Re: PM / Suspend: Print wall time at suspend entry and exit

[Pavel Machek]

On Mon 2017-06-05 12:31:14, Mark Salyzyn wrote:
> Permits power state and battery life diagnosis.
> 
> Signed-off-by: Todd Poynor <toddpoynor@xxxxxxxxxx>
> Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx>

I don't particulary like it (RTC is slow on PC class machines), but I
guess the information is useful.

Acked-by: Pavel Machek <pavel@xxxxxx>

> ---
>  kernel/power/suspend.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
> index c0248c74d6d4..464175f04bc5 100644
> --- a/kernel/power/suspend.c
> +++ b/kernel/power/suspend.c
> @@ -26,6 +26,7 @@
>  #include <linux/suspend.h>
>  #include <linux/syscore_ops.h>
>  #include <linux/ftrace.h>
> +#include <linux/rtc.h>
>  #include <trace/events/power.h>
>  #include <linux/compiler.h>
>  #include <linux/moduleparam.h>
> @@ -563,6 +564,18 @@ static int enter_state(suspend_state_t state)
>  	return error;
>  }
>  
> +static void pm_suspend_marker(char *annotation)
> +{
> +	struct timespec ts;
> +	struct rtc_time tm;
> +
> +	getnstimeofday(&ts);
> +	rtc_time_to_tm(ts.tv_sec, &tm);
> +	pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
> +		annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
> +		tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
> +}
> +
>  /**
>   * pm_suspend - Externally visible function for suspending the system.
>   * @state: System sleep state to enter.
> @@ -577,6 +590,7 @@ int pm_suspend(suspend_state_t state)
>  	if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
>  		return -EINVAL;
>  
> +	pm_suspend_marker("entry");
>  	error = enter_state(state);
>  	if (error) {
>  		suspend_stats.fail++;
> @@ -584,6 +598,7 @@ int pm_suspend(suspend_state_t state)
>  	} else {
>  		suspend_stats.success++;
>  	}
> +	pm_suspend_marker("exit");
>  	return error;
>  }
>  EXPORT_SYMBOL(pm_suspend);

-- 
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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