From a124fe3ee5d82f2c9a9b8818ed5cb9f61685f1d3 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Sat, 17 Sep 2016 10:49:13 +0100
Subject: rxrpc: Add a tracepoint to follow the life of a packet in the Tx
 buffer

Add a tracepoint to follow the insertion of a packet into the transmit
buffer, its transmission and its rotation out of the buffer.

Signed-off-by: David Howells <dhowells@redhat.com>
---
 net/rxrpc/ar-internal.h | 12 ++++++++++++
 net/rxrpc/input.c       |  2 ++
 net/rxrpc/misc.c        |  9 +++++++++
 net/rxrpc/sendmsg.c     |  9 ++++++++-
 4 files changed, 31 insertions(+), 1 deletion(-)

(limited to 'net')

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 6ca40eea3022..afa5dcc05fe0 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -593,6 +593,18 @@ enum rxrpc_call_trace {
 
 extern const char rxrpc_call_traces[rxrpc_call__nr_trace][4];
 
+enum rxrpc_transmit_trace {
+	rxrpc_transmit_wait,
+	rxrpc_transmit_queue,
+	rxrpc_transmit_queue_reqack,
+	rxrpc_transmit_queue_last,
+	rxrpc_transmit_rotate,
+	rxrpc_transmit_end,
+	rxrpc_transmit__nr_trace
+};
+
+extern const char rxrpc_transmit_traces[rxrpc_transmit__nr_trace][4];
+
 extern const char *const rxrpc_pkts[];
 extern const char *rxrpc_acks(u8 reason);
 
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index c1f83d22f9b7..c7eb5104e91a 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -59,6 +59,7 @@ static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to)
 
 	spin_unlock(&call->lock);
 
+	trace_rxrpc_transmit(call, rxrpc_transmit_rotate);
 	wake_up(&call->waitq);
 
 	while (list) {
@@ -107,6 +108,7 @@ static bool rxrpc_end_tx_phase(struct rxrpc_call *call, const char *abort_why)
 	}
 
 	write_unlock(&call->state_lock);
+	trace_rxrpc_transmit(call, rxrpc_transmit_end);
 	_leave(" = ok");
 	return true;
 }
diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
index 598064d3bdd2..dca89995f03e 100644
--- a/net/rxrpc/misc.c
+++ b/net/rxrpc/misc.c
@@ -132,3 +132,12 @@ const char rxrpc_client_traces[rxrpc_client__nr_trace][7] = {
 	[rxrpc_client_to_waiting]	= "->Wait",
 	[rxrpc_client_uncount]		= "Uncoun",
 };
+
+const char rxrpc_transmit_traces[rxrpc_transmit__nr_trace][4] = {
+	[rxrpc_transmit_wait]		= "WAI",
+	[rxrpc_transmit_queue]		= "QUE",
+	[rxrpc_transmit_queue_reqack]	= "QRA",
+	[rxrpc_transmit_queue_last]	= "QLS",
+	[rxrpc_transmit_rotate]		= "ROT",
+	[rxrpc_transmit_end]		= "END",
+};
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 8bfddf4e338c..28d8f73cf11d 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -56,6 +56,7 @@ static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 			break;
 		}
 
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
 		release_sock(&rx->sk);
 		*timeo = schedule_timeout(*timeo);
 		lock_sock(&rx->sk);
@@ -104,8 +105,14 @@ static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
 	smp_wmb();
 	call->rxtx_buffer[ix] = skb;
 	call->tx_top = seq;
-	if (last)
+	if (last) {
 		set_bit(RXRPC_CALL_TX_LAST, &call->flags);
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
+	} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue_reqack);
+	} else {
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
+	}
 
 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 		_debug("________awaiting reply/ACK__________");
-- 
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