From 55537871ef666b4153fd1ef8782e4a13fee142cc Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Thu, 5 Nov 2015 18:44:41 -0800 Subject: kernel/watchdog.c: perform all-CPU backtrace in case of hard lockup In many cases of hardlockup reports, it's actually not possible to know why it triggered, because the CPU that got stuck is usually waiting on a resource (with IRQs disabled) in posession of some other CPU is holding. IOW, we are often looking at the stacktrace of the victim and not the actual offender. Introduce sysctl / cmdline parameter that makes it possible to have hardlockup detector perform all-CPU backtrace. Signed-off-by: Jiri Kosina Reviewed-by: Aaron Tomlin Cc: Ulrich Obergfell Acked-by: Don Zickus Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/nmi.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 78488e099ce7..7ec5b86735f3 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -73,6 +73,7 @@ extern int watchdog_user_enabled; extern int watchdog_thresh; extern unsigned long *watchdog_cpumask_bits; extern int sysctl_softlockup_all_cpu_backtrace; +extern int sysctl_hardlockup_all_cpu_backtrace; struct ctl_table; extern int proc_watchdog(struct ctl_table *, int , void __user *, size_t *, loff_t *); -- cgit