diff options
Diffstat (limited to 'kernel/watchdog.c')
| -rw-r--r-- | kernel/watchdog.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index e5e1d85b8c7..69add8a9da6 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -372,6 +372,13 @@ static int watchdog(void *unused) #ifdef CONFIG_HARDLOCKUP_DETECTOR +/* + * 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 cpu0_err; + static int watchdog_nmi_enable(int cpu) { struct perf_event_attr *wd_attr; @@ -390,11 +397,21 @@ static int watchdog_nmi_enable(int cpu) /* Try to register using hardware perf events */ event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL); + + /* save cpu0 error for future comparision */ + if (cpu == 0 && IS_ERR(event)) + cpu0_err = PTR_ERR(event); + if (!IS_ERR(event)) { - pr_info("enabled, takes one hw-pmu counter.\n"); + /* only print for cpu0 or different than cpu0 */ + if (cpu == 0 || cpu0_err) + pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n"); goto out_save; } + /* skip displaying the same error again */ + if (cpu > 0 && (PTR_ERR(event) == cpu0_err)) + return PTR_ERR(event); /* vary the KERN level based on the returned errno */ if (PTR_ERR(event) == -EOPNOTSUPP) @@ -558,7 +575,7 @@ out: /* * Create/destroy watchdog threads as CPUs come and go: */ -static int __cpuinit +static int cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { int hotcpu = (unsigned long)hcpu; @@ -593,10 +610,27 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) return NOTIFY_OK; } -static struct notifier_block __cpuinitdata cpu_nfb = { +static struct notifier_block cpu_nfb = { .notifier_call = cpu_callback }; +#ifdef CONFIG_SUSPEND +/* + * On exit from suspend we force an offline->online transition on the boot CPU + * so that the PMU state that was lost while in suspended state gets set up + * properly for the boot CPU. This information is required for restarting the + * NMI watchdog. + */ +void lockup_detector_bootcpu_resume(void) +{ + void *cpu = (void *)(long)smp_processor_id(); + + cpu_callback(&cpu_nfb, CPU_DEAD_FROZEN, cpu); + cpu_callback(&cpu_nfb, CPU_UP_PREPARE_FROZEN, cpu); + cpu_callback(&cpu_nfb, CPU_ONLINE_FROZEN, cpu); +} +#endif + void __init lockup_detector_init(void) { void *cpu = (void *)(long)smp_processor_id(); |