rxrpc: Improve the call tracking tracepoint

Improve the call tracking tracepoint by showing more differentiation
between some of the put and get events, including:

  (1) Getting and putting refs for the socket call user ID tree.

  (2) Getting and putting refs for queueing and failing to queue the call
      processor work item.

Note that these aren't necessarily used in this patch, but will be taken
advantage of in future patches.

An enum is added for the event subtype numbers rather than coding them
directly as decimal numbers and a table of 3-letter strings is provided
rather than a sequence of ?: operators.

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

1 files changed, 31 insertions, 17 deletions

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 65691742199b..3166b5222435 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -55,6 +55,21 @@ const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
 	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
 };
 
+const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = {
+	[rxrpc_call_new_client]		= "NWc",
+	[rxrpc_call_new_service]	= "NWs",
+	[rxrpc_call_queued]		= "QUE",
+	[rxrpc_call_queued_ref]		= "QUR",
+	[rxrpc_call_seen]		= "SEE",
+	[rxrpc_call_got]		= "GOT",
+	[rxrpc_call_got_skb]		= "Gsk",
+	[rxrpc_call_got_userid]		= "Gus",
+	[rxrpc_call_put]		= "PUT",
+	[rxrpc_call_put_skb]		= "Psk",
+	[rxrpc_call_put_userid]		= "Pus",
+	[rxrpc_call_put_noqueue]	= "PNQ",
+};
+
 struct kmem_cache *rxrpc_call_jar;
 LIST_HEAD(rxrpc_calls);
 DEFINE_RWLOCK(rxrpc_call_lock);
@@ -96,7 +111,7 @@ struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
 	return NULL;
 
 found_extant_call:
-	rxrpc_get_call(call);
+	rxrpc_get_call(call, rxrpc_call_got);
 	read_unlock(&rx->call_lock);
 	_leave(" = %p [%d]", call, atomic_read(&call->usage));
 	return call;
@@ -252,8 +267,7 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 			goto found_user_ID_now_present;
 	}
 
-	rxrpc_get_call(call);
-
+	rxrpc_get_call(call, rxrpc_call_got_userid);
 	rb_link_node(&call->sock_node, parent, pp);
 	rb_insert_color(&call->sock_node, &rx->calls);
 	write_unlock(&rx->call_lock);
@@ -275,7 +289,7 @@ error:
 	write_lock(&rx->call_lock);
 	rb_erase(&call->sock_node, &rx->calls);
 	write_unlock(&rx->call_lock);
-	rxrpc_put_call(call);
+	rxrpc_put_call(call, rxrpc_call_put_userid);
 
 	write_lock_bh(&rxrpc_call_lock);
 	list_del_init(&call->link);
@@ -283,7 +297,7 @@ error:
 
 	set_bit(RXRPC_CALL_RELEASED, &call->flags);
 	call->state = RXRPC_CALL_DEAD;
-	rxrpc_put_call(call);
+	rxrpc_put_call(call, rxrpc_call_put);
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
 
@@ -296,7 +310,7 @@ found_user_ID_now_present:
 	write_unlock(&rx->call_lock);
 	set_bit(RXRPC_CALL_RELEASED, &call->flags);
 	call->state = RXRPC_CALL_DEAD;
-	rxrpc_put_call(call);
+	rxrpc_put_call(call, rxrpc_call_put);
 	_leave(" = -EEXIST [%p]", call);
 	return ERR_PTR(-EEXIST);
 }
@@ -322,8 +336,8 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 	if (!candidate)
 		return ERR_PTR(-EBUSY);
 
-	trace_rxrpc_call(candidate, 1, atomic_read(&candidate->usage),
-			 0, here, NULL);
+	trace_rxrpc_call(candidate, rxrpc_call_new_service,
+			 atomic_read(&candidate->usage), 0, here, NULL);
 
 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 	candidate->socket	= rx;
@@ -358,7 +372,7 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 			read_unlock(&call->state_lock);
 			goto aborted_call;
 		default:
-			rxrpc_get_call(call);
+			rxrpc_get_call(call, rxrpc_call_got);
 			read_unlock(&call->state_lock);
 			goto extant_call;
 		}
@@ -447,20 +461,20 @@ void rxrpc_see_call(struct rxrpc_call *call)
 		int n = atomic_read(&call->usage);
 		int m = atomic_read(&call->skb_count);
 
-		trace_rxrpc_call(call, 2, n, m, here, 0);
+		trace_rxrpc_call(call, rxrpc_call_seen, n, m, here, NULL);
 	}
 }
 
 /*
  * Note the addition of a ref on a call.
  */
-void rxrpc_get_call(struct rxrpc_call *call)
+void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 {
 	const void *here = __builtin_return_address(0);
 	int n = atomic_inc_return(&call->usage);
 	int m = atomic_read(&call->skb_count);
 
-	trace_rxrpc_call(call, 3, n, m, here, 0);
+	trace_rxrpc_call(call, op, n, m, here, NULL);
 }
 
 /*
@@ -472,7 +486,7 @@ void rxrpc_get_call_for_skb(struct rxrpc_call *call, struct sk_buff *skb)
 	int n = atomic_inc_return(&call->usage);
 	int m = atomic_inc_return(&call->skb_count);
 
-	trace_rxrpc_call(call, 4, n, m, here, skb);
+	trace_rxrpc_call(call, rxrpc_call_got_skb, n, m, here, skb);
 }
 
 /*
@@ -575,7 +589,7 @@ static void rxrpc_dead_call_expired(unsigned long _call)
 	write_lock_bh(&call->state_lock);
 	call->state = RXRPC_CALL_DEAD;
 	write_unlock_bh(&call->state_lock);
-	rxrpc_put_call(call);
+	rxrpc_put_call(call, rxrpc_call_put);
 }
 
 /*
@@ -632,7 +646,7 @@ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 /*
  * release a call
  */
-void rxrpc_put_call(struct rxrpc_call *call)
+void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 {
 	const void *here = __builtin_return_address(0);
 	int n, m;
@@ -641,7 +655,7 @@ void rxrpc_put_call(struct rxrpc_call *call)
 
 	n = atomic_dec_return(&call->usage);
 	m = atomic_read(&call->skb_count);
-	trace_rxrpc_call(call, 5, n, m, here, NULL);
+	trace_rxrpc_call(call, op, n, m, here, NULL);
 	ASSERTCMP(n, >=, 0);
 	if (n == 0) {
 		_debug("call %d dead", call->debug_id);
@@ -661,7 +675,7 @@ void rxrpc_put_call_for_skb(struct rxrpc_call *call, struct sk_buff *skb)
 
 	n = atomic_dec_return(&call->usage);
 	m = atomic_dec_return(&call->skb_count);
-	trace_rxrpc_call(call, 6, n, m, here, skb);
+	trace_rxrpc_call(call, rxrpc_call_put_skb, n, m, here, skb);
 	ASSERTCMP(n, >=, 0);
 	if (n == 0) {
 		_debug("call %d dead", call->debug_id);