Commit 26e09c6e authored by Don Zickus's avatar Don Zickus Committed by Frederic Weisbecker
Browse files

lockup_detector: Convert per_cpu to __get_cpu_var for readability 



Just a bunch of conversions as suggested by Frederic W.
__get_cpu_var() provides preemption disabled checks.

Plus it gives more readability as it makes it obvious
we are dealing locally now with these vars.

Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
LKML-Reference: <1274133966-18415-2-git-send-email-dzickus@redhat.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent cafcd80d

kernel/watchdog.c

+17 −18
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ static unsigned long get_sample_period(void) 
/* Commands for resetting the watchdog */

static void __touch_watchdog(void)

{

	int this_cpu = raw_smp_processor_id();

	int this_cpu = smp_processor_id();



	__get_cpu_var(watchdog_touch_ts) = get_timestamp(this_cpu);

}
@@ -157,21 +157,21 @@ void touch_softlockup_watchdog_sync(void) 


#ifdef CONFIG_HARDLOCKUP_DETECTOR

/* watchdog detector functions */

static int is_hardlockup(int cpu)

static int is_hardlockup(void)

{

	unsigned long hrint = per_cpu(hrtimer_interrupts, cpu);

	unsigned long hrint = __get_cpu_var(hrtimer_interrupts);



	if (per_cpu(hrtimer_interrupts_saved, cpu) == hrint)

	if (__get_cpu_var(hrtimer_interrupts_saved) == hrint)

		return 1;



	per_cpu(hrtimer_interrupts_saved, cpu) = hrint;

	__get_cpu_var(hrtimer_interrupts_saved) = hrint;

	return 0;

}

#endif



static int is_softlockup(unsigned long touch_ts, int cpu)

static int is_softlockup(unsigned long touch_ts)

{

	unsigned long now = get_timestamp(cpu);

	unsigned long now = get_timestamp(smp_processor_id());



	/* Warn about unreasonable delays: */

	if (time_after(now, touch_ts + softlockup_thresh))
@@ -206,8 +206,6 @@ void watchdog_overflow_callback(struct perf_event *event, int nmi, 
		 struct perf_sample_data *data,

		 struct pt_regs *regs)

{

	int this_cpu = smp_processor_id();



	if (__get_cpu_var(watchdog_nmi_touch) == true) {

		__get_cpu_var(watchdog_nmi_touch) = false;

		return;
@@ -219,7 +217,9 @@ void watchdog_overflow_callback(struct perf_event *event, int nmi, 
	 * fired multiple times before we overflow'd.  If it hasn't

	 * then this is a good indication the cpu is stuck

	 */

	if (is_hardlockup(this_cpu)) {

	if (is_hardlockup()) {

		int this_cpu = smp_processor_id();



		/* only print hardlockups once */

		if (__get_cpu_var(hard_watchdog_warn) == true)

			return;
@@ -247,7 +247,6 @@ static inline void watchdog_interrupt_count(void) { return; } 
/* watchdog kicker functions */

static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)

{

	int this_cpu = smp_processor_id();

	unsigned long touch_ts = __get_cpu_var(watchdog_touch_ts);

	struct pt_regs *regs = get_irq_regs();

	int duration;
@@ -262,12 +261,12 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) 
	hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period()));



	if (touch_ts == 0) {

		if (unlikely(per_cpu(softlockup_touch_sync, this_cpu))) {

		if (unlikely(__get_cpu_var(softlockup_touch_sync))) {

			/*

			 * If the time stamp was touched atomically

			 * make sure the scheduler tick is up to date.

			 */

			per_cpu(softlockup_touch_sync, this_cpu) = false;

			__get_cpu_var(softlockup_touch_sync) = false;

			sched_clock_tick();

		}

		__touch_watchdog();
@@ -280,14 +279,14 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) 
	 * indicate it is getting cpu time.  If it hasn't then

	 * this is a good indication some task is hogging the cpu

	 */

	duration = is_softlockup(touch_ts, this_cpu);

	duration = is_softlockup(touch_ts);

	if (unlikely(duration)) {

		/* only warn once */

		if (__get_cpu_var(soft_watchdog_warn) == true)

			return HRTIMER_RESTART;



		printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",

			this_cpu, duration,

			smp_processor_id(), duration,

			current->comm, task_pid_nr(current));

		print_modules();

		print_irqtrace_events(current);
@@ -309,10 +308,10 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) 
/*

 * The watchdog thread - touches the timestamp.

 */

static int watchdog(void *__bind_cpu)

static int watchdog(void *unused)

{

	struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };

	struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, (unsigned long)__bind_cpu);

	struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);



	sched_setscheduler(current, SCHED_FIFO, &param);
@@ -328,7 +327,7 @@ static int watchdog(void *__bind_cpu) 
	/*

	 * Run briefly once per second to reset the softlockup timestamp.

	 * If this gets delayed for more than 60 seconds then the

	 * debug-printout triggers in softlockup_tick().

	 * debug-printout triggers in watchdog_timer_fn().

	 */

	while (!kthread_should_stop()) {

		__touch_watchdog();

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