To simplify debugging which process touches a watchdog and when, add
tracing events for .start(), .set_timeout(), .ping() and .stop().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
Changes since v2 sent with Message-Id:
20221004091950.3419662-1-u.kleine-koenig@xxxxxxxxxxxxxx:
- Reorder events in the header to have all DEFINE_EVENTS near their
DECLARE_EVENT_CLASS.
Changes since (implict) v1 sent with Message-Id:
20220930144935.3373366-1-u.kleine-koenig@xxxxxxxxxxxxxx:
- Make use of DECLARE_EVENT_CLASS as {requ,sugg}ested by Steven.
MAINTAINERS | 1 +
drivers/watchdog/watchdog_core.c | 4 ++
drivers/watchdog/watchdog_dev.c | 12 +++++-
include/trace/events/watchdog.h | 66 ++++++++++++++++++++++++++++++++
4 files changed, 81 insertions(+), 2 deletions(-)
create mode 100644 include/trace/events/watchdog.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 72b9654f764c..507de599116b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21890,6 +21890,7 @@ F: Documentation/watchdog/
F: drivers/watchdog/
F: include/linux/watchdog.h
F: include/uapi/linux/watchdog.h
+F: include/trace/events/watchdog.h
WHISKEYCOVE PMIC GPIO DRIVER
M: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 3fe8a7edc252..c777a612d932 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -38,6 +38,9 @@
#include "watchdog_core.h" /* For watchdog_dev_register/... */
+#define CREATE_TRACE_POINTS
+#include <trace/events/watchdog.h>
+
static DEFINE_IDA(watchdog_ida);
static int stop_on_reboot = -1;
@@ -163,6 +166,7 @@ static int watchdog_reboot_notifier(struct notifier_block *nb,
int ret;
ret = wdd->ops->stop(wdd);
+ trace_watchdog_stop(wdd, ret);
if (ret)
return NOTIFY_BAD;
}
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 54903f3c851e..3323309c913c 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -47,6 +47,8 @@
#include "watchdog_core.h"
#include "watchdog_pretimeout.h"
+#include <trace/events/watchdog.h>
+
/* the dev_t structure to store the dynamically allocated watchdog devices */
static dev_t watchdog_devt;
/* Reference to watchdog device behind /dev/watchdog */
@@ -157,10 +159,13 @@ static int __watchdog_ping(struct watchdog_device *wdd)
wd_data->last_hw_keepalive = now;
- if (wdd->ops->ping)
+ if (wdd->ops->ping) {
err = wdd->ops->ping(wdd); /* ping the watchdog */
- else
+ trace_watchdog_ping(wdd, err);
+ } else {
err = wdd->ops->start(wdd); /* restart watchdog */
+ trace_watchdog_start(wdd, err);
+ }
if (err == 0)
watchdog_hrtimer_pretimeout_start(wdd);
@@ -259,6 +264,7 @@ static int watchdog_start(struct watchdog_device *wdd)
}
} else {
err = wdd->ops->start(wdd);
+ trace_watchdog_start(wdd, err);
if (err == 0) {
set_bit(WDOG_ACTIVE, &wdd->status);
wd_data->last_keepalive = started_at;
@@ -297,6 +303,7 @@ static int watchdog_stop(struct watchdog_device *wdd)
if (wdd->ops->stop) {
clear_bit(WDOG_HW_RUNNING, &wdd->status);
err = wdd->ops->stop(wdd);
+ trace_watchdog_stop(wdd, err);
} else {
set_bit(WDOG_HW_RUNNING, &wdd->status);
}
@@ -369,6 +376,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
if (wdd->ops->set_timeout) {
err = wdd->ops->set_timeout(wdd, timeout);
+ trace_watchdog_set_timeout(wdd, timeout, err);
} else {
wdd->timeout = timeout;
/* Disable pretimeout if it doesn't fit the new timeout */
diff --git a/include/trace/events/watchdog.h b/include/trace/events/watchdog.h
new file mode 100644
index 000000000000..beb9bb3424c8
--- /dev/null
+++ b/include/trace/events/watchdog.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM watchdog
+
+#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_WATCHDOG_H
+
+#include <linux/watchdog.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(watchdog_template,
+
+ TP_PROTO(struct watchdog_device *wdd, int err),
+
+ TP_ARGS(wdd, err),
+
+ TP_STRUCT__entry(
+ __field(int, id)
+ __field(int, err)
+ ),
+
+ TP_fast_assign(
+ __entry->id = wdd->id;
+ __entry->err = err;
+ ),
+
+ TP_printk("watchdog%d err=%d", __entry->id, __entry->err)
+);
+
+DEFINE_EVENT(watchdog_template, watchdog_start,
+ TP_PROTO(struct watchdog_device *wdd, int err),
+ TP_ARGS(wdd, err));
+
+DEFINE_EVENT(watchdog_template, watchdog_ping,
+ TP_PROTO(struct watchdog_device *wdd, int err),
+ TP_ARGS(wdd, err));
+
+DEFINE_EVENT(watchdog_template, watchdog_stop,
+ TP_PROTO(struct watchdog_device *wdd, int err),
+ TP_ARGS(wdd, err));
+
+TRACE_EVENT(watchdog_set_timeout,
+
+ TP_PROTO(struct watchdog_device *wdd, unsigned int timeout, int err),
+
+ TP_ARGS(wdd, timeout, err),
+
+ TP_STRUCT__entry(
+ __field(int, id)
+ __field(unsigned int, timeout)
+ __field(int, err)
+ ),
+
+ TP_fast_assign(
+ __entry->id = wdd->id;
+ __entry->timeout = timeout;
+ __entry->err = err;
+ ),
+
+ TP_printk("watchdog%d timeout=%u err=%d", __entry->id, __entry->timeout, __entry->err)
+);
+
+#endif /* !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
base-commit: 4fe89d07dcc2804c8b562f6c7896a45643d34b2f
--
2.37.2
