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authorDimitri Sivanich <sivanich@sgi.com>2008-05-12 21:21:14 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-25 06:35:03 +0200
commit9383d9679056e6cc4e7ff70f31da945a268238f4 (patch)
treec6678a8c4e0fed0739e43f24b608d51856af6f1f /kernel/softlockup.c
parent9c44bc03fff44ff04237a7d92e35304a0e50c331 (diff)
downloadlinux-9383d9679056e6cc4e7ff70f31da945a268238f4.tar.gz
softlockup: fix softlockup_thresh unaligned access and disable detection at runtime
Fix unaligned access errors when setting softlockup_thresh on
64 bit platforms.

Allow softlockup detection to be disabled by setting
softlockup_thresh <= 0.

Detect that boot time softlockup detection has been disabled
earlier in softlockup_tick.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/softlockup.c')
-rw-r--r--kernel/softlockup.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 78e0ad21cb0c..a3a0b239b7f7 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -25,7 +25,7 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp);
 static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
 
 static int __read_mostly did_panic;
-unsigned long __read_mostly softlockup_thresh = 60;
+int __read_mostly softlockup_thresh = 60;
 
 /*
  * Should we panic (and reboot, if panic_timeout= is set) when a
@@ -94,6 +94,14 @@ void softlockup_tick(void)
 	struct pt_regs *regs = get_irq_regs();
 	unsigned long now;
 
+	/* Is detection switched off? */
+	if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) {
+		/* Be sure we don't false trigger if switched back on */
+		if (touch_timestamp)
+			per_cpu(touch_timestamp, this_cpu) = 0;
+		return;
+	}
+
 	if (touch_timestamp == 0) {
 		touch_softlockup_watchdog();
 		return;
@@ -104,7 +112,7 @@ void softlockup_tick(void)
 	/* report at most once a second */
 	if ((print_timestamp >= touch_timestamp &&
 			print_timestamp < (touch_timestamp + 1)) ||
-			did_panic || !per_cpu(watchdog_task, this_cpu)) {
+			did_panic) {
 		return;
 	}