Currently we do not have a way to enable/disable arch specific
watchdog handlers if it was implemented by any of the architectures.
This patch introduces new function update_arch_nmi_watchdog
which can be used to enable/disable architecture specific NMI
watchdog handlers. Also exposes watchdog_enabled variable outside
so that arch specific nmi watchdogs can use it to implement
enalbe/disable behavour.
Signed-off-by: Babu Moger <babu.mo...@oracle.com>
---
include/linux/nmi.h | 1 +
kernel/watchdog.c | 16 +++++++++++++---
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 4630eea..01b4830 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -66,6 +66,7 @@ static inline bool trigger_allbutself_cpu_backtrace(void)
#ifdef CONFIG_LOCKUP_DETECTOR
u64 hw_nmi_get_sample_period(int watchdog_thresh);
+extern unsigned long watchdog_enabled;
extern int nmi_watchdog_enabled;
extern int soft_watchdog_enabled;
extern int watchdog_user_enabled;
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9acb29f..1ac2814 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -46,16 +46,21 @@
static DEFINE_MUTEX(watchdog_proc_mutex);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static unsigned long __read_mostly watchdog_enabled =
SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
+#if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG)
+unsigned long __read_mostly watchdog_enabled =
SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
#else
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
#endif
int __read_mostly nmi_watchdog_enabled;
int __read_mostly soft_watchdog_enabled;
int __read_mostly watchdog_user_enabled;
int __read_mostly watchdog_thresh = 10;
+/*
+ * Implemented by arch specific handlers if it defines CONFIG_HAVE_NMI_WATCHDOG
+ */
+void __weak update_arch_nmi_watchdog(void) {}
+
#ifdef CONFIG_SMP
int __read_mostly sysctl_softlockup_all_cpu_backtrace;
int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
@@ -842,6 +847,11 @@ static int proc_watchdog_update(void)
int err = 0;
/*
+ * Enable/Disable arch specific nmi watchdogs if there is one
+ */
+ update_arch_nmi_watchdog();
+
+ /*
* Watchdog threads won't be started if they are already active.
* The 'watchdog_running' variable in watchdog_*_all_cpus() takes
* care of this. If those threads are already active, the sample
--
1.7.1
