rxrpc: Use the tx-phase skb flag to simplify tracing

Use the previously-added transmit-phase skbuff private flag to simplify the
socket buffer tracing a bit.  Which phase the skbuff comes from can now be
divined from the skb rather than having to be guessed from the call state.

We can also reduce the number of rxrpc_skb_trace values by eliminating the
difference between Tx and Rx in the symbols.
Signed-off-by: David Howells <dhowells@redhat.com>

include/trace/events/rxrpc.h

@@ -23,20 +23,15 @@
 #define __RXRPC_DECLARE_TRACE_ENUMS_ONCE_ONLY
 
 enum rxrpc_skb_trace {
-	rxrpc_skb_rx_cleaned,
-	rxrpc_skb_rx_freed,
-	rxrpc_skb_rx_got,
-	rxrpc_skb_rx_lost,
-	rxrpc_skb_rx_purged,
-	rxrpc_skb_rx_received,
-	rxrpc_skb_rx_rotated,
-	rxrpc_skb_rx_seen,
-	rxrpc_skb_tx_cleaned,
-	rxrpc_skb_tx_freed,
-	rxrpc_skb_tx_got,
-	rxrpc_skb_tx_new,
-	rxrpc_skb_tx_rotated,
-	rxrpc_skb_tx_seen,
+	rxrpc_skb_cleaned,
+	rxrpc_skb_freed,
+	rxrpc_skb_got,
+	rxrpc_skb_lost,
+	rxrpc_skb_new,
+	rxrpc_skb_purged,
+	rxrpc_skb_received,
+	rxrpc_skb_rotated,
+	rxrpc_skb_seen,
 };
 
 enum rxrpc_local_trace {
@@ -228,20 +223,15 @@ enum rxrpc_tx_point {
  * Declare tracing information enums and their string mappings for display.
  */
 #define rxrpc_skb_traces \
-	EM(rxrpc_skb_rx_cleaned,		"Rx CLN") \
-	EM(rxrpc_skb_rx_freed,			"Rx FRE") \
-	EM(rxrpc_skb_rx_got,			"Rx GOT") \
-	EM(rxrpc_skb_rx_lost,			"Rx *L*") \
-	EM(rxrpc_skb_rx_purged,			"Rx PUR") \
-	EM(rxrpc_skb_rx_received,		"Rx RCV") \
-	EM(rxrpc_skb_rx_rotated,		"Rx ROT") \
-	EM(rxrpc_skb_rx_seen,			"Rx SEE") \
-	EM(rxrpc_skb_tx_cleaned,		"Tx CLN") \
-	EM(rxrpc_skb_tx_freed,			"Tx FRE") \
-	EM(rxrpc_skb_tx_got,			"Tx GOT") \
-	EM(rxrpc_skb_tx_new,			"Tx NEW") \
-	EM(rxrpc_skb_tx_rotated,		"Tx ROT") \
-	E_(rxrpc_skb_tx_seen,			"Tx SEE")
+	EM(rxrpc_skb_cleaned,			"CLN") \
+	EM(rxrpc_skb_freed,			"FRE") \
+	EM(rxrpc_skb_got,			"GOT") \
+	EM(rxrpc_skb_lost,			"*L*") \
+	EM(rxrpc_skb_new,			"NEW") \
+	EM(rxrpc_skb_purged,			"PUR") \
+	EM(rxrpc_skb_received,			"RCV") \
+	EM(rxrpc_skb_rotated,			"ROT") \
+	E_(rxrpc_skb_seen,			"SEE")
 
 #define rxrpc_local_traces \
 	EM(rxrpc_local_got,			"GOT") \
@@ -650,6 +640,7 @@ TRACE_EVENT(rxrpc_skb,
 	    TP_STRUCT__entry(
 		    __field(struct sk_buff *,		skb		)
 		    __field(enum rxrpc_skb_trace,	op		)
+		    __field(u8,				flags		)
 		    __field(int,			usage		)
 		    __field(int,			mod_count	)
 		    __field(const void *,		where		)
@@ -657,14 +648,16 @@ TRACE_EVENT(rxrpc_skb,
 
 	    TP_fast_assign(
 		    __entry->skb = skb;
+		    __entry->flags = rxrpc_skb(skb)->rx_flags;
 		    __entry->op = op;
 		    __entry->usage = usage;
 		    __entry->mod_count = mod_count;
 		    __entry->where = where;
 			   ),
 
-	    TP_printk("s=%p %s u=%d m=%d p=%pSR",
+	    TP_printk("s=%p %cx %s u=%d m=%d p=%pSR",
 		      __entry->skb,
+		      __entry->flags & RXRPC_SKB_TX_BUFFER ? 'T' : 'R',
 		      __print_symbolic(__entry->op, rxrpc_skb_traces),
 		      __entry->usage,
 		      __entry->mod_count,

net/rxrpc/ar-internal.h

@@ -185,6 +185,7 @@ struct rxrpc_host_header {
  * - max 48 bytes (struct sk_buff::cb)
  */
 struct rxrpc_skb_priv {
+	atomic_t	nr_ring_pins;		/* Number of rxtx ring pins */
 	u8		nr_subpackets;		/* Number of subpackets */
 	u8		rx_flags;		/* Received packet flags */
 #define RXRPC_SKB_INCL_LAST	0x01		/* - Includes last packet */

net/rxrpc/call_event.c

@@ -199,7 +199,7 @@ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
 			continue;
 
 		skb = call->rxtx_buffer[ix];
-		rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
 
 		if (anno_type == RXRPC_TX_ANNO_UNACK) {
 			if (ktime_after(skb->tstamp, max_age)) {
@@ -255,18 +255,18 @@ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
 			continue;
 
 		skb = call->rxtx_buffer[ix];
-		rxrpc_get_skb(skb, rxrpc_skb_tx_got);
+		rxrpc_get_skb(skb, rxrpc_skb_got);
 		spin_unlock_bh(&call->lock);
 
 		if (rxrpc_send_data_packet(call, skb, true) < 0) {
-			rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
 			return;
 		}
 
 		if (rxrpc_is_client_call(call))
 			rxrpc_expose_client_call(call);
 
-		rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 		spin_lock_bh(&call->lock);
 
 		/* We need to clear the retransmit state, but there are two

net/rxrpc/call_object.c

@@ -429,9 +429,7 @@ static void rxrpc_cleanup_ring(struct rxrpc_call *call)
 	int i;
 
 	for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
-		rxrpc_free_skb(call->rxtx_buffer[i],
-			       (call->tx_phase ? rxrpc_skb_tx_cleaned :
-				rxrpc_skb_rx_cleaned));
+		rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned);
 		call->rxtx_buffer[i] = NULL;
 	}
 }
@@ -587,7 +585,7 @@ void rxrpc_cleanup_call(struct rxrpc_call *call)
 	ASSERTCMP(call->conn, ==, NULL);
 
 	rxrpc_cleanup_ring(call);
-	rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
+	rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned);
 
 	call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 }

net/rxrpc/conn_event.c

@@ -472,7 +472,7 @@ void rxrpc_process_connection(struct work_struct *work)
 	/* go through the conn-level event packets, releasing the ref on this
 	 * connection that each one has when we've finished with it */
 	while ((skb = skb_dequeue(&conn->rx_queue))) {
-		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
 		ret = rxrpc_process_event(conn, skb, &abort_code);
 		switch (ret) {
 		case -EPROTO:
@@ -484,7 +484,7 @@ void rxrpc_process_connection(struct work_struct *work)
 			goto requeue_and_leave;
 		case -ECONNABORTED:
 		default:
-			rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
 			break;
 		}
 	}
@@ -501,6 +501,6 @@ void rxrpc_process_connection(struct work_struct *work)
 protocol_error:
 	if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 		goto requeue_and_leave;
-	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 	goto out;
 }

net/rxrpc/input.c

@@ -233,7 +233,7 @@ static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
 		ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
 		skb = call->rxtx_buffer[ix];
 		annotation = call->rxtx_annotations[ix];
-		rxrpc_see_skb(skb, rxrpc_skb_tx_rotated);
+		rxrpc_see_skb(skb, rxrpc_skb_rotated);
 		call->rxtx_buffer[ix] = NULL;
 		call->rxtx_annotations[ix] = 0;
 		skb->next = list;
@@ -258,7 +258,7 @@ static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
 		skb = list;
 		list = skb->next;
 		skb_mark_not_on_list(skb);
-		rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 	}
 
 	return rot_last;
@@ -443,7 +443,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 
 	state = READ_ONCE(call->state);
 	if (state >= RXRPC_CALL_COMPLETE) {
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 		return;
 	}
 
@@ -559,7 +559,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 		 * and also rxrpc_fill_out_ack().
 		 */
 		if (!terminal)
-			rxrpc_get_skb(skb, rxrpc_skb_rx_got);
+			rxrpc_get_skb(skb, rxrpc_skb_got);
 		call->rxtx_annotations[ix] = annotation;
 		smp_wmb();
 		call->rxtx_buffer[ix] = skb;
@@ -620,7 +620,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
 
 unlock:
 	spin_unlock(&call->input_lock);
-	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 	_leave(" [queued]");
 }
 
@@ -1056,7 +1056,7 @@ static void rxrpc_input_call_packet(struct rxrpc_call *call,
 		break;
 	}
 
-	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 no_free:
 	_leave("");
 }
@@ -1119,7 +1119,7 @@ static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
 		skb_queue_tail(&local->event_queue, skb);
 		rxrpc_queue_local(local);
 	} else {
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 	}
 }
 
@@ -1134,7 +1134,7 @@ static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 		skb_queue_tail(&local->reject_queue, skb);
 		rxrpc_queue_local(local);
 	} else {
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 	}
 }
 
@@ -1198,7 +1198,7 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 	if (skb->tstamp == 0)
 		skb->tstamp = ktime_get_real();
 
-	rxrpc_new_skb(skb, rxrpc_skb_rx_received);
+	rxrpc_new_skb(skb, rxrpc_skb_received);
 
 	skb_pull(skb, sizeof(struct udphdr));
 
@@ -1215,7 +1215,7 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 		static int lose;
 		if ((lose++ & 7) == 7) {
 			trace_rxrpc_rx_lose(sp);
-			rxrpc_free_skb(skb, rxrpc_skb_rx_lost);
+			rxrpc_free_skb(skb, rxrpc_skb_lost);
 			return 0;
 		}
 	}
@@ -1389,7 +1389,7 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
 	goto out;
 
 discard:
-	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 out:
 	trace_rxrpc_rx_done(0, 0);
 	return 0;

net/rxrpc/local_event.c

@@ -90,7 +90,7 @@ void rxrpc_process_local_events(struct rxrpc_local *local)
 	if (skb) {
 		struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 
-		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
 		_debug("{%d},{%u}", local->debug_id, sp->hdr.type);
 
 		switch (sp->hdr.type) {
@@ -108,7 +108,7 @@ void rxrpc_process_local_events(struct rxrpc_local *local)
 			break;
 		}
 
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 	}
 
 	_leave("");

net/rxrpc/output.c

@@ -565,7 +565,7 @@ void rxrpc_reject_packets(struct rxrpc_local *local)
 	memset(&whdr, 0, sizeof(whdr));
 
 	while ((skb = skb_dequeue(&local->reject_queue))) {
-		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
 		sp = rxrpc_skb(skb);
 
 		switch (skb->mark) {
@@ -581,7 +581,7 @@ void rxrpc_reject_packets(struct rxrpc_local *local)
 			ioc = 2;
 			break;
 		default:
-			rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
 			continue;
 		}
 
@@ -606,7 +606,7 @@ void rxrpc_reject_packets(struct rxrpc_local *local)
 						      rxrpc_tx_point_reject);
 		}
 
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 	}
 
 	_leave("");

net/rxrpc/peer_event.c

@@ -163,11 +163,11 @@ void rxrpc_error_report(struct sock *sk)
 		_leave("UDP socket errqueue empty");
 		return;
 	}
-	rxrpc_new_skb(skb, rxrpc_skb_rx_received);
+	rxrpc_new_skb(skb, rxrpc_skb_received);
 	serr = SKB_EXT_ERR(skb);
 	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
 		_leave("UDP empty message");
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 		return;
 	}
 
@@ -177,7 +177,7 @@ void rxrpc_error_report(struct sock *sk)
 		peer = NULL;
 	if (!peer) {
 		rcu_read_unlock();
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 		_leave(" [no peer]");
 		return;
 	}
@@ -189,7 +189,7 @@ void rxrpc_error_report(struct sock *sk)
 	     serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
 		rxrpc_adjust_mtu(peer, serr);
 		rcu_read_unlock();
-		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
 		rxrpc_put_peer(peer);
 		_leave(" [MTU update]");
 		return;
@@ -197,7 +197,7 @@ void rxrpc_error_report(struct sock *sk)
 
 	rxrpc_store_error(peer, serr);
 	rcu_read_unlock();
-	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 	rxrpc_put_peer(peer);
 
 	_leave("");

net/rxrpc/recvmsg.c

@@ -190,7 +190,7 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 	hard_ack++;
 	ix = hard_ack & RXRPC_RXTX_BUFF_MASK;
 	skb = call->rxtx_buffer[ix];
-	rxrpc_see_skb(skb, rxrpc_skb_rx_rotated);
+	rxrpc_see_skb(skb, rxrpc_skb_rotated);
 	sp = rxrpc_skb(skb);
 
 	subpacket = call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
@@ -205,7 +205,7 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 	/* Barrier against rxrpc_input_data(). */
 	smp_store_release(&call->rx_hard_ack, hard_ack);
 
-	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 
 	trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack);
 	if (last) {
@@ -340,7 +340,7 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 			break;
 		}
 		smp_rmb();
-		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
 		sp = rxrpc_skb(skb);
 
 		if (!(flags & MSG_PEEK)) {

net/rxrpc/sendmsg.c

@@ -176,7 +176,7 @@ static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 	skb->tstamp = ktime_get_real();
 
 	ix = seq & RXRPC_RXTX_BUFF_MASK;
-	rxrpc_get_skb(skb, rxrpc_skb_tx_got);
+	rxrpc_get_skb(skb, rxrpc_skb_got);
 	call->rxtx_annotations[ix] = annotation;
 	smp_wmb();
 	call->rxtx_buffer[ix] = skb;
@@ -248,7 +248,7 @@ static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 	}
 
 out:
-	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 	_leave(" = %d", ret);
 	return ret;
 }
@@ -289,7 +289,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
 
 	skb = call->tx_pending;
 	call->tx_pending = NULL;
-	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
+	rxrpc_see_skb(skb, rxrpc_skb_seen);
 
 	copied = 0;
 	do {
@@ -338,7 +338,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
 
 			sp = rxrpc_skb(skb);
 			sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
-			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
+			rxrpc_new_skb(skb, rxrpc_skb_new);
 
 			_debug("ALLOC SEND %p", skb);
 
@@ -440,7 +440,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
 	return ret;
 
 call_terminated:
-	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
 	_leave(" = %d", call->error);
 	return call->error;
 

net/rxrpc/skbuff.c

@@ -14,7 +14,8 @@
 #include <net/af_rxrpc.h>
 #include "ar-internal.h"
 
-#define select_skb_count(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
+#define is_tx_skb(skb) (rxrpc_skb(skb)->rx_flags & RXRPC_SKB_TX_BUFFER)
+#define select_skb_count(skb) (is_tx_skb(skb) ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
 
 /*
  * Note the allocation or reception of a socket buffer.
@@ -22,7 +23,7 @@
 void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_inc_return(select_skb_count(op));
+	int n = atomic_inc_return(select_skb_count(skb));
 	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
 }
 
@@ -33,7 +34,7 @@ void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
 {
 	const void *here = __builtin_return_address(0);
 	if (skb) {
-		int n = atomic_read(select_skb_count(op));
+		int n = atomic_read(select_skb_count(skb));
 		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
 	}
 }
@@ -44,7 +45,7 @@ void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
 void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_inc_return(select_skb_count(op));
+	int n = atomic_inc_return(select_skb_count(skb));
 	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
 	skb_get(skb);
 }
@@ -58,7 +59,7 @@ void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
 	if (skb) {
 		int n;
 		CHECK_SLAB_OKAY(&skb->users);
-		n = atomic_dec_return(select_skb_count(op));
+		n = atomic_dec_return(select_skb_count(skb));
 		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
 		kfree_skb(skb);
 	}
@@ -72,8 +73,8 @@ void rxrpc_purge_queue(struct sk_buff_head *list)
 	const void *here = __builtin_return_address(0);
 	struct sk_buff *skb;
 	while ((skb = skb_dequeue((list))) != NULL) {
-		int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged));
-		trace_rxrpc_skb(skb, rxrpc_skb_rx_purged,
+		int n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, rxrpc_skb_purged,
 				refcount_read(&skb->users), n, here);
 		kfree_skb(skb);
 	}