[PATCH net-next 0/2] sunvnet: perf tracepoint hooks

[PATCH net-next 0/2] sunvnet: perf tracepoint hooks

[Sowmini Varadhan]

Added some perf tracepoints to help track and debug sunvnet 
descriptor state at run-time.

Sowmini Varadhan (2):
  sunvnet: Add support for perf LDC event tracing
  sunvnet: perf tracepoint invocations to trace LDC state machine

 drivers/net/ethernet/sun/sunvnet.c |   24 ++++++-
 include/trace/events/sunvnet.h     |  139 ++++++++++++++++++++++++++++++++++++
 2 files changed, 161 insertions(+), 2 deletions(-)
 create mode 100644 include/trace/events/sunvnet.h

[PATCH net-next 1/2] sunvnet: Add support for perf LDC event tracing

[Sowmini Varadhan]

Add perf event macros for support of tracing and instrumentation
of LDC state machine

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
---
 include/trace/events/sunvnet.h |  139 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 139 insertions(+), 0 deletions(-)
 create mode 100644 include/trace/events/sunvnet.h

diff --git a/include/trace/events/sunvnet.h b/include/trace/events/sunvnet.h
new file mode 100644
index 0000000..eb080b2
--- /dev/null
+++ b/include/trace/events/sunvnet.h
@@ -0,0 +1,139 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM sunvnet
+
+#if !defined(_TRACE_SUNVNET_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SUNVNET_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(vnet_rx_one,
+
+	TP_PROTO(int lsid, int rsid, int index, int needs_ack),
+
+	TP_ARGS(lsid, rsid, index, needs_ack),
+
+	TP_STRUCT__entry(
+		__field(int, lsid)
+		__field(int, rsid)
+		__field(int, index)
+		__field(int, needs_ack)
+	),
+
+	TP_fast_assign(
+		__entry->lsid = lsid;
+		__entry->rsid = rsid;
+		__entry->index = index;
+		__entry->needs_ack = needs_ack;
+	),
+
+	TP_printk("(%x:%x) walk_rx_one index %d; needs_ack %d",
+		__entry->lsid, __entry->rsid,
+		__entry->index, __entry->needs_ack)
+);
+
+DECLARE_EVENT_CLASS(vnet_tx_stopped_ack_template,
+
+	TP_PROTO(int lsid, int rsid, int ack_end, int npkts),
+
+	TP_ARGS(lsid, rsid, ack_end, npkts),
+
+	TP_STRUCT__entry(
+		__field(int, lsid)
+		__field(int, rsid)
+		__field(int, ack_end)
+		__field(int, npkts)
+	),
+
+	TP_fast_assign(
+		__entry->lsid = lsid;
+		__entry->rsid = rsid;
+		__entry->ack_end = ack_end;
+		__entry->npkts = npkts;
+	),
+
+	TP_printk("(%x:%x) stopped ack for %d; npkts %d",
+		__entry->lsid, __entry->rsid,
+		__entry->ack_end, __entry->npkts)
+);
+DEFINE_EVENT(vnet_tx_stopped_ack_template, vnet_tx_send_stopped_ack,
+	     TP_PROTO(int lsid, int rsid, int ack_end, int npkts),
+	     TP_ARGS(lsid, rsid, ack_end, npkts));
+DEFINE_EVENT(vnet_tx_stopped_ack_template, vnet_tx_defer_stopped_ack,
+	     TP_PROTO(int lsid, int rsid, int ack_end, int npkts),
+	     TP_ARGS(lsid, rsid, ack_end, npkts));
+DEFINE_EVENT(vnet_tx_stopped_ack_template, vnet_tx_pending_stopped_ack,
+	     TP_PROTO(int lsid, int rsid, int ack_end, int npkts),
+	     TP_ARGS(lsid, rsid, ack_end, npkts));
+
+TRACE_EVENT(vnet_rx_stopped_ack,
+
+	TP_PROTO(int lsid, int rsid, int end),
+
+	TP_ARGS(lsid, rsid, end),
+
+	TP_STRUCT__entry(
+		__field(int, lsid)
+		__field(int, rsid)
+		__field(int, end)
+	),
+
+	TP_fast_assign(
+		__entry->lsid = lsid;
+		__entry->rsid = rsid;
+		__entry->end = end;
+	),
+
+	TP_printk("(%x:%x) stopped ack for index %d",
+		__entry->lsid, __entry->rsid, __entry->end)
+);
+
+TRACE_EVENT(vnet_tx_trigger,
+
+	TP_PROTO(int lsid, int rsid, int start, int err),
+
+	TP_ARGS(lsid, rsid, start, err),
+
+	TP_STRUCT__entry(
+		__field(int, lsid)
+		__field(int, rsid)
+		__field(int, start)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->lsid = lsid;
+		__entry->rsid = rsid;
+		__entry->start = start;
+		__entry->err = err;
+	),
+
+	TP_printk("(%x:%x) Tx trigger for %d sent with err %d %s",
+		__entry->lsid, __entry->rsid, __entry->start,
+		__entry->err, __entry->err > 0 ? "(ok)" : " ")
+);
+
+TRACE_EVENT(vnet_skip_tx_trigger,
+
+	TP_PROTO(int lsid, int rsid, int last),
+
+	TP_ARGS(lsid, rsid, last),
+
+	TP_STRUCT__entry(
+		__field(int, lsid)
+		__field(int, rsid)
+		__field(int, last)
+	),
+
+	TP_fast_assign(
+		__entry->lsid = lsid;
+		__entry->rsid = rsid;
+		__entry->last = last;
+	),
+
+	TP_printk("(%x:%x) Skip Tx trigger. Last trigger sent was %d",
+		__entry->lsid, __entry->rsid, __entry->last)
+);
+#endif /* _TRACE_SOCK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
1.7.1

[PATCH net-next 2/2] sunvnet: perf tracepoint invocations to trace LDC state machine

[Sowmini Varadhan]

Use sunvnet perf trace macros to monitor LDC message exchange state.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
---
 drivers/net/ethernet/sun/sunvnet.c |   24 ++++++++++++++++++++++--
 1 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index 23fa298..942a95d 100644
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -17,6 +17,8 @@
 #include <linux/mutex.h>
 #include <linux/highmem.h>
 #include <linux/if_vlan.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/sunvnet.h>
 
 #if IS_ENABLED(CONFIG_IPV6)
 #include <linux/icmpv6.h>
@@ -540,6 +542,8 @@ static int vnet_walk_rx_one(struct vnet_port *port,
 	err = vnet_rx_one(port, desc);
 	if (err == -ECONNRESET)
 		return err;
+	trace_vnet_rx_one(port->vio._local_sid, port->vio._peer_sid,
+			  index, desc->hdr.ack);
 	desc->hdr.state = VIO_DESC_DONE;
 	err = put_rx_desc(port, dr, desc, index);
 	if (err < 0)
@@ -587,9 +591,15 @@ static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
 		ack_start = ack_end = vio_dring_prev(dr, start);
 	if (send_ack) {
 		port->napi_resume = false;
+		trace_vnet_tx_send_stopped_ack(port->vio._local_sid,
+					       port->vio._peer_sid,
+					       ack_end, *npkts);
 		return vnet_send_ack(port, dr, ack_start, ack_end,
 				     VIO_DRING_STOPPED);
 	} else  {
+		trace_vnet_tx_defer_stopped_ack(port->vio._local_sid,
+						port->vio._peer_sid,
+						ack_end, *npkts);
 		port->napi_resume = true;
 		port->napi_stop_idx = ack_end;
 		return 1;
@@ -663,6 +673,8 @@ static int vnet_ack(struct vnet_port *port, void *msgbuf)
 	/* sync for race conditions with vnet_start_xmit() and tell xmit it
 	 * is time to send a trigger.
 	 */
+	trace_vnet_rx_stopped_ack(port->vio._local_sid,
+				  port->vio._peer_sid, end);
 	dr->cons = vio_dring_next(dr, end);
 	desc = vio_dring_entry(dr, dr->cons);
 	if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
@@ -886,6 +898,9 @@ static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
 	int retries = 0;
 
 	if (port->stop_rx) {
+		trace_vnet_tx_pending_stopped_ack(port->vio._local_sid,
+						  port->vio._peer_sid,
+						  port->stop_rx_idx, -1);
 		err = vnet_send_ack(port,
 				    &port->vio.drings[VIO_DRIVER_RX_RING],
 				    port->stop_rx_idx, -1,
@@ -908,6 +923,8 @@ static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
 		if (retries++ > VNET_MAX_RETRIES)
 			break;
 	} while (err == -EAGAIN);
+	trace_vnet_tx_trigger(port->vio._local_sid,
+			      port->vio._peer_sid, start, err);
 
 	return err;
 }
@@ -1414,8 +1431,11 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	 * producer to consumer announcement that work is available to the
 	 * consumer
 	 */
-	if (!port->start_cons)
-		goto ldc_start_done; /* previous trigger suffices */
+	if (!port->start_cons) { /* previous trigger suffices */
+		trace_vnet_skip_tx_trigger(port->vio._local_sid,
+					   port->vio._peer_sid, dr->cons);
+		goto ldc_start_done;
+	}
 
 	err = __vnet_tx_trigger(port, dr->cons);
 	if (unlikely(err < 0)) {
-- 
1.7.1

Re: [PATCH net-next 0/2] sunvnet: perf tracepoint hooks

[David Miller]

From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Date: Tue,  2 Feb 2016 10:41:54 -0800

> Added some perf tracepoints to help track and debug sunvnet 
> descriptor state at run-time.

I'm not the biggest fan of putting tracepoints like this in the fast
paths of a networking driver, but what can I say... if they are useful
for you I guess I'm ok with it.

Series applied, thanks.