diff options
| -rw-r--r-- | kernel/watchdog.c | 15 | ||||
| -rw-r--r-- | kernel/watchdog_hld.c | 20 |
2 files changed, 7 insertions, 28 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 1c185d9dd468..af000956286c 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -485,21 +485,6 @@ static void watchdog(unsigned int cpu) __this_cpu_write(soft_lockup_hrtimer_cnt, __this_cpu_read(hrtimer_interrupts)); __touch_watchdog(); - - /* - * watchdog_nmi_enable() clears the NMI_WATCHDOG_ENABLED bit in the - * failure path. Check for failures that can occur asynchronously - - * for example, when CPUs are on-lined - and shut down the hardware - * perf event on each CPU accordingly. - * - * The only non-obvious place this bit can be cleared is through - * watchdog_nmi_enable(), so a pr_info() is placed there. Placing a - * pr_info here would be too noisy as it would result in a message - * every few seconds if the hardlockup was disabled but the softlockup - * enabled. - */ - if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED)) - watchdog_nmi_disable(cpu); } static struct smp_hotplug_thread watchdog_threads = { diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index c9586ebc2e98..7b602714ea53 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -23,6 +23,7 @@ static DEFINE_PER_CPU(bool, watchdog_nmi_touch); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); static unsigned long hardlockup_allcpu_dumped; +static bool hardlockup_detector_disabled; void arch_touch_nmi_watchdog(void) { @@ -178,6 +179,10 @@ int watchdog_nmi_enable(unsigned int cpu) 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; @@ -206,18 +211,6 @@ int watchdog_nmi_enable(unsigned int cpu) goto out_save; } - /* - * Disable the hard lockup detector if _any_ CPU fails to set up - * set up the hardware perf event. The watchdog() function checks - * the NMI_WATCHDOG_ENABLED bit periodically. - * - * The barriers are for syncing up watchdog_enabled across all the - * cpus, as clear_bit() does not use barriers. - */ - smp_mb__before_atomic(); - clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled); - smp_mb__after_atomic(); - /* skip displaying the same error again */ if (!firstcpu && (PTR_ERR(event) == firstcpu_err)) return PTR_ERR(event); @@ -232,7 +225,8 @@ int watchdog_nmi_enable(unsigned int cpu) pr_err("disabled (cpu%i): unable to create perf event: %ld\n", cpu, PTR_ERR(event)); - pr_info("Shutting down hard lockup detector on all cpus\n"); + pr_info("Disabling hard lockup detector permanently\n"); + hardlockup_detector_disabled = true; return PTR_ERR(event); |