[PATCH] Add debugging feature /proc/timer_stat

[deliverable/linux.git] / kernel / hrtimer.c

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 62aad8e1a3835c9e390ff93e383dbceff3755d4d..476cb0c0b4a432bce65c1f113011aa60cd3060b0 100644 (file)
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -585,6 +585,18 @@ static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
 
 #endif /* CONFIG_HIGH_RES_TIMERS */
 
+#ifdef CONFIG_TIMER_STATS
+void __timer_stats_hrtimer_set_start_info(struct hrtimer *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
+
 /*
  * Counterpart to lock_timer_base above:
  */
@@ -743,6 +755,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
                 * reprogramming happens in the interrupt handler. This is a
                 * rare case and less expensive than a smp call.
                 */
+               timer_stats_hrtimer_clear_start_info(timer);
                reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
                __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
                                 reprogram);
@@ -791,6 +804,8 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
        }
        timer->expires = tim;
 
+       timer_stats_hrtimer_set_start_info(timer);
+
        enqueue_hrtimer(timer, new_base, base == new_base);
 
        unlock_hrtimer_base(timer, &flags);
@@ -925,6 +940,12 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 
        timer->base = &cpu_base->clock_base[clock_id];
        hrtimer_init_timer_hres(timer);
+
+#ifdef CONFIG_TIMER_STATS
+       timer->start_site = NULL;
+       timer->start_pid = -1;
+       memset(timer->start_comm, 0, TASK_COMM_LEN);
+#endif
 }
 EXPORT_SYMBOL_GPL(hrtimer_init);
 
@@ -1006,6 +1027,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 
                        __remove_hrtimer(timer, base,
                                         HRTIMER_STATE_CALLBACK, 0);
+                       timer_stats_account_hrtimer(timer);
 
                        /*
                         * Note: We clear the CALLBACK bit after
@@ -1050,6 +1072,8 @@ static void run_hrtimer_softirq(struct softirq_action *h)
                timer = list_entry(cpu_base->cb_pending.next,
                                   struct hrtimer, cb_entry);
 
+               timer_stats_account_hrtimer(timer);
+
                fn = timer->function;
                __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
                spin_unlock_irq(&cpu_base->lock);
@@ -1106,6 +1130,8 @@ static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
                if (base->softirq_time.tv64 <= timer->expires.tv64)
                        break;
 
+               timer_stats_account_hrtimer(timer);
+
                fn = timer->function;
                __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
                spin_unlock_irq(&cpu_base->lock);