mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-16 17:23:55 +08:00
bc078e4eab
Oprofile is currently broken on systems running with NOHZ enabled. A maximum of 1 tick is accounted via the timer_hook if a cpu sleeps for a longer period of time. This does bad things to the percentages in the profiler output. To solve this problem convert oprofile to use a restarting hrtimer instead of the timer_hook. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
107 lines
2.2 KiB
C
107 lines
2.2 KiB
C
/**
|
|
* @file timer_int.c
|
|
*
|
|
* @remark Copyright 2002 OProfile authors
|
|
* @remark Read the file COPYING
|
|
*
|
|
* @author John Levon <levon@movementarian.org>
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/oprofile.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/init.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/hrtimer.h>
|
|
#include <asm/irq_regs.h>
|
|
#include <asm/ptrace.h>
|
|
|
|
#include "oprof.h"
|
|
|
|
static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
|
|
|
|
static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
|
|
{
|
|
oprofile_add_sample(get_irq_regs(), 0);
|
|
hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
|
|
return HRTIMER_RESTART;
|
|
}
|
|
|
|
static void __oprofile_hrtimer_start(void *unused)
|
|
{
|
|
struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
|
|
|
|
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
hrtimer->function = oprofile_hrtimer_notify;
|
|
|
|
hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
|
|
HRTIMER_MODE_REL_PINNED);
|
|
}
|
|
|
|
static int oprofile_hrtimer_start(void)
|
|
{
|
|
on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
|
|
return 0;
|
|
}
|
|
|
|
static void __oprofile_hrtimer_stop(int cpu)
|
|
{
|
|
struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
|
|
|
|
hrtimer_cancel(hrtimer);
|
|
}
|
|
|
|
static void oprofile_hrtimer_stop(void)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_online_cpu(cpu)
|
|
__oprofile_hrtimer_stop(cpu);
|
|
}
|
|
|
|
static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
long cpu = (long) hcpu;
|
|
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
case CPU_ONLINE_FROZEN:
|
|
smp_call_function_single(cpu, __oprofile_hrtimer_start,
|
|
NULL, 1);
|
|
break;
|
|
case CPU_DEAD:
|
|
case CPU_DEAD_FROZEN:
|
|
__oprofile_hrtimer_stop(cpu);
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block __refdata oprofile_cpu_notifier = {
|
|
.notifier_call = oprofile_cpu_notify,
|
|
};
|
|
|
|
int __init oprofile_timer_init(struct oprofile_operations *ops)
|
|
{
|
|
int rc;
|
|
|
|
rc = register_hotcpu_notifier(&oprofile_cpu_notifier);
|
|
if (rc)
|
|
return rc;
|
|
ops->create_files = NULL;
|
|
ops->setup = NULL;
|
|
ops->shutdown = NULL;
|
|
ops->start = oprofile_hrtimer_start;
|
|
ops->stop = oprofile_hrtimer_stop;
|
|
ops->cpu_type = "timer";
|
|
return 0;
|
|
}
|
|
|
|
void __exit oprofile_timer_exit(void)
|
|
{
|
|
unregister_hotcpu_notifier(&oprofile_cpu_notifier);
|
|
}
|