Re: [PATCH] suspend: add initcall_debug style timing for suspend/resume

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Sunday 06 December 2009, Arjan van de Ven wrote:
> 
> From fcd52b97aa02f19baa570e4a62dfdfab0faed976 Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <arjan@linux.intel.com>
> Date: Sun, 6 Dec 2009 12:32:28 -0800
> Subject: [PATCH] suspend: add initcall_debug style timing for suspend/resume
> 
> In order to diagnose overall suspend/resume times, we need
> basic instrumentation to break down the total time into per
> device timing, similar to initcall_debug.
> 
> This patch adds the basic timing instrumentation, needed
> for a scritps/bootgraph.pl equivalent or humans.
> The bootgraph.pl program is still a work in progress, but
> is far enough along to know that this patch is sufficient.
> 
> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
> ---
>  drivers/base/power/main.c |   29 +++++++++++++++++++++++++++++
>  include/linux/init.h      |    2 ++
>  2 files changed, 31 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index 8aa2443..2ad345c 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -25,6 +25,7 @@
>  #include <linux/resume-trace.h>
>  #include <linux/rwsem.h>
>  #include <linux/interrupt.h>
> +#include <linux/sched.h>
>  
>  #include "../base.h"
>  #include "power.h"
> @@ -172,6 +173,12 @@ static int pm_op(struct device *dev,
>  		 pm_message_t state)
>  {
>  	int error = 0;
> +	ktime_t calltime, delta, rettime;
> +
> +	if (initcall_debug) {
> +		printk("calling  %s+ @ %i\n", dev_name(dev), task_pid_nr(current));
> +		calltime = ktime_get();
> +	}
>  
>  	switch (state.event) {
>  #ifdef CONFIG_SUSPEND
> @@ -219,6 +226,14 @@ static int pm_op(struct device *dev,
>  	default:
>  		error = -EINVAL;
>  	}
> +
> +	if (initcall_debug) {
> +		rettime = ktime_get();
> +		delta = ktime_sub(rettime, calltime);
> +		printk("initcall %s+ returned %d after %Ld usecs\n", dev_name(dev),
> +			error, (unsigned long long) ktime_to_ns(delta) >> 10);

I've changed that "initcall" to "call".  Hopefully that won't break your scripts. ;-)

Rafael