[PATCH 3/3] trace points: power: remove 'cpu_id' from trace_cpu_idle

tom.leiming
2011-08-19T15:04:53Z

From: Ming Lei <tom.leiming@gmail.com>

This patch removes the 'cpu_id' parameter of the cpu_idle
trace point, based on the ideas below:

- the cpu_id which is passed to trace point is always the current
cpu
- the current cpu info has been included into the trace result
already
- smp_processor_id() can't be used safely in preemptible context.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
Documentation/trace/events-power.txt | 6 +++---
arch/arm/mach-omap2/pm34xx.c | 4 ++--
arch/x86/kernel/process.c | 12 ++++++------
drivers/cpuidle/cpuidle.c | 4 ++--
include/trace/events/power.h | 15 ++++++++++++---
5 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/Documentation/trace/events-power.txt b/Documentation/trace/events-power.txt
index e9d5fe3..9f2f96c 100644
--- a/Documentation/trace/events-power.txt
+++ b/Documentation/trace/events-power.txt
@@ -23,7 +23,7 @@ Cf. include/trace/events/power.h for the events definitions.
A 'cpu' event class gathers the CPU-related events: cpuidle and
cpufreq.

-cpu_idle "state=%lu cpu_id=%lu"
+cpu_idle "state=%lu"
cpu_frequency "state=%lu cpu_id=%lu"

A suspend event is used to indicate the system going in and out of the
@@ -33,8 +33,8 @@ machine_suspend "state=%lu"

Note: the value of '-1' or '4294967295' for state means an exit from the current state,
-i.e. trace_cpu_idle(4, smp_processor_id()) means that the system
-enters the idle state 4, while trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id())
+i.e. trace_cpu_idle(4) means that the system
+enters the idle state 4, while trace_cpu_idle(PWR_EVENT_EXIT)
means that the system exits the previous idle state.

The event which has 'state=4294967295' in the trace is very important to the user
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 7255d9b..cde9a11 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -502,12 +502,12 @@ static void omap3_pm_idle(void)
goto out;

trace_power_start(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle(1, smp_processor_id());
+ trace_cpu_idle(1);

omap_sram_idle();

trace_power_end(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_cpu_idle(PWR_EVENT_EXIT);

out:
local_fiq_enable();
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index e7e3b01..fb9e92b 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -378,7 +378,7 @@ void default_idle(void)
{
if (hlt_use_halt()) {
trace_power_start(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle(1, smp_processor_id());
+ trace_cpu_idle(1);
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
@@ -392,7 +392,7 @@ void default_idle(void)
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
trace_power_end(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_cpu_idle(PWR_EVENT_EXIT);
} else {
local_irq_enable();
/* loop is done by the caller */
@@ -443,7 +443,7 @@ static void mwait_idle(void)
{
if (!need_resched()) {
trace_power_start(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle(1, smp_processor_id());
+ trace_cpu_idle(1);
if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
clflush((void *)&current_thread_info()->flags);

@@ -454,7 +454,7 @@ static void mwait_idle(void)
else
local_irq_enable();
trace_power_end(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_cpu_idle(PWR_EVENT_EXIT);
} else
local_irq_enable();
}
@@ -467,12 +467,12 @@ static void mwait_idle(void)
static void poll_idle(void)
{
trace_power_start(POWER_CSTATE, 0, smp_processor_id());
- trace_cpu_idle(0, smp_processor_id());
+ trace_cpu_idle(0);
local_irq_enable();
while (!need_resched())
cpu_relax();
trace_power_end(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_cpu_idle(PWR_EVENT_EXIT);
}

/*
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index d4c5423..7980732 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -106,12 +106,12 @@ int cpuidle_idle_call(void)
dev->last_state = target_state;

trace_power_start(POWER_CSTATE, next_state, dev->cpu);
- trace_cpu_idle(next_state, dev->cpu);
+ trace_cpu_idle(next_state);

dev->last_residency = target_state->enter(dev, target_state);

trace_power_end(dev->cpu);
- trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
+ trace_cpu_idle(PWR_EVENT_EXIT);

if (dev->last_state)
target_state = dev->last_state;
diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index 3878edc..8a579bd 100644
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -27,11 +27,20 @@ DECLARE_EVENT_CLASS(cpu,
(unsigned long)__entry->cpu_id)
);

-DEFINE_EVENT(cpu, cpu_idle,
+TRACE_EVENT(cpu_idle,
+ TP_PROTO(unsigned int state),

- TP_PROTO(unsigned int state, unsigned int cpu_id),
+ TP_ARGS(state),
+
+ TP_STRUCT__entry(
+ __field( u32, state )
+ ),
+
+ TP_fast_assign(
+ __entry->state = state;
+ ),

- TP_ARGS(state, cpu_id)
+ TP_printk("state=%lu", (unsigned long)__entry->state)
);

/* This file can get included multiple times, TRACE_HEADER_MULTI_READ at top */
--
1.7.4.1