ftrace: extend sysprof plugin

 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>

 *

 */

#include <linux/module.h>

#include <linux/fs.h>

#include <linux/debugfs.h>

#include <linux/kallsyms.h>

#include <linux/debugfs.h>

#include <linux/hrtimer.h>

#include <linux/uaccess.h>

#include <linux/marker.h>

#include <linux/ftrace.h>

#include <linux/module.h>

#include <linux/fs.h>

#include "trace.h"

static struct trace_array	*ctx_trace;

static int __read_mostly	tracer_enabled;

static const unsigned long sample_period = 1000000;

/*

 * Per CPU hrtimers that do the profiling:

 */

static DEFINE_PER_CPU(struct hrtimer, stack_trace_hrtimer);

static enum hrtimer_restart stack_trace_timer_fn(struct hrtimer *hrtimer)

{

	/* trace here */

	panic_timeout++;

	hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period));

	return HRTIMER_RESTART;

}

static void start_stack_timer(int cpu)

{

	struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);

	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

	hrtimer->function = stack_trace_timer_fn;

	hrtimer->cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;

	hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL);

}

static void start_stack_timers(void)

{

	cpumask_t saved_mask = current->cpus_allowed;

	int cpu;

	for_each_online_cpu(cpu) {

		set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));

		start_stack_timer(cpu);

		printk("started timer on cpu%d\n", cpu);

	}

	set_cpus_allowed_ptr(current, &saved_mask);

}

static void stop_stack_timer(int cpu)

{

	struct hrtimer *hrtimer = &per_cpu(stack_trace_hrtimer, cpu);

	hrtimer_cancel(hrtimer);

	printk("cancelled timer on cpu%d\n", cpu);

}

static void stop_stack_timers(void)

{

	int cpu;

	for_each_online_cpu(cpu)

		stop_stack_timer(cpu);

}

static notrace void stack_reset(struct trace_array *tr)

{

	int cpu;

static notrace void start_stack_trace(struct trace_array *tr)

{

	stack_reset(tr);

	start_stack_timers();

	tracer_enabled = 1;

}

static notrace void stop_stack_trace(struct trace_array *tr)

{

	stop_stack_timers();

	tracer_enabled = 0;

}