From aff3083f10bff7a37eaa2b4e6bc5fb627ddd5f84 Mon Sep 17 00:00:00 2001
From: Tony Lu <tonylu@linux.alibaba.com>
Date: Mon, 1 Nov 2021 15:39:14 +0800
Subject: [PATCH] net/smc: Introduce tracepoints for tx and rx msg

This introduce two tracepoints for smc tx and rx msg to help us
diagnosis issues of data path. These two tracepoitns don't cover the
path of CORK or MSG_MORE in tx, just the top half of data path.

Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/smc/smc_rx.c         |  3 +++
 net/smc/smc_tracepoint.c |  2 ++
 net/smc/smc_tracepoint.h | 37 +++++++++++++++++++++++++++++++++++++
 net/smc/smc_tx.c         |  3 +++
 4 files changed, 45 insertions(+)

diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index 170b733bc7367..51e8eb2933ff4 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -22,6 +22,7 @@
 #include "smc_tx.h" /* smc_tx_consumer_update() */
 #include "smc_rx.h"
 #include "smc_stats.h"
+#include "smc_tracepoint.h"
 
 /* callback implementation to wakeup consumers blocked with smc_rx_wait().
  * indirectly called by smc_cdc_msg_recv_action().
@@ -438,6 +439,8 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg,
 			if (msg && smc_rx_update_consumer(smc, cons, copylen))
 				goto out;
 		}
+
+		trace_smc_rx_recvmsg(smc, copylen);
 	} while (read_remaining);
 out:
 	return read_done;
diff --git a/net/smc/smc_tracepoint.c b/net/smc/smc_tracepoint.c
index 861a416449715..af031811ddb39 100644
--- a/net/smc/smc_tracepoint.c
+++ b/net/smc/smc_tracepoint.c
@@ -4,3 +4,5 @@
 #include "smc_tracepoint.h"
 
 EXPORT_TRACEPOINT_SYMBOL(smc_switch_to_fallback);
+EXPORT_TRACEPOINT_SYMBOL(smc_tx_sendmsg);
+EXPORT_TRACEPOINT_SYMBOL(smc_rx_recvmsg);
diff --git a/net/smc/smc_tracepoint.h b/net/smc/smc_tracepoint.h
index 3bc97f5f21340..eced1546afaeb 100644
--- a/net/smc/smc_tracepoint.h
+++ b/net/smc/smc_tracepoint.h
@@ -38,6 +38,43 @@ TRACE_EVENT(smc_switch_to_fallback,
 		      __entry->sk, __entry->clcsk, __entry->fallback_rsn)
 );
 
+DECLARE_EVENT_CLASS(smc_msg_event,
+
+		    TP_PROTO(const struct smc_sock *smc, size_t len),
+
+		    TP_ARGS(smc, len),
+
+		    TP_STRUCT__entry(
+				     __field(const void *, smc)
+				     __field(size_t, len)
+				     __string(name, smc->conn.lnk->ibname)
+		    ),
+
+		    TP_fast_assign(
+				   __entry->smc = smc;
+				   __entry->len = len;
+				   __assign_str(name, smc->conn.lnk->ibname);
+		    ),
+
+		    TP_printk("smc=%p len=%zu dev=%s",
+			      __entry->smc, __entry->len,
+			      __get_str(name))
+);
+
+DEFINE_EVENT(smc_msg_event, smc_tx_sendmsg,
+
+	     TP_PROTO(const struct smc_sock *smc, size_t len),
+
+	     TP_ARGS(smc, len)
+);
+
+DEFINE_EVENT(smc_msg_event, smc_rx_recvmsg,
+
+	     TP_PROTO(const struct smc_sock *smc, size_t len),
+
+	     TP_ARGS(smc, len)
+);
+
 #endif /* _TRACE_SMC_H */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index 738a4a99c8279..be241d53020f1 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -28,6 +28,7 @@
 #include "smc_ism.h"
 #include "smc_tx.h"
 #include "smc_stats.h"
+#include "smc_tracepoint.h"
 
 #define SMC_TX_WORK_DELAY	0
 #define SMC_TX_CORK_DELAY	(HZ >> 2)	/* 250 ms */
@@ -245,6 +246,8 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len)
 					   SMC_TX_CORK_DELAY);
 		else
 			smc_tx_sndbuf_nonempty(conn);
+
+		trace_smc_tx_sendmsg(smc, copylen);
 	} /* while (msg_data_left(msg)) */
 
 	return send_done;