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Commit 61613521 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Ingo Molnar
Browse files

tracing, perf: Convert the power tracer into an event tracer 



This patch converts the existing power tracer into an event tracer,
so that power events (C states and frequency changes) can be
tracked via "perf".

This also removes the perl script that was used to demo the tracer;
its functionality is being replaced entirely with timechart.

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130542.6d314860@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent fd39e055

Documentation/trace/power.txt

deleted100644 → 0
+0 −17
Original line number Diff line number Diff line 
The power tracer collects detailed information about C-state and P-state

transitions, instead of just looking at the high-level "average"

information.



There is a helper script found in scrips/tracing/power.pl in the kernel

sources which can be used to parse this information and create a

Scalable Vector Graphics (SVG) picture from the trace data.



To use this tracer:



	echo 0 > /sys/kernel/debug/tracing/tracing_enabled

	echo power > /sys/kernel/debug/tracing/current_tracer

	echo 1 > /sys/kernel/debug/tracing/tracing_enabled

	sleep 1

	echo 0 > /sys/kernel/debug/tracing/tracing_enabled

	cat /sys/kernel/debug/tracing/trace | \

		perl scripts/tracing/power.pl > out.sv

arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c

+2 −5
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ 
#include <linux/cpufreq.h>

#include <linux/compiler.h>

#include <linux/dmi.h>

#include <trace/power.h>

#include <trace/events/power.h>



#include <linux/acpi.h>

#include <linux/io.h>
@@ -72,8 +72,6 @@ static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data); 


static DEFINE_PER_CPU(struct aperfmperf, old_perf);



DEFINE_TRACE(power_mark);



/* acpi_perf_data is a pointer to percpu data. */

static struct acpi_processor_performance *acpi_perf_data;
@@ -332,7 +330,6 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, 
	unsigned int next_perf_state = 0; /* Index into perf table */

	unsigned int i;

	int result = 0;

	struct power_trace it;



	dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
@@ -364,7 +361,7 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, 
		}

	}



	trace_power_mark(&it, POWER_PSTATE, next_perf_state);

	trace_power_frequency(POWER_PSTATE, data->freq_table[next_state].frequency);



	switch (data->cpu_feature) {

	case SYSTEM_INTEL_MSR_CAPABLE:

arch/x86/kernel/process.c

+9 −19
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 
#include <linux/pm.h>

#include <linux/clockchips.h>

#include <linux/random.h>

#include <trace/power.h>

#include <trace/events/power.h>

#include <asm/system.h>

#include <asm/apic.h>

#include <asm/syscalls.h>
@@ -25,9 +25,6 @@ EXPORT_SYMBOL(idle_nomwait); 


struct kmem_cache *task_xstate_cachep;



DEFINE_TRACE(power_start);

DEFINE_TRACE(power_end);



int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)

{

	*dst = *src;
@@ -299,9 +296,7 @@ static inline int hlt_use_halt(void) 
void default_idle(void)

{

	if (hlt_use_halt()) {

		struct power_trace it;



		trace_power_start(&it, POWER_CSTATE, 1);

		trace_power_start(POWER_CSTATE, 1);

		current_thread_info()->status &= ~TS_POLLING;

		/*

		 * TS_POLLING-cleared state must be visible before we
@@ -314,7 +309,7 @@ void default_idle(void) 
		else

			local_irq_enable();

		current_thread_info()->status |= TS_POLLING;

		trace_power_end(&it);

		trace_power_end(0);

	} else {

		local_irq_enable();

		/* loop is done by the caller */
@@ -372,9 +367,7 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait); 
 */

void mwait_idle_with_hints(unsigned long ax, unsigned long cx)

{

	struct power_trace it;



	trace_power_start(&it, POWER_CSTATE, (ax>>4)+1);

	trace_power_start(POWER_CSTATE, (ax>>4)+1);

	if (!need_resched()) {

		if (cpu_has(&current_cpu_data, X86_FEATURE_CLFLUSH_MONITOR))

			clflush((void *)&current_thread_info()->flags);
@@ -384,15 +377,14 @@ void mwait_idle_with_hints(unsigned long ax, unsigned long cx) 
		if (!need_resched())

			__mwait(ax, cx);

	}

	trace_power_end(&it);

	trace_power_end(0);

}



/* Default MONITOR/MWAIT with no hints, used for default C1 state */

static void mwait_idle(void)

{

	struct power_trace it;

	if (!need_resched()) {

		trace_power_start(&it, POWER_CSTATE, 1);

		trace_power_start(POWER_CSTATE, 1);

		if (cpu_has(&current_cpu_data, X86_FEATURE_CLFLUSH_MONITOR))

			clflush((void *)&current_thread_info()->flags);
@@ -402,7 +394,7 @@ static void mwait_idle(void) 
			__sti_mwait(0, 0);

		else

			local_irq_enable();

		trace_power_end(&it);

		trace_power_end(0);

	} else

		local_irq_enable();

}
@@ -414,13 +406,11 @@ static void mwait_idle(void) 
 */

static void poll_idle(void)

{

	struct power_trace it;



	trace_power_start(&it, POWER_CSTATE, 0);

	trace_power_start(POWER_CSTATE, 0);

	local_irq_enable();

	while (!need_resched())

		cpu_relax();

	trace_power_end(&it);

	trace_power_end(0);

}



/*

include/trace/events/power.h

0 → 100644
+81 −0
Original line number Diff line number Diff line 
#undef TRACE_SYSTEM

#define TRACE_SYSTEM power



#if !defined(_TRACE_POWER_H) || defined(TRACE_HEADER_MULTI_READ)

#define _TRACE_POWER_H



#include <linux/ktime.h>

#include <linux/tracepoint.h>



#ifndef _TRACE_POWER_ENUM_

#define _TRACE_POWER_ENUM_

enum {

	POWER_NONE = 0,

	POWER_CSTATE = 1,

	POWER_PSTATE = 2,

};

#endif







TRACE_EVENT(power_start,



	TP_PROTO(unsigned int type, unsigned int state),



	TP_ARGS(type, state),



	TP_STRUCT__entry(

		__field(	u64,		type		)

		__field(	u64,		state		)

	),



	TP_fast_assign(

		__entry->type = type;

		__entry->state = state;

	),



	TP_printk("type=%lu state=%lu", (unsigned long)__entry->type, (unsigned long)__entry->state)

);



TRACE_EVENT(power_end,



	TP_PROTO(int dummy),



	TP_ARGS(dummy),



	TP_STRUCT__entry(

		__field(	u64,		dummy		)

	),



	TP_fast_assign(

		__entry->dummy = 0xffff;

	),



	TP_printk("dummy=%lu", (unsigned long)__entry->dummy)



);





TRACE_EVENT(power_frequency,



	TP_PROTO(unsigned int type, unsigned int state),



	TP_ARGS(type, state),



	TP_STRUCT__entry(

		__field(	u64,		type		)

		__field(	u64,		state		)

	),



	TP_fast_assign(

		__entry->type = type;

		__entry->state = state;

	),



	TP_printk("type=%lu state=%lu", (unsigned long)__entry->type, (unsigned long) __entry->state)

);



#endif /* _TRACE_POWER_H */



/* This part must be outside protection */

#include <trace/define_trace.h>

kernel/trace/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -42,7 +42,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o 
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o

obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o

obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o

obj-$(CONFIG_POWER_TRACER) += trace_power.o

obj-$(CONFIG_KMEMTRACE) += kmemtrace.o

obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o

obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
@@ -54,5 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o 
obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o

obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o

obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o

obj-$(CONFIG_EVENT_TRACING) += power-traces.o



libftrace-y := ftrace.o