diff mbox series

[V4,17/20] watchdog/dev: Add tracepoints

Message ID e153b772306577bcb3915474ed10eb3dcb228eda.1655368610.git.bristot@kernel.org (mailing list archive)
State Superseded
Headers show
Series The Runtime Verification (RV) interface | expand

Commit Message

Daniel Bristot de Oliveira June 16, 2022, 8:44 a.m. UTC
Add a set of tracepoints, enabling the observability of the watchdog
device interactions with user-space.

The events are:
	watchdog:watchdog_open
	watchdog:watchdog_close
	watchdog:watchdog_start
	watchdog:watchdog_stop
	watchdog:watchdog_set_timeout
	watchdog:watchdog_ping
	watchdog:watchdog_nowayout
	watchdog:watchdog_set_keep_alive
	watchdog:watchdog_keep_alive
	watchdog:watchdog_set_pretimeout
	watchdog:watchdog_pretimeout

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
---
 drivers/watchdog/watchdog_dev.c        |  43 ++++++++++-
 drivers/watchdog/watchdog_pretimeout.c |   2 +
 include/linux/watchdog.h               |   7 +-
 include/trace/events/watchdog.h        | 101 +++++++++++++++++++++++++
 4 files changed, 143 insertions(+), 10 deletions(-)
 create mode 100644 include/trace/events/watchdog.h

Comments

Guenter Roeck June 16, 2022, 1:44 p.m. UTC | #1
On 6/16/22 01:44, Daniel Bristot de Oliveira wrote:
> Add a set of tracepoints, enabling the observability of the watchdog
> device interactions with user-space.
> 
> The events are:
> 	watchdog:watchdog_open
> 	watchdog:watchdog_close
> 	watchdog:watchdog_start
> 	watchdog:watchdog_stop
> 	watchdog:watchdog_set_timeout
> 	watchdog:watchdog_ping
> 	watchdog:watchdog_nowayout
> 	watchdog:watchdog_set_keep_alive
> 	watchdog:watchdog_keep_alive
> 	watchdog:watchdog_set_pretimeout
> 	watchdog:watchdog_pretimeout
> 
> Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Will Deacon <will@kernel.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Marco Elver <elver@google.com>
> Cc: Dmitry Vyukov <dvyukov@google.com>
> Cc: "Paul E. McKenney" <paulmck@kernel.org>
> Cc: Shuah Khan <skhan@linuxfoundation.org>
> Cc: Gabriele Paoloni <gpaoloni@redhat.com>
> Cc: Juri Lelli <juri.lelli@redhat.com>
> Cc: Clark Williams <williams@redhat.com>
> Cc: linux-doc@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-trace-devel@vger.kernel.org
> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
> ---
>   drivers/watchdog/watchdog_dev.c        |  43 ++++++++++-
>   drivers/watchdog/watchdog_pretimeout.c |   2 +
>   include/linux/watchdog.h               |   7 +-
>   include/trace/events/watchdog.h        | 101 +++++++++++++++++++++++++
>   4 files changed, 143 insertions(+), 10 deletions(-)
>   create mode 100644 include/trace/events/watchdog.h
> 
> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
> index 54903f3c851e..2f28dc5ab763 100644
> --- a/drivers/watchdog/watchdog_dev.c
> +++ b/drivers/watchdog/watchdog_dev.c
> @@ -44,6 +44,9 @@
>   #include <linux/watchdog.h>	/* For watchdog specific items */
>   #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
>   
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/watchdog.h>
> +
>   #include "watchdog_core.h"
>   #include "watchdog_pretimeout.h"
>   
> @@ -130,9 +133,11 @@ static inline void watchdog_update_worker(struct watchdog_device *wdd)
>   	if (watchdog_need_worker(wdd)) {
>   		ktime_t t = watchdog_next_keepalive(wdd);
>   
> -		if (t > 0)
> +		if (t > 0) {
>   			hrtimer_start(&wd_data->timer, t,
>   				      HRTIMER_MODE_REL_HARD);
> +			trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t));
> +		}
>   	} else {
>   		hrtimer_cancel(&wd_data->timer);
>   	}
> @@ -141,7 +146,7 @@ static inline void watchdog_update_worker(struct watchdog_device *wdd)
>   static int __watchdog_ping(struct watchdog_device *wdd)
>   {
>   	struct watchdog_core_data *wd_data = wdd->wd_data;
> -	ktime_t earliest_keepalive, now;
> +	ktime_t earliest_keepalive, now, next_keepalive;
>   	int err;
>   
>   	earliest_keepalive = ktime_add(wd_data->last_hw_keepalive,
> @@ -149,14 +154,16 @@ static int __watchdog_ping(struct watchdog_device *wdd)
>   	now = ktime_get();
>   
>   	if (ktime_after(earliest_keepalive, now)) {
> -		hrtimer_start(&wd_data->timer,
> -			      ktime_sub(earliest_keepalive, now),
> +		next_keepalive = ktime_sub(earliest_keepalive, now);
> +		hrtimer_start(&wd_data->timer, next_keepalive,
>   			      HRTIMER_MODE_REL_HARD);
> +		trace_watchdog_set_keep_alive(wdd, ktime_to_ms(next_keepalive));
>   		return 0;
>   	}
>   
>   	wd_data->last_hw_keepalive = now;
>   
> +	trace_watchdog_ping(wdd);
>   	if (wdd->ops->ping)
>   		err = wdd->ops->ping(wdd);  /* ping the watchdog */
>   	else
> @@ -215,6 +222,7 @@ static void watchdog_ping_work(struct kthread_work *work)
>   	wd_data = container_of(work, struct watchdog_core_data, work);
>   
>   	mutex_lock(&wd_data->lock);
> +	trace_watchdog_keep_alive(wd_data->wdd);
>   	if (watchdog_worker_should_ping(wd_data))
>   		__watchdog_ping(wd_data->wdd);
>   	mutex_unlock(&wd_data->lock);
> @@ -250,6 +258,8 @@ static int watchdog_start(struct watchdog_device *wdd)
>   
>   	set_bit(_WDOG_KEEPALIVE, &wd_data->status);
>   
> +	trace_watchdog_start(wdd);
> +
>   	started_at = ktime_get();
>   	if (watchdog_hw_running(wdd) && wdd->ops->ping) {
>   		err = __watchdog_ping(wdd);
> @@ -294,6 +304,7 @@ static int watchdog_stop(struct watchdog_device *wdd)
>   		return -EBUSY;
>   	}
>   
> +	trace_watchdog_stop(wdd);
>   	if (wdd->ops->stop) {
>   		clear_bit(WDOG_HW_RUNNING, &wdd->status);
>   		err = wdd->ops->stop(wdd);
> @@ -367,6 +378,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
>   	if (watchdog_timeout_invalid(wdd, timeout))
>   		return -EINVAL;
>   
> +	trace_watchdog_set_timeout(wdd, timeout);

The driver has no obligation to set the timeout to the
requested value. It might be more valuable to report both
the requested and the actual values.


>   	if (wdd->ops->set_timeout) {
>   		err = wdd->ops->set_timeout(wdd, timeout);
>   	} else {
> @@ -399,6 +411,8 @@ static int watchdog_set_pretimeout(struct watchdog_device *wdd,
>   	if (watchdog_pretimeout_invalid(wdd, timeout))
>   		return -EINVAL;
>   
> +	trace_watchdog_set_pretimeout(wdd, timeout);
> +

Again, the driver has no obligation to set the timeout to the
requested value.

>   	if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT))
>   		err = wdd->ops->set_pretimeout(wdd, timeout);
>   	else
> @@ -430,6 +444,23 @@ static int watchdog_get_timeleft(struct watchdog_device *wdd,
>   	return 0;
>   }
>   
> +/**
> + * watchdog_set_nowayout - set nowaout bit
> + * @wdd:	The watchdog device to set nowayoutbit
> + * @nowayout	A boolean on/off switcher
> + *
> + * If nowayout boolean is true, the nowayout option is set. No action is
> + * taken if nowayout is false.
> + */
> +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
> +{
> +	if (nowayout) {
> +		set_bit(WDOG_NO_WAY_OUT, &wdd->status);
> +		trace_watchdog_nowayout(wdd);
> +	}
> +}
> +EXPORT_SYMBOL(watchdog_set_nowayout);
> +
>   #ifdef CONFIG_WATCHDOG_SYSFS
>   static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
>   				char *buf)
> @@ -861,6 +892,8 @@ static int watchdog_open(struct inode *inode, struct file *file)
>   		goto out_clear;
>   	}
>   
> +	trace_watchdog_open(wdd);
> +
>   	err = watchdog_start(wdd);
>   	if (err < 0)
>   		goto out_mod;
> @@ -883,6 +916,7 @@ static int watchdog_open(struct inode *inode, struct file *file)
>   	return stream_open(inode, file);
>   
>   out_mod:
> +	trace_watchdog_close(wdd);
>   	module_put(wd_data->wdd->ops->owner);
>   out_clear:
>   	clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
> @@ -944,6 +978,7 @@ static int watchdog_release(struct inode *inode, struct file *file)
>   	/* make sure that /dev/watchdog can be re-opened */
>   	clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
>   
> +	trace_watchdog_close(wdd);
>   done:
>   	running = wdd && watchdog_hw_running(wdd);
>   	mutex_unlock(&wd_data->lock);
> diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c
> index 376a495ab80c..58c391ed2205 100644
> --- a/drivers/watchdog/watchdog_pretimeout.c
> +++ b/drivers/watchdog/watchdog_pretimeout.c
> @@ -8,6 +8,7 @@
>   #include <linux/spinlock.h>
>   #include <linux/string.h>
>   #include <linux/watchdog.h>
> +#include <trace/events/watchdog.h>
>   
>   #include "watchdog_core.h"
>   #include "watchdog_pretimeout.h"
> @@ -107,6 +108,7 @@ void watchdog_notify_pretimeout(struct watchdog_device *wdd)
>   		return;
>   	}
>   
> +	trace_watchdog_pretimeout(wdd);
>   	wdd->gov->pretimeout(wdd);
>   	spin_unlock_irqrestore(&pretimeout_lock, flags);
>   }
> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
> index 99660197a36c..11d93407e492 100644
> --- a/include/linux/watchdog.h
> +++ b/include/linux/watchdog.h
> @@ -139,12 +139,7 @@ static inline bool watchdog_hw_running(struct watchdog_device *wdd)
>   	return test_bit(WDOG_HW_RUNNING, &wdd->status);
>   }
>   
> -/* Use the following function to set the nowayout feature */
> -static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
> -{
> -	if (nowayout)
> -		set_bit(WDOG_NO_WAY_OUT, &wdd->status);
> -}
> +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout);
>   
>   /* Use the following function to stop the watchdog on reboot */
>   static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd)
> diff --git a/include/trace/events/watchdog.h b/include/trace/events/watchdog.h
> new file mode 100644
> index 000000000000..145cd6cfaa02
> --- /dev/null
> +++ b/include/trace/events/watchdog.h
> @@ -0,0 +1,101 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM watchdog
> +
> +#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_WATCHDOG_H
> +
> +#include <linux/tracepoint.h>
> +
> +/*
> + * These are all events whose sole argument is the watchdog id.
> + */
> +DECLARE_EVENT_CLASS(dev_operations_template,
> +
> +	TP_PROTO(struct watchdog_device *wdd),
> +
> +	TP_ARGS(wdd),
> +
> +	TP_STRUCT__entry(
> +		__field(__u32, id)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->id = wdd->id;
> +	),
> +
> +	TP_printk("id=%d",
> +		  __entry->id)
> +);
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_open,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_close,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_start,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_stop,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_ping,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_nowayout,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_keep_alive,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +DEFINE_EVENT(dev_operations_template, watchdog_pretimeout,
> +	     TP_PROTO(struct watchdog_device *wdd),
> +	     TP_ARGS(wdd));
> +
> +/*
> + * These are all events with a device ID and a given timeout.
> + */
> +DECLARE_EVENT_CLASS(watchdog_timeout_template,
> +
> +	TP_PROTO(struct watchdog_device *wdd, u64 timeout),
> +
> +	TP_ARGS(wdd, timeout),
> +
> +	TP_STRUCT__entry(
> +		__field(__u32, id)
> +		__field(__u64, timeout)


Why u64 ? timeout is unsigned long.

> +	),
> +
> +	TP_fast_assign(
> +		__entry->id		= wdd->id;
> +		__entry->timeout	= timeout;
> +	),
> +
> +	TP_printk("id=%d timeout=%llus",
> +		  __entry->id, __entry->timeout)
> +);
> +
> +DEFINE_EVENT(watchdog_timeout_template, watchdog_set_timeout,
> +	     TP_PROTO(struct watchdog_device *wdd, u64 timeout),
> +	     TP_ARGS(wdd, timeout));
> +
> +DEFINE_EVENT(watchdog_timeout_template, watchdog_set_pretimeout,
> +	     TP_PROTO(struct watchdog_device *wdd, u64 timeout),
> +	     TP_ARGS(wdd, timeout));
> +
> +DEFINE_EVENT(watchdog_timeout_template, watchdog_set_keep_alive,
> +	     TP_PROTO(struct watchdog_device *wdd, u64 timeout),
> +	     TP_ARGS(wdd, timeout));
> +
> +#endif /* _TRACE_WATCHDOG_H */
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>
Daniel Bristot de Oliveira June 16, 2022, 3:47 p.m. UTC | #2
On 6/16/22 15:44, Guenter Roeck wrote:
> On 6/16/22 01:44, Daniel Bristot de Oliveira wrote:
>> Add a set of tracepoints, enabling the observability of the watchdog
>> device interactions with user-space.
>>
>> The events are:
>>     watchdog:watchdog_open
>>     watchdog:watchdog_close
>>     watchdog:watchdog_start
>>     watchdog:watchdog_stop
>>     watchdog:watchdog_set_timeout
>>     watchdog:watchdog_ping
>>     watchdog:watchdog_nowayout
>>     watchdog:watchdog_set_keep_alive
>>     watchdog:watchdog_keep_alive
>>     watchdog:watchdog_set_pretimeout
>>     watchdog:watchdog_pretimeout
>>
>> Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Jonathan Corbet <corbet@lwn.net>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Marco Elver <elver@google.com>
>> Cc: Dmitry Vyukov <dvyukov@google.com>
>> Cc: "Paul E. McKenney" <paulmck@kernel.org>
>> Cc: Shuah Khan <skhan@linuxfoundation.org>
>> Cc: Gabriele Paoloni <gpaoloni@redhat.com>
>> Cc: Juri Lelli <juri.lelli@redhat.com>
>> Cc: Clark Williams <williams@redhat.com>
>> Cc: linux-doc@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: linux-trace-devel@vger.kernel.org
>> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
>> ---
>>   drivers/watchdog/watchdog_dev.c        |  43 ++++++++++-
>>   drivers/watchdog/watchdog_pretimeout.c |   2 +
>>   include/linux/watchdog.h               |   7 +-
>>   include/trace/events/watchdog.h        | 101 +++++++++++++++++++++++++
>>   4 files changed, 143 insertions(+), 10 deletions(-)
>>   create mode 100644 include/trace/events/watchdog.h
>>
>> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
>> index 54903f3c851e..2f28dc5ab763 100644
>> --- a/drivers/watchdog/watchdog_dev.c
>> +++ b/drivers/watchdog/watchdog_dev.c
>> @@ -44,6 +44,9 @@
>>   #include <linux/watchdog.h>    /* For watchdog specific items */
>>   #include <linux/uaccess.h>    /* For copy_to_user/put_user/... */
>>   +#define CREATE_TRACE_POINTS
>> +#include <trace/events/watchdog.h>
>> +
>>   #include "watchdog_core.h"
>>   #include "watchdog_pretimeout.h"
>>   @@ -130,9 +133,11 @@ static inline void watchdog_update_worker(struct
>> watchdog_device *wdd)
>>       if (watchdog_need_worker(wdd)) {
>>           ktime_t t = watchdog_next_keepalive(wdd);
>>   -        if (t > 0)
>> +        if (t > 0) {
>>               hrtimer_start(&wd_data->timer, t,
>>                         HRTIMER_MODE_REL_HARD);
>> +            trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t));
>> +        }
>>       } else {
>>           hrtimer_cancel(&wd_data->timer);
>>       }
>> @@ -141,7 +146,7 @@ static inline void watchdog_update_worker(struct
>> watchdog_device *wdd)
>>   static int __watchdog_ping(struct watchdog_device *wdd)
>>   {
>>       struct watchdog_core_data *wd_data = wdd->wd_data;
>> -    ktime_t earliest_keepalive, now;
>> +    ktime_t earliest_keepalive, now, next_keepalive;
>>       int err;
>>         earliest_keepalive = ktime_add(wd_data->last_hw_keepalive,
>> @@ -149,14 +154,16 @@ static int __watchdog_ping(struct watchdog_device *wdd)
>>       now = ktime_get();
>>         if (ktime_after(earliest_keepalive, now)) {
>> -        hrtimer_start(&wd_data->timer,
>> -                  ktime_sub(earliest_keepalive, now),
>> +        next_keepalive = ktime_sub(earliest_keepalive, now);
>> +        hrtimer_start(&wd_data->timer, next_keepalive,
>>                     HRTIMER_MODE_REL_HARD);
>> +        trace_watchdog_set_keep_alive(wdd, ktime_to_ms(next_keepalive));
>>           return 0;
>>       }
>>         wd_data->last_hw_keepalive = now;
>>   +    trace_watchdog_ping(wdd);
>>       if (wdd->ops->ping)
>>           err = wdd->ops->ping(wdd);  /* ping the watchdog */
>>       else
>> @@ -215,6 +222,7 @@ static void watchdog_ping_work(struct kthread_work *work)
>>       wd_data = container_of(work, struct watchdog_core_data, work);
>>         mutex_lock(&wd_data->lock);
>> +    trace_watchdog_keep_alive(wd_data->wdd);
>>       if (watchdog_worker_should_ping(wd_data))
>>           __watchdog_ping(wd_data->wdd);
>>       mutex_unlock(&wd_data->lock);
>> @@ -250,6 +258,8 @@ static int watchdog_start(struct watchdog_device *wdd)
>>         set_bit(_WDOG_KEEPALIVE, &wd_data->status);
>>   +    trace_watchdog_start(wdd);
>> +
>>       started_at = ktime_get();
>>       if (watchdog_hw_running(wdd) && wdd->ops->ping) {
>>           err = __watchdog_ping(wdd);
>> @@ -294,6 +304,7 @@ static int watchdog_stop(struct watchdog_device *wdd)
>>           return -EBUSY;
>>       }
>>   +    trace_watchdog_stop(wdd);
>>       if (wdd->ops->stop) {
>>           clear_bit(WDOG_HW_RUNNING, &wdd->status);
>>           err = wdd->ops->stop(wdd);
>> @@ -367,6 +378,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
>>       if (watchdog_timeout_invalid(wdd, timeout))
>>           return -EINVAL;
>>   +    trace_watchdog_set_timeout(wdd, timeout);
> 
> The driver has no obligation to set the timeout to the
> requested value. It might be more valuable to report both
> the requested and the actual values.
> 
>

Ack! how do I get the actual value?

>>       if (wdd->ops->set_timeout) {
>>           err = wdd->ops->set_timeout(wdd, timeout);
>>       } else {
>> @@ -399,6 +411,8 @@ static int watchdog_set_pretimeout(struct watchdog_device
>> *wdd,
>>       if (watchdog_pretimeout_invalid(wdd, timeout))
>>           return -EINVAL;
>>   +    trace_watchdog_set_pretimeout(wdd, timeout);
>> +
> 
> Again, the driver has no obligation to set the timeout to the
> requested value.

/me takes note.

> 
>>       if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT))
>>           err = wdd->ops->set_pretimeout(wdd, timeout);
>>       else
>> @@ -430,6 +444,23 @@ static int watchdog_get_timeleft(struct watchdog_device
>> *wdd,
>>       return 0;
>>   }
>>   +/**
>> + * watchdog_set_nowayout - set nowaout bit
>> + * @wdd:    The watchdog device to set nowayoutbit
>> + * @nowayout    A boolean on/off switcher
>> + *
>> + * If nowayout boolean is true, the nowayout option is set. No action is
>> + * taken if nowayout is false.
>> + */
>> +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
>> +{
>> +    if (nowayout) {
>> +        set_bit(WDOG_NO_WAY_OUT, &wdd->status);
>> +        trace_watchdog_nowayout(wdd);
>> +    }
>> +}
>> +EXPORT_SYMBOL(watchdog_set_nowayout);
>> +
>>   #ifdef CONFIG_WATCHDOG_SYSFS
>>   static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
>>                   char *buf)
>> @@ -861,6 +892,8 @@ static int watchdog_open(struct inode *inode, struct file
>> *file)
>>           goto out_clear;
>>       }
>>   +    trace_watchdog_open(wdd);
>> +
>>       err = watchdog_start(wdd);
>>       if (err < 0)
>>           goto out_mod;
>> @@ -883,6 +916,7 @@ static int watchdog_open(struct inode *inode, struct file
>> *file)
>>       return stream_open(inode, file);
>>     out_mod:
>> +    trace_watchdog_close(wdd);
>>       module_put(wd_data->wdd->ops->owner);
>>   out_clear:
>>       clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
>> @@ -944,6 +978,7 @@ static int watchdog_release(struct inode *inode, struct
>> file *file)
>>       /* make sure that /dev/watchdog can be re-opened */
>>       clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
>>   +    trace_watchdog_close(wdd);
>>   done:
>>       running = wdd && watchdog_hw_running(wdd);
>>       mutex_unlock(&wd_data->lock);
>> diff --git a/drivers/watchdog/watchdog_pretimeout.c
>> b/drivers/watchdog/watchdog_pretimeout.c
>> index 376a495ab80c..58c391ed2205 100644
>> --- a/drivers/watchdog/watchdog_pretimeout.c
>> +++ b/drivers/watchdog/watchdog_pretimeout.c
>> @@ -8,6 +8,7 @@
>>   #include <linux/spinlock.h>
>>   #include <linux/string.h>
>>   #include <linux/watchdog.h>
>> +#include <trace/events/watchdog.h>
>>     #include "watchdog_core.h"
>>   #include "watchdog_pretimeout.h"
>> @@ -107,6 +108,7 @@ void watchdog_notify_pretimeout(struct watchdog_device *wdd)
>>           return;
>>       }
>>   +    trace_watchdog_pretimeout(wdd);
>>       wdd->gov->pretimeout(wdd);
>>       spin_unlock_irqrestore(&pretimeout_lock, flags);
>>   }
>> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
>> index 99660197a36c..11d93407e492 100644
>> --- a/include/linux/watchdog.h
>> +++ b/include/linux/watchdog.h
>> @@ -139,12 +139,7 @@ static inline bool watchdog_hw_running(struct
>> watchdog_device *wdd)
>>       return test_bit(WDOG_HW_RUNNING, &wdd->status);
>>   }
>>   -/* Use the following function to set the nowayout feature */
>> -static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool
>> nowayout)
>> -{
>> -    if (nowayout)
>> -        set_bit(WDOG_NO_WAY_OUT, &wdd->status);
>> -}
>> +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout);
>>     /* Use the following function to stop the watchdog on reboot */
>>   static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd)
>> diff --git a/include/trace/events/watchdog.h b/include/trace/events/watchdog.h
>> new file mode 100644
>> index 000000000000..145cd6cfaa02
>> --- /dev/null
>> +++ b/include/trace/events/watchdog.h
>> @@ -0,0 +1,101 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#undef TRACE_SYSTEM
>> +#define TRACE_SYSTEM watchdog
>> +
>> +#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ)
>> +#define _TRACE_WATCHDOG_H
>> +
>> +#include <linux/tracepoint.h>
>> +
>> +/*
>> + * These are all events whose sole argument is the watchdog id.
>> + */
>> +DECLARE_EVENT_CLASS(dev_operations_template,
>> +
>> +    TP_PROTO(struct watchdog_device *wdd),
>> +
>> +    TP_ARGS(wdd),
>> +
>> +    TP_STRUCT__entry(
>> +        __field(__u32, id)
>> +    ),
>> +
>> +    TP_fast_assign(
>> +        __entry->id = wdd->id;
>> +    ),
>> +
>> +    TP_printk("id=%d",
>> +          __entry->id)
>> +);
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_open,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_close,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_start,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_stop,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_ping,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_nowayout,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_keep_alive,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +DEFINE_EVENT(dev_operations_template, watchdog_pretimeout,
>> +         TP_PROTO(struct watchdog_device *wdd),
>> +         TP_ARGS(wdd));
>> +
>> +/*
>> + * These are all events with a device ID and a given timeout.
>> + */
>> +DECLARE_EVENT_CLASS(watchdog_timeout_template,
>> +
>> +    TP_PROTO(struct watchdog_device *wdd, u64 timeout),
>> +
>> +    TP_ARGS(wdd, timeout),
>> +
>> +    TP_STRUCT__entry(
>> +        __field(__u32, id)
>> +        __field(__u64, timeout)
> 
> 
> Why u64 ? timeout is unsigned long.

ack! I will change it. (I am seeing unsigned int, am I missing something?).

Thanks!
-- Daniel
Guenter Roeck June 16, 2022, 11:55 p.m. UTC | #3
On 6/16/22 08:47, Daniel Bristot de Oliveira wrote:
> On 6/16/22 15:44, Guenter Roeck wrote:
>> On 6/16/22 01:44, Daniel Bristot de Oliveira wrote:
>>> Add a set of tracepoints, enabling the observability of the watchdog
>>> device interactions with user-space.
>>>
>>> The events are:
>>>      watchdog:watchdog_open
>>>      watchdog:watchdog_close
>>>      watchdog:watchdog_start
>>>      watchdog:watchdog_stop
>>>      watchdog:watchdog_set_timeout
>>>      watchdog:watchdog_ping
>>>      watchdog:watchdog_nowayout
>>>      watchdog:watchdog_set_keep_alive
>>>      watchdog:watchdog_keep_alive
>>>      watchdog:watchdog_set_pretimeout
>>>      watchdog:watchdog_pretimeout
>>>
>>> Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
>>> Cc: Guenter Roeck <linux@roeck-us.net>
>>> Cc: Jonathan Corbet <corbet@lwn.net>
>>> Cc: Steven Rostedt <rostedt@goodmis.org>
>>> Cc: Ingo Molnar <mingo@redhat.com>
>>> Cc: Thomas Gleixner <tglx@linutronix.de>
>>> Cc: Peter Zijlstra <peterz@infradead.org>
>>> Cc: Will Deacon <will@kernel.org>
>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>> Cc: Marco Elver <elver@google.com>
>>> Cc: Dmitry Vyukov <dvyukov@google.com>
>>> Cc: "Paul E. McKenney" <paulmck@kernel.org>
>>> Cc: Shuah Khan <skhan@linuxfoundation.org>
>>> Cc: Gabriele Paoloni <gpaoloni@redhat.com>
>>> Cc: Juri Lelli <juri.lelli@redhat.com>
>>> Cc: Clark Williams <williams@redhat.com>
>>> Cc: linux-doc@vger.kernel.org
>>> Cc: linux-kernel@vger.kernel.org
>>> Cc: linux-trace-devel@vger.kernel.org
>>> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
>>> ---
>>>    drivers/watchdog/watchdog_dev.c        |  43 ++++++++++-
>>>    drivers/watchdog/watchdog_pretimeout.c |   2 +
>>>    include/linux/watchdog.h               |   7 +-
>>>    include/trace/events/watchdog.h        | 101 +++++++++++++++++++++++++
>>>    4 files changed, 143 insertions(+), 10 deletions(-)
>>>    create mode 100644 include/trace/events/watchdog.h
>>>
>>> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
>>> index 54903f3c851e..2f28dc5ab763 100644
>>> --- a/drivers/watchdog/watchdog_dev.c
>>> +++ b/drivers/watchdog/watchdog_dev.c
>>> @@ -44,6 +44,9 @@
>>>    #include <linux/watchdog.h>    /* For watchdog specific items */
>>>    #include <linux/uaccess.h>    /* For copy_to_user/put_user/... */
>>>    +#define CREATE_TRACE_POINTS
>>> +#include <trace/events/watchdog.h>
>>> +
>>>    #include "watchdog_core.h"
>>>    #include "watchdog_pretimeout.h"
>>>    @@ -130,9 +133,11 @@ static inline void watchdog_update_worker(struct
>>> watchdog_device *wdd)
>>>        if (watchdog_need_worker(wdd)) {
>>>            ktime_t t = watchdog_next_keepalive(wdd);
>>>    -        if (t > 0)
>>> +        if (t > 0) {
>>>                hrtimer_start(&wd_data->timer, t,
>>>                          HRTIMER_MODE_REL_HARD);
>>> +            trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t));
>>> +        }
>>>        } else {
>>>            hrtimer_cancel(&wd_data->timer);
>>>        }
>>> @@ -141,7 +146,7 @@ static inline void watchdog_update_worker(struct
>>> watchdog_device *wdd)
>>>    static int __watchdog_ping(struct watchdog_device *wdd)
>>>    {
>>>        struct watchdog_core_data *wd_data = wdd->wd_data;
>>> -    ktime_t earliest_keepalive, now;
>>> +    ktime_t earliest_keepalive, now, next_keepalive;
>>>        int err;
>>>          earliest_keepalive = ktime_add(wd_data->last_hw_keepalive,
>>> @@ -149,14 +154,16 @@ static int __watchdog_ping(struct watchdog_device *wdd)
>>>        now = ktime_get();
>>>          if (ktime_after(earliest_keepalive, now)) {
>>> -        hrtimer_start(&wd_data->timer,
>>> -                  ktime_sub(earliest_keepalive, now),
>>> +        next_keepalive = ktime_sub(earliest_keepalive, now);
>>> +        hrtimer_start(&wd_data->timer, next_keepalive,
>>>                      HRTIMER_MODE_REL_HARD);
>>> +        trace_watchdog_set_keep_alive(wdd, ktime_to_ms(next_keepalive));
>>>            return 0;
>>>        }
>>>          wd_data->last_hw_keepalive = now;
>>>    +    trace_watchdog_ping(wdd);
>>>        if (wdd->ops->ping)
>>>            err = wdd->ops->ping(wdd);  /* ping the watchdog */
>>>        else
>>> @@ -215,6 +222,7 @@ static void watchdog_ping_work(struct kthread_work *work)
>>>        wd_data = container_of(work, struct watchdog_core_data, work);
>>>          mutex_lock(&wd_data->lock);
>>> +    trace_watchdog_keep_alive(wd_data->wdd);
>>>        if (watchdog_worker_should_ping(wd_data))
>>>            __watchdog_ping(wd_data->wdd);
>>>        mutex_unlock(&wd_data->lock);
>>> @@ -250,6 +258,8 @@ static int watchdog_start(struct watchdog_device *wdd)
>>>          set_bit(_WDOG_KEEPALIVE, &wd_data->status);
>>>    +    trace_watchdog_start(wdd);
>>> +
>>>        started_at = ktime_get();
>>>        if (watchdog_hw_running(wdd) && wdd->ops->ping) {
>>>            err = __watchdog_ping(wdd);
>>> @@ -294,6 +304,7 @@ static int watchdog_stop(struct watchdog_device *wdd)
>>>            return -EBUSY;
>>>        }
>>>    +    trace_watchdog_stop(wdd);
>>>        if (wdd->ops->stop) {
>>>            clear_bit(WDOG_HW_RUNNING, &wdd->status);
>>>            err = wdd->ops->stop(wdd);
>>> @@ -367,6 +378,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
>>>        if (watchdog_timeout_invalid(wdd, timeout))
>>>            return -EINVAL;
>>>    +    trace_watchdog_set_timeout(wdd, timeout);
>>
>> The driver has no obligation to set the timeout to the
>> requested value. It might be more valuable to report both
>> the requested and the actual values.
>>
>>
> 
> Ack! how do I get the actual value?
> 
Read it from the data structure after the driver function returned.

>>>        if (wdd->ops->set_timeout) {
>>>            err = wdd->ops->set_timeout(wdd, timeout);
>>>        } else {
>>> @@ -399,6 +411,8 @@ static int watchdog_set_pretimeout(struct watchdog_device
>>> *wdd,
>>>        if (watchdog_pretimeout_invalid(wdd, timeout))
>>>            return -EINVAL;
>>>    +    trace_watchdog_set_pretimeout(wdd, timeout);
>>> +
>>
>> Again, the driver has no obligation to set the timeout to the
>> requested value.
> 
> /me takes note.
> 
>>
>>>        if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT))
>>>            err = wdd->ops->set_pretimeout(wdd, timeout);
>>>        else
>>> @@ -430,6 +444,23 @@ static int watchdog_get_timeleft(struct watchdog_device
>>> *wdd,
>>>        return 0;
>>>    }
>>>    +/**
>>> + * watchdog_set_nowayout - set nowaout bit
>>> + * @wdd:    The watchdog device to set nowayoutbit
>>> + * @nowayout    A boolean on/off switcher
>>> + *
>>> + * If nowayout boolean is true, the nowayout option is set. No action is
>>> + * taken if nowayout is false.
>>> + */
>>> +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
>>> +{
>>> +    if (nowayout) {
>>> +        set_bit(WDOG_NO_WAY_OUT, &wdd->status);
>>> +        trace_watchdog_nowayout(wdd);
>>> +    }
>>> +}
>>> +EXPORT_SYMBOL(watchdog_set_nowayout);
>>> +
>>>    #ifdef CONFIG_WATCHDOG_SYSFS
>>>    static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
>>>                    char *buf)
>>> @@ -861,6 +892,8 @@ static int watchdog_open(struct inode *inode, struct file
>>> *file)
>>>            goto out_clear;
>>>        }
>>>    +    trace_watchdog_open(wdd);
>>> +
>>>        err = watchdog_start(wdd);
>>>        if (err < 0)
>>>            goto out_mod;
>>> @@ -883,6 +916,7 @@ static int watchdog_open(struct inode *inode, struct file
>>> *file)
>>>        return stream_open(inode, file);
>>>      out_mod:
>>> +    trace_watchdog_close(wdd);
>>>        module_put(wd_data->wdd->ops->owner);
>>>    out_clear:
>>>        clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
>>> @@ -944,6 +978,7 @@ static int watchdog_release(struct inode *inode, struct
>>> file *file)
>>>        /* make sure that /dev/watchdog can be re-opened */
>>>        clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
>>>    +    trace_watchdog_close(wdd);
>>>    done:
>>>        running = wdd && watchdog_hw_running(wdd);
>>>        mutex_unlock(&wd_data->lock);
>>> diff --git a/drivers/watchdog/watchdog_pretimeout.c
>>> b/drivers/watchdog/watchdog_pretimeout.c
>>> index 376a495ab80c..58c391ed2205 100644
>>> --- a/drivers/watchdog/watchdog_pretimeout.c
>>> +++ b/drivers/watchdog/watchdog_pretimeout.c
>>> @@ -8,6 +8,7 @@
>>>    #include <linux/spinlock.h>
>>>    #include <linux/string.h>
>>>    #include <linux/watchdog.h>
>>> +#include <trace/events/watchdog.h>
>>>      #include "watchdog_core.h"
>>>    #include "watchdog_pretimeout.h"
>>> @@ -107,6 +108,7 @@ void watchdog_notify_pretimeout(struct watchdog_device *wdd)
>>>            return;
>>>        }
>>>    +    trace_watchdog_pretimeout(wdd);
>>>        wdd->gov->pretimeout(wdd);
>>>        spin_unlock_irqrestore(&pretimeout_lock, flags);
>>>    }
>>> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
>>> index 99660197a36c..11d93407e492 100644
>>> --- a/include/linux/watchdog.h
>>> +++ b/include/linux/watchdog.h
>>> @@ -139,12 +139,7 @@ static inline bool watchdog_hw_running(struct
>>> watchdog_device *wdd)
>>>        return test_bit(WDOG_HW_RUNNING, &wdd->status);
>>>    }
>>>    -/* Use the following function to set the nowayout feature */
>>> -static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool
>>> nowayout)
>>> -{
>>> -    if (nowayout)
>>> -        set_bit(WDOG_NO_WAY_OUT, &wdd->status);
>>> -}
>>> +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout);
>>>      /* Use the following function to stop the watchdog on reboot */
>>>    static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd)
>>> diff --git a/include/trace/events/watchdog.h b/include/trace/events/watchdog.h
>>> new file mode 100644
>>> index 000000000000..145cd6cfaa02
>>> --- /dev/null
>>> +++ b/include/trace/events/watchdog.h
>>> @@ -0,0 +1,101 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +#undef TRACE_SYSTEM
>>> +#define TRACE_SYSTEM watchdog
>>> +
>>> +#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ)
>>> +#define _TRACE_WATCHDOG_H
>>> +
>>> +#include <linux/tracepoint.h>
>>> +
>>> +/*
>>> + * These are all events whose sole argument is the watchdog id.
>>> + */
>>> +DECLARE_EVENT_CLASS(dev_operations_template,
>>> +
>>> +    TP_PROTO(struct watchdog_device *wdd),
>>> +
>>> +    TP_ARGS(wdd),
>>> +
>>> +    TP_STRUCT__entry(
>>> +        __field(__u32, id)
>>> +    ),
>>> +
>>> +    TP_fast_assign(
>>> +        __entry->id = wdd->id;
>>> +    ),
>>> +
>>> +    TP_printk("id=%d",
>>> +          __entry->id)
>>> +);
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_open,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_close,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_start,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_stop,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_ping,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_nowayout,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_keep_alive,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +DEFINE_EVENT(dev_operations_template, watchdog_pretimeout,
>>> +         TP_PROTO(struct watchdog_device *wdd),
>>> +         TP_ARGS(wdd));
>>> +
>>> +/*
>>> + * These are all events with a device ID and a given timeout.
>>> + */
>>> +DECLARE_EVENT_CLASS(watchdog_timeout_template,
>>> +
>>> +    TP_PROTO(struct watchdog_device *wdd, u64 timeout),
>>> +
>>> +    TP_ARGS(wdd, timeout),
>>> +
>>> +    TP_STRUCT__entry(
>>> +        __field(__u32, id)
>>> +        __field(__u64, timeout)
>>
>>
>> Why u64 ? timeout is unsigned long.
> 
> ack! I will change it. (I am seeing unsigned int, am I missing something?).

Yes, you are correct.

Guenter
Daniel Bristot de Oliveira June 17, 2022, 4:16 p.m. UTC | #4
On 6/17/22 01:55, Guenter Roeck wrote:
> On 6/16/22 08:47, Daniel Bristot de Oliveira wrote:
>> On 6/16/22 15:44, Guenter Roeck wrote:
>>> On 6/16/22 01:44, Daniel Bristot de Oliveira wrote:
>>>> Add a set of tracepoints, enabling the observability of the watchdog
>>>> device interactions with user-space.
>>>>
>>>> The events are:
>>>>      watchdog:watchdog_open
>>>>      watchdog:watchdog_close
>>>>      watchdog:watchdog_start
>>>>      watchdog:watchdog_stop
>>>>      watchdog:watchdog_set_timeout
>>>>      watchdog:watchdog_ping
>>>>      watchdog:watchdog_nowayout
>>>>      watchdog:watchdog_set_keep_alive
>>>>      watchdog:watchdog_keep_alive
>>>>      watchdog:watchdog_set_pretimeout
>>>>      watchdog:watchdog_pretimeout
>>>>
>>>> Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
>>>> Cc: Guenter Roeck <linux@roeck-us.net>
>>>> Cc: Jonathan Corbet <corbet@lwn.net>
>>>> Cc: Steven Rostedt <rostedt@goodmis.org>
>>>> Cc: Ingo Molnar <mingo@redhat.com>
>>>> Cc: Thomas Gleixner <tglx@linutronix.de>
>>>> Cc: Peter Zijlstra <peterz@infradead.org>
>>>> Cc: Will Deacon <will@kernel.org>
>>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>>> Cc: Marco Elver <elver@google.com>
>>>> Cc: Dmitry Vyukov <dvyukov@google.com>
>>>> Cc: "Paul E. McKenney" <paulmck@kernel.org>
>>>> Cc: Shuah Khan <skhan@linuxfoundation.org>
>>>> Cc: Gabriele Paoloni <gpaoloni@redhat.com>
>>>> Cc: Juri Lelli <juri.lelli@redhat.com>
>>>> Cc: Clark Williams <williams@redhat.com>
>>>> Cc: linux-doc@vger.kernel.org
>>>> Cc: linux-kernel@vger.kernel.org
>>>> Cc: linux-trace-devel@vger.kernel.org
>>>> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
>>>> ---
>>>>    drivers/watchdog/watchdog_dev.c        |  43 ++++++++++-
>>>>    drivers/watchdog/watchdog_pretimeout.c |   2 +
>>>>    include/linux/watchdog.h               |   7 +-
>>>>    include/trace/events/watchdog.h        | 101 +++++++++++++++++++++++++
>>>>    4 files changed, 143 insertions(+), 10 deletions(-)
>>>>    create mode 100644 include/trace/events/watchdog.h
>>>>
>>>> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
>>>> index 54903f3c851e..2f28dc5ab763 100644
>>>> --- a/drivers/watchdog/watchdog_dev.c
>>>> +++ b/drivers/watchdog/watchdog_dev.c
>>>> @@ -44,6 +44,9 @@
>>>>    #include <linux/watchdog.h>    /* For watchdog specific items */
>>>>    #include <linux/uaccess.h>    /* For copy_to_user/put_user/... */
>>>>    +#define CREATE_TRACE_POINTS
>>>> +#include <trace/events/watchdog.h>
>>>> +
>>>>    #include "watchdog_core.h"
>>>>    #include "watchdog_pretimeout.h"
>>>>    @@ -130,9 +133,11 @@ static inline void watchdog_update_worker(struct
>>>> watchdog_device *wdd)
>>>>        if (watchdog_need_worker(wdd)) {
>>>>            ktime_t t = watchdog_next_keepalive(wdd);
>>>>    -        if (t > 0)
>>>> +        if (t > 0) {
>>>>                hrtimer_start(&wd_data->timer, t,
>>>>                          HRTIMER_MODE_REL_HARD);
>>>> +            trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t));
>>>> +        }
>>>>        } else {
>>>>            hrtimer_cancel(&wd_data->timer);
>>>>        }
>>>> @@ -141,7 +146,7 @@ static inline void watchdog_update_worker(struct
>>>> watchdog_device *wdd)
>>>>    static int __watchdog_ping(struct watchdog_device *wdd)
>>>>    {
>>>>        struct watchdog_core_data *wd_data = wdd->wd_data;
>>>> -    ktime_t earliest_keepalive, now;
>>>> +    ktime_t earliest_keepalive, now, next_keepalive;
>>>>        int err;
>>>>          earliest_keepalive = ktime_add(wd_data->last_hw_keepalive,
>>>> @@ -149,14 +154,16 @@ static int __watchdog_ping(struct watchdog_device *wdd)
>>>>        now = ktime_get();
>>>>          if (ktime_after(earliest_keepalive, now)) {
>>>> -        hrtimer_start(&wd_data->timer,
>>>> -                  ktime_sub(earliest_keepalive, now),
>>>> +        next_keepalive = ktime_sub(earliest_keepalive, now);
>>>> +        hrtimer_start(&wd_data->timer, next_keepalive,
>>>>                      HRTIMER_MODE_REL_HARD);
>>>> +        trace_watchdog_set_keep_alive(wdd, ktime_to_ms(next_keepalive));
>>>>            return 0;
>>>>        }
>>>>          wd_data->last_hw_keepalive = now;
>>>>    +    trace_watchdog_ping(wdd);
>>>>        if (wdd->ops->ping)
>>>>            err = wdd->ops->ping(wdd);  /* ping the watchdog */
>>>>        else
>>>> @@ -215,6 +222,7 @@ static void watchdog_ping_work(struct kthread_work *work)
>>>>        wd_data = container_of(work, struct watchdog_core_data, work);
>>>>          mutex_lock(&wd_data->lock);
>>>> +    trace_watchdog_keep_alive(wd_data->wdd);
>>>>        if (watchdog_worker_should_ping(wd_data))
>>>>            __watchdog_ping(wd_data->wdd);
>>>>        mutex_unlock(&wd_data->lock);
>>>> @@ -250,6 +258,8 @@ static int watchdog_start(struct watchdog_device *wdd)
>>>>          set_bit(_WDOG_KEEPALIVE, &wd_data->status);
>>>>    +    trace_watchdog_start(wdd);
>>>> +
>>>>        started_at = ktime_get();
>>>>        if (watchdog_hw_running(wdd) && wdd->ops->ping) {
>>>>            err = __watchdog_ping(wdd);
>>>> @@ -294,6 +304,7 @@ static int watchdog_stop(struct watchdog_device *wdd)
>>>>            return -EBUSY;
>>>>        }
>>>>    +    trace_watchdog_stop(wdd);
>>>>        if (wdd->ops->stop) {
>>>>            clear_bit(WDOG_HW_RUNNING, &wdd->status);
>>>>            err = wdd->ops->stop(wdd);
>>>> @@ -367,6 +378,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
>>>>
>>>>        if (watchdog_timeout_invalid(wdd, timeout))
>>>>            return -EINVAL;
>>>>    +    trace_watchdog_set_timeout(wdd, timeout);
>>>
>>> The driver has no obligation to set the timeout to the
>>> requested value. It might be more valuable to report both
>>> the requested and the actual values.
>>>
>>>
>>
>> Ack! how do I get the actual value?
>>
> Read it from the data structure after the driver function returned.

Got it! I will add this field too.

-- Daniel
Daniel Bristot de Oliveira July 13, 2022, 6:49 p.m. UTC | #5
On 6/17/22 01:55, Guenter Roeck wrote:
>>
>> ack! I will change it. (I am seeing unsigned int, am I missing something?).
> 
> Yes, you are correct.

Fixed!

-- Daniel
diff mbox series

Patch

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 54903f3c851e..2f28dc5ab763 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -44,6 +44,9 @@ 
 #include <linux/watchdog.h>	/* For watchdog specific items */
 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/watchdog.h>
+
 #include "watchdog_core.h"
 #include "watchdog_pretimeout.h"
 
@@ -130,9 +133,11 @@  static inline void watchdog_update_worker(struct watchdog_device *wdd)
 	if (watchdog_need_worker(wdd)) {
 		ktime_t t = watchdog_next_keepalive(wdd);
 
-		if (t > 0)
+		if (t > 0) {
 			hrtimer_start(&wd_data->timer, t,
 				      HRTIMER_MODE_REL_HARD);
+			trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t));
+		}
 	} else {
 		hrtimer_cancel(&wd_data->timer);
 	}
@@ -141,7 +146,7 @@  static inline void watchdog_update_worker(struct watchdog_device *wdd)
 static int __watchdog_ping(struct watchdog_device *wdd)
 {
 	struct watchdog_core_data *wd_data = wdd->wd_data;
-	ktime_t earliest_keepalive, now;
+	ktime_t earliest_keepalive, now, next_keepalive;
 	int err;
 
 	earliest_keepalive = ktime_add(wd_data->last_hw_keepalive,
@@ -149,14 +154,16 @@  static int __watchdog_ping(struct watchdog_device *wdd)
 	now = ktime_get();
 
 	if (ktime_after(earliest_keepalive, now)) {
-		hrtimer_start(&wd_data->timer,
-			      ktime_sub(earliest_keepalive, now),
+		next_keepalive = ktime_sub(earliest_keepalive, now);
+		hrtimer_start(&wd_data->timer, next_keepalive,
 			      HRTIMER_MODE_REL_HARD);
+		trace_watchdog_set_keep_alive(wdd, ktime_to_ms(next_keepalive));
 		return 0;
 	}
 
 	wd_data->last_hw_keepalive = now;
 
+	trace_watchdog_ping(wdd);
 	if (wdd->ops->ping)
 		err = wdd->ops->ping(wdd);  /* ping the watchdog */
 	else
@@ -215,6 +222,7 @@  static void watchdog_ping_work(struct kthread_work *work)
 	wd_data = container_of(work, struct watchdog_core_data, work);
 
 	mutex_lock(&wd_data->lock);
+	trace_watchdog_keep_alive(wd_data->wdd);
 	if (watchdog_worker_should_ping(wd_data))
 		__watchdog_ping(wd_data->wdd);
 	mutex_unlock(&wd_data->lock);
@@ -250,6 +258,8 @@  static int watchdog_start(struct watchdog_device *wdd)
 
 	set_bit(_WDOG_KEEPALIVE, &wd_data->status);
 
+	trace_watchdog_start(wdd);
+
 	started_at = ktime_get();
 	if (watchdog_hw_running(wdd) && wdd->ops->ping) {
 		err = __watchdog_ping(wdd);
@@ -294,6 +304,7 @@  static int watchdog_stop(struct watchdog_device *wdd)
 		return -EBUSY;
 	}
 
+	trace_watchdog_stop(wdd);
 	if (wdd->ops->stop) {
 		clear_bit(WDOG_HW_RUNNING, &wdd->status);
 		err = wdd->ops->stop(wdd);
@@ -367,6 +378,7 @@  static int watchdog_set_timeout(struct watchdog_device *wdd,
 	if (watchdog_timeout_invalid(wdd, timeout))
 		return -EINVAL;
 
+	trace_watchdog_set_timeout(wdd, timeout);
 	if (wdd->ops->set_timeout) {
 		err = wdd->ops->set_timeout(wdd, timeout);
 	} else {
@@ -399,6 +411,8 @@  static int watchdog_set_pretimeout(struct watchdog_device *wdd,
 	if (watchdog_pretimeout_invalid(wdd, timeout))
 		return -EINVAL;
 
+	trace_watchdog_set_pretimeout(wdd, timeout);
+
 	if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT))
 		err = wdd->ops->set_pretimeout(wdd, timeout);
 	else
@@ -430,6 +444,23 @@  static int watchdog_get_timeleft(struct watchdog_device *wdd,
 	return 0;
 }
 
+/**
+ * watchdog_set_nowayout - set nowaout bit
+ * @wdd:	The watchdog device to set nowayoutbit
+ * @nowayout	A boolean on/off switcher
+ *
+ * If nowayout boolean is true, the nowayout option is set. No action is
+ * taken if nowayout is false.
+ */
+void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
+{
+	if (nowayout) {
+		set_bit(WDOG_NO_WAY_OUT, &wdd->status);
+		trace_watchdog_nowayout(wdd);
+	}
+}
+EXPORT_SYMBOL(watchdog_set_nowayout);
+
 #ifdef CONFIG_WATCHDOG_SYSFS
 static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
 				char *buf)
@@ -861,6 +892,8 @@  static int watchdog_open(struct inode *inode, struct file *file)
 		goto out_clear;
 	}
 
+	trace_watchdog_open(wdd);
+
 	err = watchdog_start(wdd);
 	if (err < 0)
 		goto out_mod;
@@ -883,6 +916,7 @@  static int watchdog_open(struct inode *inode, struct file *file)
 	return stream_open(inode, file);
 
 out_mod:
+	trace_watchdog_close(wdd);
 	module_put(wd_data->wdd->ops->owner);
 out_clear:
 	clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
@@ -944,6 +978,7 @@  static int watchdog_release(struct inode *inode, struct file *file)
 	/* make sure that /dev/watchdog can be re-opened */
 	clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
 
+	trace_watchdog_close(wdd);
 done:
 	running = wdd && watchdog_hw_running(wdd);
 	mutex_unlock(&wd_data->lock);
diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c
index 376a495ab80c..58c391ed2205 100644
--- a/drivers/watchdog/watchdog_pretimeout.c
+++ b/drivers/watchdog/watchdog_pretimeout.c
@@ -8,6 +8,7 @@ 
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/watchdog.h>
+#include <trace/events/watchdog.h>
 
 #include "watchdog_core.h"
 #include "watchdog_pretimeout.h"
@@ -107,6 +108,7 @@  void watchdog_notify_pretimeout(struct watchdog_device *wdd)
 		return;
 	}
 
+	trace_watchdog_pretimeout(wdd);
 	wdd->gov->pretimeout(wdd);
 	spin_unlock_irqrestore(&pretimeout_lock, flags);
 }
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 99660197a36c..11d93407e492 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -139,12 +139,7 @@  static inline bool watchdog_hw_running(struct watchdog_device *wdd)
 	return test_bit(WDOG_HW_RUNNING, &wdd->status);
 }
 
-/* Use the following function to set the nowayout feature */
-static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
-{
-	if (nowayout)
-		set_bit(WDOG_NO_WAY_OUT, &wdd->status);
-}
+void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout);
 
 /* Use the following function to stop the watchdog on reboot */
 static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd)
diff --git a/include/trace/events/watchdog.h b/include/trace/events/watchdog.h
new file mode 100644
index 000000000000..145cd6cfaa02
--- /dev/null
+++ b/include/trace/events/watchdog.h
@@ -0,0 +1,101 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM watchdog
+
+#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_WATCHDOG_H
+
+#include <linux/tracepoint.h>
+
+/*
+ * These are all events whose sole argument is the watchdog id.
+ */
+DECLARE_EVENT_CLASS(dev_operations_template,
+
+	TP_PROTO(struct watchdog_device *wdd),
+
+	TP_ARGS(wdd),
+
+	TP_STRUCT__entry(
+		__field(__u32, id)
+	),
+
+	TP_fast_assign(
+		__entry->id = wdd->id;
+	),
+
+	TP_printk("id=%d",
+		  __entry->id)
+);
+
+DEFINE_EVENT(dev_operations_template, watchdog_open,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_close,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_start,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_stop,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_ping,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_nowayout,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_keep_alive,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+DEFINE_EVENT(dev_operations_template, watchdog_pretimeout,
+	     TP_PROTO(struct watchdog_device *wdd),
+	     TP_ARGS(wdd));
+
+/*
+ * These are all events with a device ID and a given timeout.
+ */
+DECLARE_EVENT_CLASS(watchdog_timeout_template,
+
+	TP_PROTO(struct watchdog_device *wdd, u64 timeout),
+
+	TP_ARGS(wdd, timeout),
+
+	TP_STRUCT__entry(
+		__field(__u32, id)
+		__field(__u64, timeout)
+	),
+
+	TP_fast_assign(
+		__entry->id		= wdd->id;
+		__entry->timeout	= timeout;
+	),
+
+	TP_printk("id=%d timeout=%llus",
+		  __entry->id, __entry->timeout)
+);
+
+DEFINE_EVENT(watchdog_timeout_template, watchdog_set_timeout,
+	     TP_PROTO(struct watchdog_device *wdd, u64 timeout),
+	     TP_ARGS(wdd, timeout));
+
+DEFINE_EVENT(watchdog_timeout_template, watchdog_set_pretimeout,
+	     TP_PROTO(struct watchdog_device *wdd, u64 timeout),
+	     TP_ARGS(wdd, timeout));
+
+DEFINE_EVENT(watchdog_timeout_template, watchdog_set_keep_alive,
+	     TP_PROTO(struct watchdog_device *wdd, u64 timeout),
+	     TP_ARGS(wdd, timeout));
+
+#endif /* _TRACE_WATCHDOG_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>