[PATCH net-next 2/3] net/smc: Introduce tracepoints for tx and rx msg

Tony Lu
2021-11-01T07:41:02Z

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>
---
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 170b733bc736..51e8eb2933ff 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 861a41644971..af031811ddb3 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 3bc97f5f2134..eced1546afae 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 738a4a99c827..be241d53020f 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;
--
2.19.1.6.gb485710b