[PATCH] watchdog: update Kconfig entries

From: Fernando Luis Vázquez Cao
Date: Wed Feb 08 2012 - 20:42:19 EST


Hi Don,

Could you pick up the attached patch too?

Thanks,
Fernando
Subject: [PATCH] watchdog: update Kconfig entries

From: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx>

The soft and hard lockup thresholds have changed so the corresponding Kconfig
entries need to be updated accordingly. Add a reference to watchdog_thresh
while at it.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx>
---

diff -urNp linux-3.2.5-orig/lib/Kconfig.debug linux-3.2.5/lib/Kconfig.debug
--- linux-3.2.5-orig/lib/Kconfig.debug 2012-01-05 08:55:44.000000000 +0900
+++ linux-3.2.5/lib/Kconfig.debug 2012-02-09 10:30:06.781625497 +0900
@@ -166,18 +166,21 @@ config LOCKUP_DETECTOR
hard and soft lockups.

Softlockups are bugs that cause the kernel to loop in kernel
- mode for more than 60 seconds, without giving other tasks a
+ mode for more than 20 seconds, without giving other tasks a
chance to run. The current stack trace is displayed upon
detection and the system will stay locked up.

Hardlockups are bugs that cause the CPU to loop in kernel mode
- for more than 60 seconds, without letting other interrupts have a
+ for more than 10 seconds, without letting other interrupts have a
chance to run. The current stack trace is displayed upon detection
and the system will stay locked up.

The overhead should be minimal. A periodic hrtimer runs to
- generate interrupts and kick the watchdog task every 10-12 seconds.
- An NMI is generated every 60 seconds or so to check for hardlockups.
+ generate interrupts and kick the watchdog task every 4 seconds.
+ An NMI is generated every 10 seconds or so to check for hardlockups.
+
+ The frequency of hrtimer and NMI events and the soft and hard lockup
+ thresholds can be controlled through the sysctl watchdog_thresh.

config HARDLOCKUP_DETECTOR
def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
@@ -189,7 +192,8 @@ config BOOTPARAM_HARDLOCKUP_PANIC
help
Say Y here to enable the kernel to panic on "hard lockups",
which are bugs that cause the kernel to loop in kernel
- mode with interrupts disabled for more than 60 seconds.
+ mode with interrupts disabled for more than 10 seconds (configurable
+ using the watchdog_thresh sysctl).

Say N if unsure.

@@ -206,8 +210,8 @@ config BOOTPARAM_SOFTLOCKUP_PANIC
help
Say Y here to enable the kernel to panic on "soft lockups",
which are bugs that cause the kernel to loop in kernel
- mode for more than 60 seconds, without giving other tasks a
- chance to run.
+ mode for more than 20 seconds (configurable using the watchdog_thresh
+ sysctl), without giving other tasks a chance to run.

The panic can be used in combination with panic_timeout,
to cause the system to reboot automatically after a