Commit 1409f141 authored Apr 27, 2011 by Hillf Danton Committed by Linus Torvalds Apr 28, 2011

kernel/watchdog.c: disable nmi perf event in the error path of enabling watchdog



In corner cases where softlockup watchdog is not setup successfully, the
relevant nmi perf event for hardlockup watchdog could be disabled, then
the status of the underlying hardware remains unchanged.

Also, if the kthread doesn't start then the hrtimer won't run and the
hardlockup detector will falsely fire.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 534e3adb

kernel/watchdog.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -430,9 +430,12 @@ static int watchdog_enable(int cpu)
		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);
		if (!err)
		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);