kernel/watchdog.c: allow hardlockup to panic by default
When a cpu is considered stuck, instead of limping along and just printing
a warning, it is sometimes preferred to just panic, let kdump capture the
vmcore and reboot. This gets the machine back into a stable state quickly
while saving the info that got it into a stuck state to begin with.
Add a Kconfig option to allow users to set the hardlockup to panic
by default. Also add in a 'nmi_watchdog=nopanic' to override this.
[akpm@linux-foundation.org: fix strncmp length]
Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 191c5c4..fb0afef 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -171,6 +171,23 @@
def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
!ARCH_HAS_NMI_WATCHDOG
+config BOOTPARAM_HARDLOCKUP_PANIC
+ bool "Panic (Reboot) On Hard Lockups"
+ depends on LOCKUP_DETECTOR
+ help
+ Say Y here to enable the kernel to panic on "hard lockups",
+ which are bugs that cause the kernel to loop in kernel
+ mode with interrupts disabled for more than 60 seconds.
+
+ Say N if unsure.
+
+config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
+ int
+ depends on LOCKUP_DETECTOR
+ range 0 1
+ default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
+ default 1 if BOOTPARAM_HARDLOCKUP_PANIC
+
config BOOTPARAM_SOFTLOCKUP_PANIC
bool "Panic (Reboot) On Soft Lockups"
depends on LOCKUP_DETECTOR