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PM / tick: Add tracepoints for suspend-to-idle diagnostics

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Add suspend/resume tracepoints to tick_freeze() and tick_unfreeze()
to catch when timekeeping is suspended and resumed during suspend-to-idle
so as to be able to check whether or not we enter the "frozen" state
and to measure the time spent in it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Rafael J. Wysocki 2015-05-10 01:23:35 +02:00
parent 819b1bb30d
commit 75e0678e70
1 changed files with 11 additions and 4 deletions
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15
kernel/time/tick-common.c
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@ -19,6 +19,7 @@
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <trace/events/power.h>
#include <asm/irq_regs.h>
@ -457,10 +458,13 @@ void tick_freeze(void)
raw_spin_lock(&tick_freeze_lock);
tick_freeze_depth++;
if (tick_freeze_depth == num_online_cpus())
if (tick_freeze_depth == num_online_cpus()) {
trace_suspend_resume(TPS("timekeeping_freeze"),
smp_processor_id(), true);
timekeeping_suspend();
else
} else {
tick_suspend_local();
}
raw_spin_unlock(&tick_freeze_lock);
}
@ -478,10 +482,13 @@ void tick_unfreeze(void)
{
raw_spin_lock(&tick_freeze_lock);
if (tick_freeze_depth == num_online_cpus())
if (tick_freeze_depth == num_online_cpus()) {
timekeeping_resume();
else
trace_suspend_resume(TPS("timekeeping_freeze"),
smp_processor_id(), false);
} else {
tick_resume_local();
}
tick_freeze_depth--;