From: Eric Dumazet <eduma...@google.com>
sk_drops can be an often written field, do not read it unless
application showed interest.
Note that sk_drops can be read via inet_diag, so applications
can avoid getting this info from every received packet.
In the future, 'reading' sk_drops might require folding per node or per
cpu fields, and thus become even more expensive than today.
Signed-off-by: Eric Dumazet <eduma...@google.com>
Cc: Paolo Abeni <pab...@redhat.com>
---
include/net/sock.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index
1749e38d03014558ac882b5d1fb37b11ac5e6705..be167c1483f4a5a74b466f135bbfdf4281e5bef4
100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2160,7 +2160,8 @@ struct sock_skb_cb {
static inline void
sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
{
- SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops);
+ SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
+ atomic_read(&sk->sk_drops) : 0;
}
static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
