taglinefilesource code
acked67include/linux/skbuff.hvolatile char     acked,
acked515net/inet/skbuff.cn->acked=skb->acked;
acked3180net/inet/tcp.cif ((!dup_dumped && (skb1 == NULL || skb1->acked)) || before(th->seq, sk->acked_seq+1)) 
acked3194net/inet/tcp.cskb->acked = 1;
acked3222net/inet/tcp.cskb2->acked = 1;
acked3270net/inet/tcp.cif (!skb->acked) 
acked3293net/inet/tcp.cif (skb1->acked) 
acked3759net/inet/tcp.cif(skb==NULL || sk->receive_queue.prev->acked)
acked3833net/inet/tcp.cskb->acked = 0;
acked3920net/inet/tcp.cskb->acked=1;        /* Guaranteed true */