Messages in this thread | | | Date | Thu, 15 Apr 2010 15:32:51 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH v2] [watchdog] combine nmi_watchdog and softlockup |
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On Thu, 15 Apr 2010 17:25:10 -0400 Don Zickus wrote:
> arch/x86/kernel/apic/hw_nmi.c | 2 +- > include/linux/sched.h | 6 + > init/Kconfig | 1 + > kernel/Makefile | 4 +- > kernel/sysctl.c | 9 + > kernel/watchdog.c | 570 +++++++++++++++++++++++++++++++++++++++++ > lib/Kconfig.debug | 21 +- > 7 files changed, 605 insertions(+), 8 deletions(-) > create mode 100644 kernel/watchdog.c
Updates to Documentation/kernel-parameters.txt ??
> +static int __init no_watchdog_setup(char *str) > +{ > + no_watchdog = 1; > + return 1; > +} > +__setup("no_watchdog", no_watchdog_setup);
New, please document.
> +/* deprecated */ > +static int __init nosoftlockup_setup(char *str) > +{ > + no_watchdog = 1; > + return 1; > +}
That's not marked as deprecated anywhere?
> +__setup("nosoftlockup", nosoftlockup_setup); > +static int __init nonmi_watchdog_setup(char *str) > +{ > + no_watchdog = 1; > + return 1; > +} > +__setup("nonmi_watchdog", nonmi_watchdog_setup);
New, please document.
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index e2e73cc..280794a 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -171,15 +171,24 @@ config DETECT_SOFTLOCKUP > support it.) > > config NMI_WATCHDOG > - bool "Detect Hard Lockups with an NMI Watchdog" > - depends on DEBUG_KERNEL && PERF_EVENTS && PERF_EVENTS_NMI > + bool "Detect Hard and Soft Lockups" > + depends on DEBUG_KERNEL > + default DETECT_SOFTLOCKUP > help > Say Y here to enable the kernel to use the NMI as a watchdog > - to detect hard lockups. This is useful when a cpu hangs for no
preferably: CPU
> - reason but can still respond to NMIs. A backtrace is displayed > - for reviewing and reporting. > + to detect 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 > + 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
ditto
> + for more than 60 seconds, without letting other interrupts a
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, just an extra NMI every few > + The overhead should me minimal, just an extra NMI every few
be
> seconds. > > config BOOTPARAM_SOFTLOCKUP_PANIC
--- ~Randy
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