Documentation: document hung_task_panic kernel parameter

This parameter has been around since commit e162b39a368f ("softlockup:
decouple hung tasks check from softlockup detection") in 2009 but was
never documented.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8d24270..5385af5 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1341,12 +1341,21 @@
                        x86-64 are 2M (when the CPU supports "pse") and 1G
                        (when the CPU supports the "pdpe1gb" cpuinfo flag).
 
+       hung_task_panic=
+                       [KNL] Should the hung task detector generate panics.
+                       Format: <integer>
+
+                       A nonzero value instructs the kernel to panic when a
+                       hung task is detected. The default value is controlled
+                       by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
+                       option. The value selected by this boot parameter can
+                       be changed later by the kernel.hung_task_panic sysctl.
+
        hvc_iucv=       [S390]  Number of z/VM IUCV hypervisor console (HVC)
                                terminal devices. Valid values: 0..8
        hvc_iucv_allow= [S390]  Comma-separated list of z/VM user IDs.
                                If specified, z/VM IUCV HVC accepts connections
                                from listed z/VM user IDs only.
-
        keep_bootcon    [KNL]
                        Do not unregister boot console at start. This is only
                        useful for debugging when something happens in the window