GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-21 14:11:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

[PATCH] Add debugging feature /proc/timer_stat

Browse source 
Add /proc/timer_stats support: debugging feature to profile timer expiration.
Both the starting site, process/PID and the expiration function is captured.
This allows the quick identification of timer event sources in a system.

Sample output:

# echo 1 > /proc/timer_stats
# cat /proc/timer_stats
Timer Stats Version: v0.1
Sample period: 4.010 s
  24,     0 swapper          hrtimer_stop_sched_tick (hrtimer_sched_tick)
  11,     0 swapper          sk_reset_timer (tcp_delack_timer)
   6,     0 swapper          hrtimer_stop_sched_tick (hrtimer_sched_tick)
   2,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
  17,     0 swapper          hrtimer_restart_sched_tick (hrtimer_sched_tick)
   2,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
   4,  2050 pcscd            do_nanosleep (hrtimer_wakeup)
   5,  4179 sshd             sk_reset_timer (tcp_write_timer)
   4,  2248 yum-updatesd     schedule_timeout (process_timeout)
  18,     0 swapper          hrtimer_restart_sched_tick (hrtimer_sched_tick)
   3,     0 swapper          sk_reset_timer (tcp_delack_timer)
   1,     1 swapper          neigh_table_init_no_netlink (neigh_periodic_timer)
   2,     1 swapper          e1000_up (e1000_watchdog)
   1,     1 init             schedule_timeout (process_timeout)
100 total events, 25.24 events/sec

[ cleanups and hrtimers support from Thomas Gleixner <tglx@linutronix.de> ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ingo Molnar 2007-02-16 01:28:13 -08:00 • committed by Linus Torvalds
parent 8bfd9a7a22
commit 82f67cd9fc
9 changed files with 650 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

31
kernel/timer.c
View file

@ -35,6 +35,7 @@
#include <linux/syscalls.h>
#include <linux/delay.h>
#include <linux/tick.h>
#include <linux/kallsyms.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@ -263,6 +264,18 @@ static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
list_add_tail(&timer->entry, vec);
}
#ifdef CONFIG_TIMER_STATS
void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
{
if (timer->start_site)
return;
timer->start_site = addr;
memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
timer->start_pid = current->pid;
}
#endif
/**
* init_timer - initialize a timer.
* @timer: the timer to be initialized
@ -274,11 +287,16 @@ void fastcall init_timer(struct timer_list *timer)
{
timer->entry.next = NULL;
timer->base = __raw_get_cpu_var(tvec_bases);
#ifdef CONFIG_TIMER_STATS
timer->start_site = NULL;
timer->start_pid = -1;
memset(timer->start_comm, 0, TASK_COMM_LEN);
#endif
}
EXPORT_SYMBOL(init_timer);
static inline void detach_timer(struct timer_list *timer,
int clear_pending)
int clear_pending)
{
struct list_head *entry = &timer->entry;
@ -325,6 +343,7 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
unsigned long flags;
int ret = 0;
timer_stats_timer_set_start_info(timer);
BUG_ON(!timer->function);
base = lock_timer_base(timer, &flags);
@ -375,6 +394,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
tvec_base_t *base = per_cpu(tvec_bases, cpu);
unsigned long flags;
timer_stats_timer_set_start_info(timer);
BUG_ON(timer_pending(timer) || !timer->function);
spin_lock_irqsave(&base->lock, flags);
timer->base = base;
@ -407,6 +427,7 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
{
BUG_ON(!timer->function);
timer_stats_timer_set_start_info(timer);
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
@ -437,6 +458,7 @@ int del_timer(struct timer_list *timer)
unsigned long flags;
int ret = 0;
timer_stats_timer_clear_start_info(timer);
if (timer_pending(timer)) {
base = lock_timer_base(timer, &flags);
if (timer_pending(timer)) {
@ -570,6 +592,8 @@ static inline void __run_timers(tvec_base_t *base)
fn = timer->function;
data = timer->data;
timer_stats_account_timer(timer);
set_running_timer(base, timer);
detach_timer(timer, 1);
spin_unlock_irq(&base->lock);
@ -1229,7 +1253,8 @@ static void run_timer_softirq(struct softirq_action *h)
{
tvec_base_t *base = __get_cpu_var(tvec_bases);
hrtimer_run_queues();
hrtimer_run_queues();
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
}
@ -1675,6 +1700,8 @@ void __init init_timers(void)
int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
init_timer_stats();
BUG_ON(err == NOTIFY_BAD);
register_cpu_notifier(&timers_nb);
open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);