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: Don 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: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 17 insertions, 18 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e53622c1465e..91b0b26adc67 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -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();