rxrpc: Add a reason indicator to the tx_data tracepoint

Add an indicator to the rxrpc_tx_data tracepoint to indicate what triggered
the transmission of a particular packet.  At this point, it's only normal
transmission and retransmission, plus the tracepoint is also used to record
loss injection, but in a future patch, TLP-induced (re-)transmission will
also be a thing.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 326a4c257aeaec2f79a362f09e22f9f18f06f465..d79623fff74644e648267aebe6218d8059e55001 100644 (file)
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -302,6 +302,11 @@
        EM(rxrpc_txqueue_rotate_last,           "RLS") \
        E_(rxrpc_txqueue_wait,                  "WAI")
 
+#define rxrpc_txdata_traces \
+       EM(rxrpc_txdata_inject_loss,            " *INJ-LOSS*") \
+       EM(rxrpc_txdata_new_data,               " ") \
+       E_(rxrpc_txdata_retransmit,             " *RETRANS*")
+
 #define rxrpc_receive_traces \
        EM(rxrpc_receive_end,                   "END") \
        EM(rxrpc_receive_front,                 "FRN") \
@@ -534,6 +539,7 @@ enum rxrpc_timer_trace              { rxrpc_timer_traces } __mode(byte);
 enum rxrpc_tq_trace            { rxrpc_tq_traces } __mode(byte);
 enum rxrpc_tx_point            { rxrpc_tx_points } __mode(byte);
 enum rxrpc_txbuf_trace         { rxrpc_txbuf_traces } __mode(byte);
+enum rxrpc_txdata_trace                { rxrpc_txdata_traces } __mode(byte);
 enum rxrpc_txqueue_trace       { rxrpc_txqueue_traces } __mode(byte);
 
 #endif /* end __RXRPC_DECLARE_TRACE_ENUMS_ONCE_ONLY */
@@ -572,6 +578,7 @@ rxrpc_timer_traces;
 rxrpc_tq_traces;
 rxrpc_tx_points;
 rxrpc_txbuf_traces;
+rxrpc_txdata_traces;
 rxrpc_txqueue_traces;
 
 /*
@@ -1222,9 +1229,10 @@ TRACE_EVENT(rxrpc_tx_packet,
 
 TRACE_EVENT(rxrpc_tx_data,
            TP_PROTO(struct rxrpc_call *call, rxrpc_seq_t seq,
-                    rxrpc_serial_t serial, unsigned int flags, bool lose),
+                    rxrpc_serial_t serial, unsigned int flags,
+                    enum rxrpc_txdata_trace trace),
 
-           TP_ARGS(call, seq, serial, flags, lose),
+           TP_ARGS(call, seq, serial, flags, trace),
 
            TP_STRUCT__entry(
                    __field(unsigned int,       call)
@@ -1233,7 +1241,7 @@ TRACE_EVENT(rxrpc_tx_data,
                    __field(u32,                cid)
                    __field(u32,                call_id)
                    __field(u16,                flags)
-                   __field(bool,               lose)
+                   __field(enum rxrpc_txdata_trace, trace)
                             ),
 
            TP_fast_assign(
@@ -1243,18 +1251,17 @@ TRACE_EVENT(rxrpc_tx_data,
                    __entry->seq = seq;
                    __entry->serial = serial;
                    __entry->flags = flags;
-                   __entry->lose = lose;
+                   __entry->trace = trace;
                           ),
 
-           TP_printk("c=%08x DATA %08x:%08x %08x q=%08x fl=%02x%s%s",
+           TP_printk("c=%08x DATA %08x:%08x %08x q=%08x fl=%02x%s",
                      __entry->call,
                      __entry->cid,
                      __entry->call_id,
                      __entry->serial,
                      __entry->seq,
                      __entry->flags & RXRPC_TXBUF_WIRE_FLAGS,
-                     __entry->flags & RXRPC_TXBUF_RESENT ? " *RETRANS*" : "",
-                     __entry->lose ? " *LOSE*" : "")
+                     __print_symbolic(__entry->trace, rxrpc_txdata_traces))
            );
 
 TRACE_EVENT(rxrpc_tx_ack,

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index aa240b4b4bec3604f8db02be0be72ed35b8a8156..139575032ae2bab0fc8de3c609eda2394136b727 100644 (file)
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -883,6 +883,7 @@ struct rxrpc_send_data_req {
        rxrpc_seq_t             seq;            /* Sequence of first data */
        int                     n;              /* Number of DATA packets to glue into jumbo */
        bool                    did_send;       /* T if did actually send */
+       int /* enum rxrpc_txdata_trace */ trace;
 };
 
 #include <trace/events/rxrpc.h>

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 39772459426ba648ccd727eb367aaa2ad0570c3b..99d9502564cc9f26692097d5ec071115914d70ae 100644 (file)
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -101,6 +101,7 @@ void rxrpc_resend(struct rxrpc_call *call, rxrpc_serial_t ack_serial, bool ping_
 {
        struct rxrpc_send_data_req req = {
                .now    = ktime_get_real(),
+               .trace  = rxrpc_txdata_retransmit,
        };
        struct rxrpc_txqueue *tq = call->tx_queue;
        ktime_t lowest_xmit_ts = KTIME_MAX;
@@ -269,7 +270,8 @@ static unsigned int rxrpc_tx_window_space(struct rxrpc_call *call)
 /*
  * Transmit some as-yet untransmitted data.
  */
-static void rxrpc_transmit_fresh_data(struct rxrpc_call *call)
+static void rxrpc_transmit_fresh_data(struct rxrpc_call *call,
+                                     enum rxrpc_txdata_trace trace)
 {
        int space = rxrpc_tx_window_space(call);
 
@@ -284,6 +286,7 @@ static void rxrpc_transmit_fresh_data(struct rxrpc_call *call)
                        .now    = ktime_get_real(),
                        .seq    = call->tx_transmitted + 1,
                        .n      = 0,
+                       .trace  = trace,
                };
                struct rxrpc_txqueue *tq;
                struct rxrpc_txbuf *txb;
@@ -332,7 +335,8 @@ static void rxrpc_transmit_fresh_data(struct rxrpc_call *call)
        }
 }
 
-static void rxrpc_transmit_some_data(struct rxrpc_call *call)
+static void rxrpc_transmit_some_data(struct rxrpc_call *call,
+                                    enum rxrpc_txdata_trace trace)
 {
        switch (__rxrpc_call_state(call)) {
        case RXRPC_CALL_SERVER_ACK_REQUEST:
@@ -349,7 +353,7 @@ static void rxrpc_transmit_some_data(struct rxrpc_call *call)
                        rxrpc_inc_stat(call->rxnet, stat_tx_data_underflow);
                        return;
                }
-               rxrpc_transmit_fresh_data(call);
+               rxrpc_transmit_fresh_data(call, trace);
                break;
        default:
                return;
@@ -463,7 +467,7 @@ bool rxrpc_input_call_event(struct rxrpc_call *call)
                resend = true;
        }
 
-       rxrpc_transmit_some_data(call);
+       rxrpc_transmit_some_data(call, rxrpc_txdata_new_data);
 
        now = ktime_get_real();
        t = ktime_sub(call->keepalive_at, now);

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index a7de8a02f41998c55ebee5d4bd0cab0118469b37..2633f955d1d0e7c937cc666f01331033e27d087a 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -511,7 +511,7 @@ dont_set_request_ack:
                len += sizeof(*jumbo);
        }
 
-       trace_rxrpc_tx_data(call, txb->seq, txb->serial, txb->flags | flags, false);
+       trace_rxrpc_tx_data(call, txb->seq, txb->serial, flags, req->trace);
        kv->iov_len = len;
        return len;
 }
@@ -655,8 +655,8 @@ void rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_send_data_req
 
                if ((lose++ & 7) == 7) {
                        ret = 0;
-                       trace_rxrpc_tx_data(call, txb->seq, txb->serial,
-                                           txb->flags, true);
+                       trace_rxrpc_tx_data(call, txb->seq, txb->serial, txb->flags,
+                                           rxrpc_txdata_inject_loss);
                        conn->peer->last_tx_at = ktime_get_seconds();
                        goto done;
                }