Hi, On 3/23/20 2:46 PM, Guilherme G. Piccoli wrote: > > .../admin-guide/kernel-parameters.txt | 6 ++++ > Documentation/admin-guide/sysctl/kernel.rst | 15 ++++++++++ > include/linux/sched/sysctl.h | 7 +++++ > kernel/hung_task.c | 30 +++++++++++++++++-- > kernel/sysctl.c | 11 +++++++ > 5 files changed, 67 insertions(+), 2 deletions(-) > admin-guide/kernel-parameters.txt predominantly uses "CPUs" for plural CPUs when not part of a cmdline keyword etc., so please adjust below: > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index c07815d230bc..7a14caac6c94 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1453,6 +1453,12 @@ > x86-64 are 2M (when the CPU supports "pse") and 1G > (when the CPU supports the "pdpe1gb" cpuinfo flag). > > + hung_task_all_cpu_backtrace= > + [KNL] Should kernel generate backtraces on all cpus CPUs > + when a hung task is detected. Defaults to 0 and can > + be controlled by hung_task_all_cpu_backtrace sysctl. > + Format: <integer> > + > hung_task_panic= > [KNL] Should the hung task detector generate panics. > Format: <integer> > diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst > index def074807cee..8b4ff69d2348 100644 > --- a/Documentation/admin-guide/sysctl/kernel.rst > +++ b/Documentation/admin-guide/sysctl/kernel.rst > @@ -40,6 +40,7 @@ show up in /proc/sys/kernel: > - hotplug > - hardlockup_all_cpu_backtrace > - hardlockup_panic > +- hung_task_all_cpu_backtrace > - hung_task_panic > - hung_task_check_count > - hung_task_timeout_secs > @@ -338,6 +339,20 @@ Path for the hotplug policy agent. > Default value is "/sbin/hotplug". > > > +hung_task_all_cpu_backtrace: > +================ > + > +If this option is set, the kernel will send an NMI to all CPUs to dump > +their backtraces when a hung task is detected. This file shows up if > +CONFIG_DETECT_HUNG_TASK and CONFIG_SMP are enabled. > + > +0: Won't show all CPUs backtraces when a hung task is detected. > +This is the default behavior. > + > +1: Will non-maskably interrupt all CPUs and dump their backtraces when > +a hung task is detected. > + > + > hung_task_panic: > ================ > thanks. -- ~Randy
