[PATCH 10 update] PM: Measure suspend and resume times for individual devices
From: Rafael J. Wysocki
Date: Mon Aug 31 2009 - 17:31:44 EST
On Monday 31 August 2009, Rafael J. Wysocki wrote:
> On Monday 31 August 2009, Ingo Molnar wrote:
...
> > > > Hm, these CPP macros are rather ugly. Why is there a need for
> > > > the TIMER_DECLARE() wrapper - if a proper inline function is
> > > > used there's no need for that.
> > >
> > > I need a variable to be declared so that I can save the "start"
> > > timestamp in it. I don't need the variable if DEBUG is unset,
> > > though.
> > >
> > > How would you do that without using a macro? Or #ifdef #endif
> > > block that would be uglier IMO (which is why I didn't do that)?
> >
> > Well, why not use an inline function like i suggested? [which does
> > nothing in the !enabled case] You can keep the local variable always
> > defined.
>
> Well, I used the macros _exactly_ because I didn't want to keep the local
> variable always defined.
>
> Now, if you think that adding several useless bytes to the stack frame is OK,
> perhaps it can be always defined. However, IMnsHO that would be
> (a) confusing (why define a variable you don't use) and (b) wasteful.
>
> Perhaps the names of the macros should be directly related to debugging?
Something like in the patch below, maybe?
Best,
Rafael
---
From: Rafael J. Wysocki <rjw@xxxxxxx>
Subject: PM: Measure suspend and resume times for individual devices
If verbose PM debugging is enabled, measure and print the time of
suspending and resuming of individual devices.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/base/power/main.c | 51 +++++++++++++++++++++++++++++++++++++++++-----
kernel/power/swsusp.c | 2 -
2 files changed, 47 insertions(+), 6 deletions(-)
Index: linux-2.6/drivers/base/power/main.c
===================================================================
--- linux-2.6.orig/drivers/base/power/main.c
+++ linux-2.6/drivers/base/power/main.c
@@ -442,11 +442,11 @@ static bool pm_op_started(struct device
*/
int pm_time_elapsed(struct timeval *start, struct timeval *stop)
{
- s64 elapsed_centisecs64;
+ s64 elapsed_msecs64;
- elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
- do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
- return elapsed_centisecs64;
+ elapsed_msecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
+ do_div(elapsed_msecs64, NSEC_PER_SEC / 1000);
+ return elapsed_msecs64;
}
static char *pm_verb(int event)
@@ -476,7 +476,7 @@ static char *pm_verb(int event)
static void dpm_show_time(struct timeval *start, struct timeval *stop,
pm_message_t state, const char *info)
{
- int centisecs = pm_time_elapsed(start, stop);
+ int centisecs = pm_time_elapsed(start, stop) / 10;
printk(KERN_INFO "PM: %s%s%s of devices complete in %d.%02d seconds\n",
info ? info : "", info ? " " : "", pm_verb(state.event),
@@ -497,6 +497,33 @@ static void pm_dev_err(struct device *de
kobject_name(&dev->kobj), pm_verb(state.event), info, error);
}
+#ifdef DEBUG
+static void device_show_time(struct timeval *start, struct device *dev,
+ pm_message_t state, char *info)
+{
+ struct timeval stop;
+ int msecs;
+
+ do_gettimeofday(&stop);
+ msecs = pm_time_elapsed(start, &stop);
+ dev_dbg(dev, "PID %d: %s%s%s complete in %d.%03d seconds\n",
+ task_pid_nr(current), info ? info : "", info ? " " : "",
+ pm_verb(state.event), msecs / 1000, msecs % 1000);
+}
+
+#define DEBUG_TIMEVAL(tv) struct timeval tv
+#define DEBUG_TIME_START(tv) do { \
+ do_gettimeofday(&tv); \
+ } while (0)
+#define DEBUG_TIME_SHOW(tv, dev, state, info) do { \
+ device_show_time(&tv, dev, state, info); \
+ } while (0)
+#else /* !DEBUG */
+#define DEBUG_TIMEVAL(tv)
+#define DEBUG_TIME_START(tv) do { } while (0)
+#define DEBUG_TIME_SHOW(tv, dev, state, info) do { } while (0)
+#endif /* !DEBUG */
+
/*------------------------- Resume routines -------------------------*/
/**
@@ -510,7 +537,9 @@ static void pm_dev_err(struct device *de
static int __device_resume_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
+ DEBUG_TIMEVAL(start);
+ DEBUG_TIME_START(start);
TRACE_DEVICE(dev);
TRACE_RESUME(0);
@@ -523,6 +552,7 @@ static int __device_resume_noirq(struct
wake_up_all(&dev->power.wait_queue);
TRACE_RESUME(error);
+ DEBUG_TIME_SHOW(start, dev, state, "EARLY");
return error;
}
@@ -639,7 +669,9 @@ EXPORT_SYMBOL_GPL(dpm_resume_noirq);
static int __device_resume(struct device *dev, pm_message_t state)
{
int error = 0;
+ DEBUG_TIMEVAL(start);
+ DEBUG_TIME_START(start);
TRACE_DEVICE(dev);
TRACE_RESUME(0);
@@ -681,6 +713,7 @@ static int __device_resume(struct device
wake_up_all(&dev->power.wait_queue);
TRACE_RESUME(error);
+ DEBUG_TIME_SHOW(start, dev, state, NULL);
return error;
}
@@ -923,6 +956,9 @@ static pm_message_t resume_event(pm_mess
static int __device_suspend_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
+ DEBUG_TIMEVAL(start);
+
+ DEBUG_TIME_START(start);
if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "LATE ");
@@ -932,6 +968,7 @@ static int __device_suspend_noirq(struct
dev->power.op_complete = true;
wake_up_all(&dev->power.wait_queue);
+ DEBUG_TIME_SHOW(start, dev, state, "LATE");
return error;
}
@@ -1063,6 +1100,9 @@ EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
static int __device_suspend(struct device *dev, pm_message_t state)
{
int error = 0;
+ DEBUG_TIMEVAL(start);
+
+ DEBUG_TIME_START(start);
down(&dev->sem);
@@ -1103,6 +1143,7 @@ static int __device_suspend(struct devic
dev->power.op_complete = true;
wake_up_all(&dev->power.wait_queue);
+ DEBUG_TIME_SHOW(start, dev, state, NULL);
return error;
}
Index: linux-2.6/kernel/power/swsusp.c
===================================================================
--- linux-2.6.orig/kernel/power/swsusp.c
+++ linux-2.6/kernel/power/swsusp.c
@@ -169,7 +169,7 @@ int swsusp_swap_in_use(void)
void swsusp_show_speed(struct timeval *start, struct timeval *stop,
unsigned nr_pages, char *msg)
{
- int centisecs = pm_time_elapsed(start, stop);
+ int centisecs = pm_time_elapsed(start, stop) / 10;
int k;
int kps;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/