diff options
Diffstat (limited to 'kernel/watchdog.c')
| -rw-r--r-- | kernel/watchdog.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index f37f974aa81..14733d4d156 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -48,12 +48,15 @@ static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); * Should we panic when a soft-lockup or hard-lockup occurs: */ #ifdef CONFIG_HARDLOCKUP_DETECTOR -static int hardlockup_panic; +static int hardlockup_panic = + CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE; static int __init hardlockup_panic_setup(char *str) { if (!strncmp(str, "panic", 5)) hardlockup_panic = 1; + else if (!strncmp(str, "nopanic", 7)) + hardlockup_panic = 0; else if (!strncmp(str, "0", 1)) watchdog_enabled = 0; return 1; @@ -363,8 +366,14 @@ static int watchdog_nmi_enable(int cpu) goto out_save; } - printk(KERN_ERR "NMI watchdog disabled for cpu%i: unable to create perf event: %ld\n", - cpu, PTR_ERR(event)); + + /* vary the KERN level based on the returned errno */ + if (PTR_ERR(event) == -EOPNOTSUPP) + printk(KERN_INFO "NMI watchdog disabled (cpu%i): not supported (no LAPIC?)\n", cpu); + else if (PTR_ERR(event) == -ENOENT) + printk(KERN_WARNING "NMI watchdog disabled (cpu%i): hardware events not enabled\n", cpu); + else + printk(KERN_ERR "NMI watchdog disabled (cpu%i): unable to create perf event: %ld\n", cpu, PTR_ERR(event)); return PTR_ERR(event); /* success path */ @@ -409,19 +418,25 @@ static int watchdog_prepare_cpu(int cpu) static int watchdog_enable(int cpu) { struct task_struct *p = per_cpu(softlockup_watchdog, cpu); - int err; + int err = 0; /* enable the perf event */ err = watchdog_nmi_enable(cpu); - if (err) - return err; + + /* Regardless of err above, fall through and start softlockup */ /* create the watchdog thread */ if (!p) { p = kthread_create(watchdog, (void *)(unsigned long)cpu, "watchdog/%d", cpu); if (IS_ERR(p)) { printk(KERN_ERR "softlockup watchdog for %i failed\n", cpu); - return PTR_ERR(p); + if (!err) { + /* if hardlockup hasn't already set this */ + err = PTR_ERR(p); + /* and disable the perf event */ + watchdog_nmi_disable(cpu); + } + goto out; } kthread_bind(p, cpu); per_cpu(watchdog_touch_ts, cpu) = 0; @@ -429,7 +444,8 @@ static int watchdog_enable(int cpu) wake_up_process(p); } - return 0; +out: + return err; } static void watchdog_disable(int cpu) @@ -541,7 +557,13 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) break; #endif /* CONFIG_HOTPLUG_CPU */ } - return notifier_from_errno(err); + + /* + * hardlockup and softlockup are not important enough + * to block cpu bring up. Just always succeed and + * rely on printk output to flag problems. + */ + return NOTIFY_OK; } static struct notifier_block __cpuinitdata cpu_nfb = { |