Merge tag 'rxrpc-next-20230208' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc development

Here are some miscellaneous changes for rxrpc:

(1) Use consume_skb() rather than kfree_skb_reason().

(2) Fix unnecessary waking when poking and already-poked call.

(3) Add ack.rwind to the rxrpc_tx_ack tracepoint as this indicates how
many incoming DATA packets we're telling the peer that we are
currently willing to accept on this call.

(4) Reduce duplicate ACK transmission. We send ACKs to let the peer know
that we're increasing the receive window (ack.rwind) as we consume
packets locally. Normal ACK transmission is triggered in three places
and that leads to duplicates being sent.
====================

Signed-off-by: David S. Miller <[e-mail]>

include/trace/events/rxrpc.h

···
 TRACE_EVENT(rxrpc_tx_ack,
 	    TP_PROTO(unsigned int call, rxrpc_serial_t serial,
 		     rxrpc_seq_t ack_first, rxrpc_serial_t ack_serial,
-		     u8 reason, u8 n_acks),
+		     u8 reason, u8 n_acks, u16 rwind),
 
-	    TP_ARGS(call, serial, ack_first, ack_serial, reason, n_acks),
+	    TP_ARGS(call, serial, ack_first, ack_serial, reason, n_acks, rwind),
 
 	    TP_STRUCT__entry(
 		    __field(unsigned int,	call)
···
 		    __field(rxrpc_serial_t,	ack_serial)
 		    __field(u8,			reason)
 		    __field(u8,			n_acks)
+		    __field(u16,		rwind)
 			     ),
 
 	    TP_fast_assign(
···
 		    __entry->ack_serial = ack_serial;
 		    __entry->reason = reason;
 		    __entry->n_acks = n_acks;
+		    __entry->rwind = rwind;
 			   ),
 
-	    TP_printk(" c=%08x ACK  %08x %s f=%08x r=%08x n=%u",
+	    TP_printk(" c=%08x ACK  %08x %s f=%08x r=%08x n=%u rw=%u",
 		      __entry->call,
 		      __entry->serial,
 		      __print_symbolic(__entry->reason, rxrpc_ack_names),
 		      __entry->ack_first,
 		      __entry->ack_serial,
-		      __entry->n_acks)
+		      __entry->n_acks,
+		      __entry->rwind)
 	    );
 
 TRACE_EVENT(rxrpc_receive,

net/rxrpc/call_object.c

···
 		spin_lock_bh(&local->lock);
 		busy = !list_empty(&call->attend_link);
 		trace_rxrpc_poke_call(call, busy, what);
+		if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke))
+			busy = true;
 		if (!busy) {
-			rxrpc_get_call(call, rxrpc_call_get_poke);
 			list_add_tail(&call->attend_link, &local->call_attend_q);
 		}
 		spin_unlock_bh(&local->lock);
-		rxrpc_wake_up_io_thread(local);
+		if (!busy)
+			rxrpc_wake_up_io_thread(local);
 	}
 }
 

net/rxrpc/conn_event.c

···
 		trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 				   ntohl(pkt.ack.firstPacket),
 				   ntohl(pkt.ack.serial),
-				   pkt.ack.reason, 0);
+				   pkt.ack.reason, 0, rxrpc_rx_window_size);
 		break;
 
 	default:

net/rxrpc/output.c

···
  */
 static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
 				 struct rxrpc_call *call,
-				 struct rxrpc_txbuf *txb)
+				 struct rxrpc_txbuf *txb,
+				 u16 *_rwind)
 {
 	struct rxrpc_ackinfo ackinfo;
 	unsigned int qsize, sack, wrap, to;
···
 	jmax = rxrpc_rx_jumbo_max;
 	qsize = (window - 1) - call->rx_consumed;
 	rsize = max_t(int, call->rx_winsize - qsize, 0);
+	*_rwind = rsize;
 	ackinfo.rxMTU		= htonl(rxrpc_rx_mtu);
 	ackinfo.maxMTU		= htonl(mtu);
 	ackinfo.rwind		= htonl(rsize);
···
 	rxrpc_serial_t serial;
 	size_t len, n;
 	int ret, rtt_slot = -1;
+	u16 rwind;
 
 	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 		return -ECONNRESET;
···
 	if (txb->ack.reason == RXRPC_ACK_PING)
 		txb->wire.flags |= RXRPC_REQUEST_ACK;
 
-	n = rxrpc_fill_out_ack(conn, call, txb);
+	n = rxrpc_fill_out_ack(conn, call, txb, &rwind);
 	if (n == 0)
 		return 0;
 
···
 	txb->wire.serial = htonl(serial);
 	trace_rxrpc_tx_ack(call->debug_id, serial,
 			   ntohl(txb->ack.firstPacket),
-			   ntohl(txb->ack.serial), txb->ack.reason, txb->ack.nAcks);
+			   ntohl(txb->ack.serial), txb->ack.reason, txb->ack.nAcks,
+			   rwind);
 
 	if (txb->ack.reason == RXRPC_ACK_PING)
 		rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping);

net/rxrpc/recvmsg.c

···
 	/* Check to see if there's an ACK that needs sending. */
 	acked = atomic_add_return(call->rx_consumed - old_consumed,
 				  &call->ackr_nr_consumed);
-	if (acked > 2 &&
+	if (acked > 8 &&
 	    !test_and_set_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags))
 		rxrpc_poke_call(call, rxrpc_call_poke_idle);
 }

net/rxrpc/skbuff.c

···
 	if (skb) {
 		int n = atomic_dec_return(select_skb_count(skb));
 		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
-		kfree_skb_reason(skb, SKB_CONSUMED);
+		consume_skb(skb);
 	}
 }
 
···
 		int n = atomic_dec_return(select_skb_count(skb));
 		trace_rxrpc_skb(skb, refcount_read(&skb->users), n,
 				rxrpc_skb_put_purge);
-		kfree_skb_reason(skb, SKB_CONSUMED);
+		consume_skb(skb);
 	}
 }