rxrpc: Trace resend

Add a tracepoint to trace packet resend events and to dump the Tx
annotation buffer for added illumination.

Signed-off-by: David Howells <dhowells@rdhat.com>

2 files changed, 25 insertions, 0 deletions

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 36cb50c111a6..41979f907575 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -420,6 +420,7 @@ rxrpc_rtt_rx_traces;
 rxrpc_timer_traces;
 rxrpc_propose_ack_traces;
 rxrpc_propose_ack_outcomes;
+rxrpc_congest_modes;
 rxrpc_congest_changes;
 
 /*
@@ -1229,6 +1230,29 @@ TRACE_EVENT(rxrpc_connect_call,
                       __entry->call_id)
             );
 
+TRACE_EVENT(rxrpc_resend,
+            TP_PROTO(struct rxrpc_call *call, int ix),
+
+            TP_ARGS(call, ix),
+
+            TP_STRUCT__entry(
+                    __field(struct rxrpc_call *,        call            )
+                    __field(int,                        ix              )
+                    __array(u8,                         anno, 64        )
+                             ),
+
+            TP_fast_assign(
+                    __entry->call = call;
+                    __entry->ix = ix;
+                    memcpy(__entry->anno, call->rxtx_annotations, 64);
+                           ),
+
+            TP_printk("c=%p ix=%u a=%64phN",
+                      __entry->call,
+                      __entry->ix,
+                      __entry->anno)
+            );
+
 #endif /* _TRACE_RXRPC_H */
 
 /* This part must be outside protection */
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index ad2ab1103189..6a62e42e1d8d 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -195,6 +195,7 @@ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
          * the packets in the Tx buffer we're going to resend and what the new
          * resend timeout will be.
          */
+        trace_rxrpc_resend(call, (cursor + 1) & RXRPC_RXTX_BUFF_MASK);
         oldest = now;
         for (seq = cursor + 1; before_eq(seq, top); seq++) {
                 ix = seq & RXRPC_RXTX_BUFF_MASK;