From: Don Zickus <dzickus@redhat.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: "Ingo Molnar" <mingo@elte.hu>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Fernando Luis Vázquez Cao" <fernando@oss.ntt.co.jp>,
"Don Zickus" <dzickus@redhat.com>
Subject: [PATCH 2/3] watchdog: update Kconfig entries
Date: Thu, 9 Feb 2012 17:42:21 -0500 [thread overview]
Message-ID: <1328827342-6253-2-git-send-email-dzickus@redhat.com> (raw)
In-Reply-To: <1328827342-6253-1-git-send-email-dzickus@redhat.com>
From: Fernando Luis Vázquez Cao <fernando@oss.ntt.co.jp>
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@oss.ntt.co.jp>
Signed-off-by: Don Zickus <dzickus@redhat.com>
---
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
next prev parent reply other threads:[~2012-02-09 22:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-09 22:42 [PATCH 1/3] watchdog: update documentation Don Zickus
2012-02-09 22:42 ` Don Zickus [this message]
2012-02-11 23:07 ` [tip:perf/core] watchdog: Update Kconfig entries tip-bot for Fernando Luis Vázquez Cao
2012-02-09 22:42 ` [PATCH 3/3] watchdog: fix code/comments mismatches Don Zickus
2012-02-11 23:08 ` [tip:perf/core] watchdog: Fix " tip-bot for Fernando Luis Vázquez Cao
2012-02-11 23:06 ` [tip:perf/core] watchdog: Update documentation tip-bot for Fernando Luis Vázquez Cao
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