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ftrace: extend sysprof plugin

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add per CPU hrtimers.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar 2008-05-12 21:20:47 +02:00 committed by Thomas Gleixner
parent f06c38103e
commit 0075fa8030
1 changed files with 64 additions and 5 deletions
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69
kernel/trace/trace_sysprof.c
View file

@ -5,19 +5,76 @@
* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
*
*/
#include <linux/kallsyms.h>
#include <linux/debugfs.h>
#include <linux/hrtimer.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/marker.h>
#include <linux/ftrace.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;
}