[PATCH] V3 init/main.c Enable watchdog_thresh control from kernel line

From: Laurence Oberman
Date: Wed Oct 24 2018 - 12:53:55 EST


Both graphics and serial consoles are exposed to hard lockups
when handling a large amount of messaging. The kernel watchdog_thresh
parameter up to now has not been available to be set on the kernel line for
early boot.
This patch allows the setting of watchdog_thresh to be increased
when needed to avoid the hard lockups in the console code.

Signed-off-by: Laurence Oberman <loberman@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++
init/main.c | 9 +++++++++
2 files changed, 17 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4cdcd1a..cd8d588 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4932,6 +4932,14 @@
or other driver-specific files in the
Documentation/watchdog/ directory.

+ watchdog_thresh=
+ This parameter is now available as a kernel line
+ parameter. Use watchdog_thresh=30 as example
+ This will allow early boot changes of the current
+ default of 10s to be increased when needed to
+ avoid hard lockups.
+ Default: 10
+
workqueue.watchdog_thresh=
If CONFIG_WQ_WATCHDOG is configured, workqueue can
warn stall conditions and dump internal state to
diff --git a/init/main.c b/init/main.c
index 1c3f902..88cbed9 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1038,6 +1038,15 @@ static int __init set_debug_rodata(char *str)
__setup("rodata=", set_debug_rodata);
#endif

+static int __init
+is_watchdog_thresh_setup(char *str)
+{
+ get_option(&str, &watchdog_thresh);
+ return 1;
+}
+__setup("watchdog_thresh=", is_watchdog_thresh_setup);
+
+
#ifdef CONFIG_STRICT_KERNEL_RWX
static void mark_readonly(void)
{
--
1.8.3.1