softlockup: allow panic on lockup
allow users to configure the softlockup detector to generate a panic
instead of a warning message.
high-availability systems might opt for this strict method (combined
with panic_timeout= boot option/sysctl), instead of generating
softlockup warnings ad infinitum.
also, automated tests work better if the system reboots reliably (into
a safe kernel) in case of a lockup.
The full spectrum of configurability is supported: boot option, sysctl
option and Kconfig option.
it's default-disabled.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 01b6522..78e0ad2 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -27,6 +27,21 @@
static int __read_mostly did_panic;
unsigned long __read_mostly softlockup_thresh = 60;
+/*
+ * Should we panic (and reboot, if panic_timeout= is set) when a
+ * soft-lockup occurs:
+ */
+unsigned int __read_mostly softlockup_panic =
+ CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
+
+static int __init softlockup_panic_setup(char *str)
+{
+ softlockup_panic = simple_strtoul(str, NULL, 0);
+
+ return 1;
+}
+__setup("softlockup_panic=", softlockup_panic_setup);
+
static int
softlock_panic(struct notifier_block *this, unsigned long event, void *ptr)
{
@@ -120,6 +135,9 @@
else
dump_stack();
spin_unlock(&print_lock);
+
+ if (softlockup_panic)
+ panic("softlockup: hung tasks");
}
/*
@@ -172,6 +190,9 @@
t->last_switch_timestamp = now;
touch_nmi_watchdog();
+
+ if (softlockup_panic)
+ panic("softlockup: blocked tasks");
}
/*