[PATCH net-next 2/3] sched: act: ife: migrate to use per-cpu counters

[Alexander Aring]

This patch migrates the current counter handling which is protected by a
spinlock to a per-cpu counter handling. This reduce the time where the
spinlock is being held.

Signed-off-by: Alexander Aring <ar...@mojatatu.com>
---
 net/sched/act_ife.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index efac8a32c30a..f0d86b182387 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -463,7 +463,7 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
 
        if (!exists) {
                ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
-                                    bind, false);
+                                    bind, true);
                if (ret)
                        return ret;
                ret = ACT_P_CREATED;
@@ -624,19 +624,15 @@ static int tcf_ife_decode(struct sk_buff *skb, const 
struct tc_action *a,
        u8 *tlv_data;
        u16 metalen;
 
-       spin_lock(&ife->tcf_lock);
-       bstats_update(&ife->tcf_bstats, skb);
+       bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
        tcf_lastuse_update(&ife->tcf_tm);
-       spin_unlock(&ife->tcf_lock);
 
        if (skb_at_tc_ingress(skb))
                skb_push(skb, skb->dev->hard_header_len);
 
        tlv_data = ife_decode(skb, &metalen);
        if (unlikely(!tlv_data)) {
-               spin_lock(&ife->tcf_lock);
-               ife->tcf_qstats.drops++;
-               spin_unlock(&ife->tcf_lock);
+               qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
                return TC_ACT_SHOT;
        }
 
@@ -654,14 +650,12 @@ static int tcf_ife_decode(struct sk_buff *skb, const 
struct tc_action *a,
                         */
                        pr_info_ratelimited("Unknown metaid %d dlen %d\n",
                                            mtype, dlen);
-                       ife->tcf_qstats.overlimits++;
+                       
qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
                }
        }
 
        if (WARN_ON(tlv_data != ifehdr_end)) {
-               spin_lock(&ife->tcf_lock);
-               ife->tcf_qstats.drops++;
-               spin_unlock(&ife->tcf_lock);
+               qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
                return TC_ACT_SHOT;
        }
 
@@ -713,23 +707,20 @@ static int tcf_ife_encode(struct sk_buff *skb, const 
struct tc_action *a,
                        exceed_mtu = true;
        }
 
-       spin_lock(&ife->tcf_lock);
-       bstats_update(&ife->tcf_bstats, skb);
+       bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
        tcf_lastuse_update(&ife->tcf_tm);
 
        if (!metalen) {         /* no metadata to send */
                /* abuse overlimits to count when we allow packet
                 * with no metadata
                 */
-               ife->tcf_qstats.overlimits++;
-               spin_unlock(&ife->tcf_lock);
+               qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
                return action;
        }
        /* could be stupid policy setup or mtu config
         * so lets be conservative.. */
        if ((action == TC_ACT_SHOT) || exceed_mtu) {
-               ife->tcf_qstats.drops++;
-               spin_unlock(&ife->tcf_lock);
+               qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
                return TC_ACT_SHOT;
        }
 
@@ -738,6 +729,8 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct 
tc_action *a,
 
        ife_meta = ife_encode(skb, metalen);
 
+       spin_lock(&ife->tcf_lock);
+
        /* XXX: we dont have a clever way of telling encode to
         * not repeat some of the computations that are done by
         * ops->presence_check...
@@ -749,8 +742,8 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct 
tc_action *a,
                }
                if (err < 0) {
                        /* too corrupt to keep around if overwritten */
-                       ife->tcf_qstats.drops++;
                        spin_unlock(&ife->tcf_lock);
+                       qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
                        return TC_ACT_SHOT;
                }
                skboff += err;
-- 
2.11.0