net: neigh: use kfree_skb_reason() for __neigh_event_send()

Replace kfree_skb() used in __neigh_event_send() with
kfree_skb_reason(). Following drop reasons are added:

SKB_DROP_REASON_NEIGH_FAILED
SKB_DROP_REASON_NEIGH_QUEUEFULL
SKB_DROP_REASON_NEIGH_DEAD

The first two reasons above should be the hot path that skb drops
in neighbour subsystem.

Reviewed-by: Mengen Sun <mengensun@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 62b4bed..d67941f 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -389,6 +389,11 @@ enum skb_drop_reason {
        SKB_DROP_REASON_NEIGH_CREATEFAIL,       /* failed to create neigh
                                                 * entry
                                                 */
+       SKB_DROP_REASON_NEIGH_FAILED,   /* neigh entry in failed state */
+       SKB_DROP_REASON_NEIGH_QUEUEFULL,        /* arp_queue for neigh
+                                                * entry is full
+                                                */
+       SKB_DROP_REASON_NEIGH_DEAD,     /* neigh entry is dead */
        SKB_DROP_REASON_MAX,
 };
 

diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index 97f8097..1977f30 100644 (file)
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -42,6 +42,9 @@
           BPF_CGROUP_EGRESS)                                   \
        EM(SKB_DROP_REASON_IPV6DISABLED, IPV6DISABLED)          \
        EM(SKB_DROP_REASON_NEIGH_CREATEFAIL, NEIGH_CREATEFAIL)  \
+       EM(SKB_DROP_REASON_NEIGH_FAILED, NEIGH_FAILED)          \
+       EM(SKB_DROP_REASON_NEIGH_QUEUEFULL, NEIGH_QUEUEFULL)    \
+       EM(SKB_DROP_REASON_NEIGH_DEAD, NEIGH_DEAD)              \
        EMe(SKB_DROP_REASON_MAX, MAX)
 
 #undef EM

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index ec0bf73..f64ebd0 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1171,7 +1171,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb,
                        neigh->updated = jiffies;
                        write_unlock_bh(&neigh->lock);
 
-                       kfree_skb(skb);
+                       kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_FAILED);
                        return 1;
                }
        } else if (neigh->nud_state & NUD_STALE) {
@@ -1193,7 +1193,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb,
                                if (!buff)
                                        break;
                                neigh->arp_queue_len_bytes -= buff->truesize;
-                               kfree_skb(buff);
+                               kfree_skb_reason(buff, SKB_DROP_REASON_NEIGH_QUEUEFULL);
                                NEIGH_CACHE_STAT_INC(neigh->tbl, unres_discards);
                        }
                        skb_dst_force(skb);
@@ -1215,7 +1215,7 @@ out_dead:
        if (neigh->nud_state & NUD_STALE)
                goto out_unlock_bh;
        write_unlock_bh(&neigh->lock);
-       kfree_skb(skb);
+       kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_DEAD);
        trace_neigh_event_send_dead(neigh, 1);
        return 1;
 }