From 11295055526308ee71d82dc97f0a9ca2dd61c3b9 Mon Sep 17 00:00:00 2001 From: Laurence Oberman Date: Thu, 1 Nov 2018 09:30:18 -0400 Subject: watchdog/core: Add watchdog_thresh command line parameter The hard and soft lockup detector threshold has a default value of 10 seconds which can only be changed via sysctl. During early boot lockup detection can trigger when noisy debugging emits a large amount of messages to the console, but there is no way to set a larger threshold on the kernel command line. The detector can only be completely disabled. Add a new watchdog_thresh= command line parameter to allow boot time control over the threshold. It works in the same way as the sysctl and affects both the soft and the hard lockup detectors. Signed-off-by: Laurence Oberman Signed-off-by: Thomas Gleixner Cc: rdunlap@infradead.org Cc: prarit@redhat.com Link: https://lkml.kernel.org/r/1541079018-13953-1-git-send-email-loberman@redhat.com --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++ kernel/watchdog.c | 7 +++++++ 2 files changed, 15 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b90fe3b6bc6c..79b5b473001b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4957,6 +4957,14 @@ or other driver-specific files in the Documentation/watchdog/ directory. + watchdog_thresh= + [KNL] + Set the hard lockup detector stall duration + threshold in seconds. The soft lockup detector + threshold is set to twice the value. A value of 0 + disables both lockup detectors. Default is 10 + seconds. + workqueue.watchdog_thresh= If CONFIG_WQ_WATCHDOG is configured, workqueue can warn stall conditions and dump internal state to diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 977918d5d350..8fbfda94a67b 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -199,6 +199,13 @@ static int __init nosoftlockup_setup(char *str) } __setup("nosoftlockup", nosoftlockup_setup); +static int __init watchdog_thresh_setup(char *str) +{ + get_option(&str, &watchdog_thresh); + return 1; +} +__setup("watchdog_thresh=", watchdog_thresh_setup); + #ifdef CONFIG_SMP int __read_mostly sysctl_softlockup_all_cpu_backtrace; -- cgit v1.2.3