[PATCH 2/3] watchdog: update Kconfig entries

From: Don Zickus
Date: Thu Feb 09 2012 - 17:42:53 EST


From: Fernando Luis VÃzquez 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>
Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
---
lib/Kconfig.debug | 18 +++++++++++-------
1 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 63696aa..1e37364 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -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
--
1.7.7.6

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