From: Don Zickus Date: Mon, 17 May 2010 22:06:04 +0000 (-0400) Subject: lockup_detector: Convert per_cpu to __get_cpu_var for readability X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=26e09c6eee14f4827b55137ba0eedc4e77cd50ab;p=linux-beck.git 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 Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Don Zickus Cc: Cyrill Gorcunov LKML-Reference: <1274133966-18415-2-git-send-email-dzickus@redhat.com> Signed-off-by: Frederic Weisbecker --- 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, ¶m); @@ -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();