diff --git a/kernel/watchdog.c b/kernel/watchdog.c index fd8a998eb197..5eb11960e4a2 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -107,6 +107,7 @@ __setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup); */ int __weak watchdog_nmi_enable(unsigned int cpu) { + hardlockup_detector_perf_enable(); return 0; } @@ -465,7 +466,8 @@ static void watchdog_enable(unsigned int cpu) /* Initialize timestamp */ __touch_watchdog(); /* Enable the perf event */ - watchdog_nmi_enable(cpu); + if (watchdog_enabled & NMI_WATCHDOG_ENABLED) + watchdog_nmi_enable(cpu); watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1); } diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 99a3f22e48cc..509bb6b59c41 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -25,7 +25,7 @@ static DEFINE_PER_CPU(struct perf_event *, dead_event); static struct cpumask dead_events_mask; static unsigned long hardlockup_allcpu_dumped; -static bool hardlockup_detector_disabled; +static unsigned int watchdog_cpus; void arch_touch_nmi_watchdog(void) { @@ -160,84 +160,6 @@ static void watchdog_overflow_callback(struct perf_event *event, return; } -/* - * People like the simple clean cpu node info on boot. - * Reduce the watchdog noise by only printing messages - * that are different from what cpu0 displayed. - */ -static unsigned long firstcpu_err; -static atomic_t watchdog_cpus; - -int watchdog_nmi_enable(unsigned int cpu) -{ - struct perf_event_attr *wd_attr; - struct perf_event *event = per_cpu(watchdog_ev, cpu); - int firstcpu = 0; - - /* nothing to do if the hard lockup detector is disabled */ - if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) - goto out; - - /* A failure disabled the hardlockup detector permanently */ - if (hardlockup_detector_disabled) - return -ENODEV; - - /* is it already setup and enabled? */ - if (event && event->state > PERF_EVENT_STATE_OFF) - goto out; - - /* it is setup but not enabled */ - if (event != NULL) - goto out_enable; - - if (atomic_inc_return(&watchdog_cpus) == 1) - firstcpu = 1; - - wd_attr = &wd_hw_attr; - wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh); - - /* Try to register using hardware perf events */ - event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL); - - /* save the first cpu's error for future comparision */ - if (firstcpu && IS_ERR(event)) - firstcpu_err = PTR_ERR(event); - - if (!IS_ERR(event)) { - /* only print for the first cpu initialized */ - if (firstcpu || firstcpu_err) - pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n"); - goto out_save; - } - - /* skip displaying the same error again */ - if (!firstcpu && (PTR_ERR(event) == firstcpu_err)) - return PTR_ERR(event); - - /* vary the KERN level based on the returned errno */ - if (PTR_ERR(event) == -EOPNOTSUPP) - pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu); - else if (PTR_ERR(event) == -ENOENT) - pr_warn("disabled (cpu%i): hardware events not enabled\n", - cpu); - else - pr_err("disabled (cpu%i): unable to create perf event: %ld\n", - cpu, PTR_ERR(event)); - - pr_info("Disabling hard lockup detector permanently\n"); - hardlockup_detector_disabled = true; - - return PTR_ERR(event); - - /* success path */ -out_save: - per_cpu(watchdog_ev, cpu) = event; -out_enable: - perf_event_enable(per_cpu(watchdog_ev, cpu)); -out: - return 0; -} - static int hardlockup_detector_event_create(void) { unsigned int cpu = smp_processor_id(); @@ -267,6 +189,9 @@ void hardlockup_detector_perf_enable(void) if (hardlockup_detector_event_create()) return; + if (!watchdog_cpus++) + pr_info("Enabled. Permanently consumes one hw-PMU counter.\n"); + perf_event_enable(this_cpu_read(watchdog_ev)); } @@ -282,10 +207,7 @@ void hardlockup_detector_perf_disable(void) this_cpu_write(watchdog_ev, NULL); this_cpu_write(dead_event, event); cpumask_set_cpu(smp_processor_id(), &dead_events_mask); - - /* watchdog_nmi_enable() expects this to be zero initially. */ - if (atomic_dec_and_test(&watchdog_cpus)) - firstcpu_err = 0; + watchdog_cpus--; } }