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-rw-r--r--kernel/watchdog.c27
1 files changed, 20 insertions, 7 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 18bb15776c5..140dce75045 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;
@@ -415,19 +418,22 @@ 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);
+ goto out;
}
kthread_bind(p, cpu);
per_cpu(watchdog_touch_ts, cpu) = 0;
@@ -435,7 +441,8 @@ static int watchdog_enable(int cpu)
wake_up_process(p);
}
- return 0;
+out:
+ return err;
}
static void watchdog_disable(int cpu)
@@ -547,7 +554,13 @@ 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 = {