOT;
- v->tcf_qstats.drops++;
+ qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
+
unlock:
if (skb_at_tc_ingress(skb))
skb_pull_rcsum(skb, skb->mac_len);
@@ -172,7 +174,7 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla,

if (!exists) {
ret = tcf_idr_create(tn, parm->index, est, a,
- &act_vlan_ops, bind, false);
+ &act_vlan_ops, bind, true);
if (ret)
return ret;

--
2.7.4