PM / sleep: trace events for suspend/resume

Adds trace events that give finer resolution into suspend/resume. These
events are graphed in the timelines generated by the analyze_suspend.py
script. They represent large areas of time consumed that are typical to
suspend and resume.

The event is triggered by calling the function "trace_suspend_resume"
with three arguments: a string (the name of the event to be displayed
in the timeline), an integer (case specific number, such as the power
state or cpu number), and a boolean (where true is used to denote the start
of the timeline event, and false to denote the end).

The suspend_resume trace event reproduces the data that the machine_suspend
trace event did, so the latter has been removed.

Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/cpu.c

@@ -20,6 +20,7 @@
 #include <linux/gfp.h>
 #include <linux/suspend.h>
 #include <linux/lockdep.h>
+#include <trace/events/power.h>
 
 #include "smpboot.h"
 
@@ -522,7 +523,9 @@ int disable_nonboot_cpus(void)
 	for_each_online_cpu(cpu) {
 		if (cpu == first_cpu)
 			continue;
+		trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
 		error = _cpu_down(cpu, 1);
+		trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
 		if (!error)
 			cpumask_set_cpu(cpu, frozen_cpus);
 		else {
@@ -566,7 +569,9 @@ void __ref enable_nonboot_cpus(void)
 	arch_enable_nonboot_cpus_begin();
 
 	for_each_cpu(cpu, frozen_cpus) {
+		trace_suspend_resume(TPS("CPU_ON"), cpu, true);
 		error = _cpu_up(cpu, 1);
+		trace_suspend_resume(TPS("CPU_ON"), cpu, false);
 		if (!error) {
 			printk(KERN_INFO "CPU%d is up\n", cpu);
 			continue;

kernel/power/hibernate.c

@@ -28,6 +28,7 @@
 #include <linux/syscore_ops.h>
 #include <linux/ctype.h>
 #include <linux/genhd.h>
+#include <trace/events/power.h>
 
 #include "power.h"
 
@@ -292,7 +293,9 @@ static int create_image(int platform_mode)
 
 	in_suspend = 1;
 	save_processor_state();
+	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 	error = swsusp_arch_suspend();
+	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 	if (error)
 		printk(KERN_ERR "PM: Error %d creating hibernation image\n",
 			error);

kernel/power/process.c

@@ -17,6 +17,7 @@
 #include <linux/delay.h>
 #include <linux/workqueue.h>
 #include <linux/kmod.h>
+#include <trace/events/power.h>
 
 /* 
  * Timeout for stopping processes
@@ -175,6 +176,7 @@ void thaw_processes(void)
 	struct task_struct *g, *p;
 	struct task_struct *curr = current;
 
+	trace_suspend_resume(TPS("thaw_processes"), 0, true);
 	if (pm_freezing)
 		atomic_dec(&system_freezing_cnt);
 	pm_freezing = false;
@@ -201,6 +203,7 @@ void thaw_processes(void)
 
 	schedule();
 	printk("done.\n");
+	trace_suspend_resume(TPS("thaw_processes"), 0, false);
 }
 
 void thaw_kernel_threads(void)

kernel/power/suspend.c

@@ -177,7 +177,9 @@ static int suspend_prepare(suspend_state_t state)
 	if (error)
 		goto Finish;
 
+	trace_suspend_resume(TPS("freeze_processes"), 0, true);
 	error = suspend_freeze_processes();
+	trace_suspend_resume(TPS("freeze_processes"), 0, false);
 	if (!error)
 		return 0;
 
@@ -240,7 +242,9 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	 * all the devices are suspended.
 	 */
 	if (state == PM_SUSPEND_FREEZE) {
+		trace_suspend_resume(TPS("machine_suspend"), state, true);
 		freeze_enter();
+		trace_suspend_resume(TPS("machine_suspend"), state, false);
 		goto Platform_wake;
 	}
 
@@ -256,7 +260,11 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	if (!error) {
 		*wakeup = pm_wakeup_pending();
 		if (!(suspend_test(TEST_CORE) || *wakeup)) {
+			trace_suspend_resume(TPS("machine_suspend"),
+				state, true);
 			error = suspend_ops->enter(state);
+			trace_suspend_resume(TPS("machine_suspend"),
+				state, false);
 			events_check_enabled = false;
 		}
 		syscore_resume();
@@ -294,7 +302,6 @@ int suspend_devices_and_enter(suspend_state_t state)
 	if (need_suspend_ops(state) && !suspend_ops)
 		return -ENOSYS;
 
-	trace_machine_suspend(state);
 	if (need_suspend_ops(state) && suspend_ops->begin) {
 		error = suspend_ops->begin(state);
 		if (error)
@@ -331,7 +338,6 @@ int suspend_devices_and_enter(suspend_state_t state)
 	else if (state == PM_SUSPEND_FREEZE && freeze_ops->end)
 		freeze_ops->end();
 
-	trace_machine_suspend(PWR_EVENT_EXIT);
 	return error;
 
  Recover_platform:
@@ -365,6 +371,7 @@ static int enter_state(suspend_state_t state)
 {
 	int error;
 
+	trace_suspend_resume(TPS("suspend_enter"), state, true);
 	if (state == PM_SUSPEND_FREEZE) {
 #ifdef CONFIG_PM_DEBUG
 		if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
@@ -382,9 +389,11 @@ static int enter_state(suspend_state_t state)
 	if (state == PM_SUSPEND_FREEZE)
 		freeze_begin();
 
+	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
 	printk(KERN_INFO "PM: Syncing filesystems ... ");
 	sys_sync();
 	printk("done.\n");
+	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
 
 	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state].label);
 	error = suspend_prepare(state);
@@ -394,6 +403,7 @@ static int enter_state(suspend_state_t state)
 	if (suspend_test(TEST_FREEZER))
 		goto Finish;
 
+	trace_suspend_resume(TPS("suspend_enter"), state, false);
 	pr_debug("PM: Entering %s sleep\n", pm_states[state].label);
 	pm_restrict_gfp_mask();
 	error = suspend_devices_and_enter(state);