Commit 0075fa80 authored by Ingo Molnar's avatar Ingo Molnar Committed by Thomas Gleixner
Browse files

ftrace: extend sysprof plugin 



add per CPU hrtimers.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent f06c3810

kernel/trace/trace_sysprof.c

+63 −4
Original line number Diff line number Diff line
@@ -5,19 +5,76 @@ 
 * 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;
@@ -31,11 +88,13 @@ static notrace void stack_reset(struct trace_array *tr) 
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;

}