rxrpc: Differentiate PING ACK transmission traces.

There are three points that transmit PING ACKs and all of them use the same
trace string.  Change two of them to use different strings.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

include/trace/events/rxrpc.h

@@ -364,11 +364,13 @@
 
 #define rxrpc_propose_ack_traces \
 	EM(rxrpc_propose_ack_client_tx_end,	"ClTxEnd") \
+	EM(rxrpc_propose_ack_delayed_ack,	"DlydAck") \
 	EM(rxrpc_propose_ack_input_data,	"DataIn ") \
 	EM(rxrpc_propose_ack_input_data_hole,	"DataInH") \
 	EM(rxrpc_propose_ack_ping_for_keepalive, "KeepAlv") \
 	EM(rxrpc_propose_ack_ping_for_lost_ack,	"LostAck") \
 	EM(rxrpc_propose_ack_ping_for_lost_reply, "LostRpl") \
+	EM(rxrpc_propose_ack_ping_for_0_retrans, "0-Retrn") \
 	EM(rxrpc_propose_ack_ping_for_old_rtt,	"OldRtt ") \
 	EM(rxrpc_propose_ack_ping_for_params,	"Params ") \
 	EM(rxrpc_propose_ack_ping_for_rtt,	"Rtt    ") \

net/rxrpc/call_event.c

@@ -197,7 +197,7 @@ void rxrpc_resend(struct rxrpc_call *call, struct sk_buff *ack_skb)
 		if (ktime_to_us(ack_ts) < (call->peer->srtt_us >> 3))
 			goto out;
 		rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
-			       rxrpc_propose_ack_ping_for_lost_ack);
+			       rxrpc_propose_ack_ping_for_0_retrans);
 		goto out;
 	}
 
@@ -387,7 +387,7 @@ bool rxrpc_input_call_event(struct rxrpc_call *call, struct sk_buff *skb)
 		trace_rxrpc_timer(call, rxrpc_timer_exp_ack, now);
 		call->delay_ack_at = now + MAX_JIFFY_OFFSET;
 		rxrpc_send_ACK(call, RXRPC_ACK_DELAY, 0,
-			       rxrpc_propose_ack_ping_for_lost_ack);
+			       rxrpc_propose_ack_delayed_ack);
 	}
 
 	t = call->ack_lost_at;