watchdog: Document watchdog_thresh sysctl
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/51959678.6000802@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index ccd4258..e8fabd6 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -76,6 +76,7 @@
- tainted
- threads-max
- unknown_nmi_panic
+- watchdog_thresh
- version
==============================================================
@@ -648,3 +649,16 @@
NMI switch that most IA32 servers have fires unknown NMI up, for
example. If a system hangs up, try pressing the NMI switch.
+
+==============================================================
+
+watchdog_thresh:
+
+This value can be used to control the frequency of hrtimer and NMI
+events and the soft and hard lockup thresholds. The default threshold
+is 10 seconds.
+
+The softlockup threshold is (2 * watchdog_thresh). Setting this
+tunable to zero will disable lockup detection altogether.
+
+==============================================================