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

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Message-Id: <1369065716-22801-9-git-send-email-fweisbec@gmail.com>
Date:	Mon, 20 May 2013 18:01:56 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	LKML <linux-kernel@...r.kernel.org>
Cc:	Frederic Weisbecker <fweisbec@...il.com>,
	Don Zickus <dzickus@...hat.com>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Subject: [RFC PATCH 8/8] watchdog: Fix internal state with boot user disabled watchdog

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@...il.com>
Cc: Don Zickus <dzickus@...hat.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
---
 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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