[RFC PATCH 8/8] watchdog: Fix internal state with boot user disabled watchdog

From: Frederic Weisbecker
Date: Mon May 20 2013 - 12:02:32 EST


When the watchdog is disabled through the 'nmi_watchdog=0'
boot parameter, the watchdog_running internal state isn't
cleared. Hence further enablements through sysctl/procfs
are ignored because the subsystem spuriously thinks it's
already running.

Initialize it properly on boot.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Don Zickus <dzickus@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
kernel/watchdog.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 10776fe..3fa5df20 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -31,7 +31,7 @@

int watchdog_user_enabled = 1;
int __read_mostly watchdog_thresh = 10;
-static int __read_mostly watchdog_running = 1;
+static int __read_mostly watchdog_running;
static u64 __read_mostly sample_period;

static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
@@ -545,10 +545,10 @@ void __init lockup_detector_init(void)
{
#ifdef CONFIG_NO_HZ_FULL
watchdog_user_enabled = 0;
- watchdog_running = 0;
pr_warning("Disabled lockup detectors by default because of full dynticks\n");
pr_warning("You can overwrite that with 'sysctl -w kernel.watchdog=1'\n");
#endif
+ watchdog_running = watchdog_user_enabled;
set_sample_period();
if (smpboot_register_percpu_thread(&watchdog_threads)) {
pr_err("Failed to create watchdog threads, disabled\n");
--
1.7.5.4

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