On Wed, 14 Jun 2017 21:16:04 -0500
Babu Moger <babu.moger@xxxxxxxxxx> wrote:
> Hi Don,
>
> On 6/14/2017 9:09 AM, Don Zickus wrote:
> > On Wed, Jun 14, 2017 at 02:11:18AM +1000, Nicholas Piggin wrote:
> >>> Yeah, if you wouldn't mind. Sorry for dragging this out, but I feel like we
> >>> are getting close to have this defined properly which would allow us to
> >>> split the code up correctly in the future.
> >> How's this for a replacement patch 3? I think the Kconfig works out much
> >> better now.
> > Hi Nick,
> >
> > I think you made this much clearer, thank you! I am good with this.
> >
> >
> > Hi Babu,
> >
> > Can you give this patchset (and particularly this version of patch 3) a try
> > on sparc to make sure we didn't break anything? I believe this should
> > resolve the start nmi watchdog on boot issue you noticed. Thanks!
>
> There is still one problem with the patch.
>
> # cat /proc/sys/kernel/watchdog
> 1
> # cat /proc/sys/kernel/nmi_watchdog
> 0
>
> Problem is setting the initial value for "nmi_watchdog"
>
> We need something(or similar) patch on top to address this.
> ============================================
> diff --git a/kernel/watchdog.c b/kernel/watchdog.c
> index 5397c63..0105856 100644
> --- a/kernel/watchdog.c
> +++ b/kernel/watchdog.c
> @@ -34,9 +34,13 @@
>
> int __read_mostly nmi_watchdog_enabled;
>
> -#ifdef CONFIG_HARDLOCKUP_DETECTOR
> +#if defined(CONFIG_HARDLOCKUP_DETECTOR) ||
> defined(CONFIG_HAVE_NMI_WATCHDOG)
> unsigned long __read_mostly watchdog_enabled =
> SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
> +#else
> +unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
> +#endif
>
> +#ifdef CONFIG_HARDLOCKUP_DETECTOR
> /* boot commands */
> /*
> * Should we panic when a soft-lockup or hard-lockup occurs:
> @@ -69,9 +73,6 @@ static int __init hardlockup_panic_setup(char *str)
> return 1;
> }
> __setup("nmi_watchdog=", hardlockup_panic_setup);
> -
> -#else
> -unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
> #endif
>
> #ifdef CONFIG_SOFTLOCKUP_DETECTOR
Hmm, I guess I missed this because sparc parses nmi_watchdog=, but it
also relies on the watchdog_enabled value.
I guess I can fold your incremental patch in. I hope we could get
sparc quickly to adopt the complate HAVE_HARDLOCKUP_DETECTOR_ARCH soon
afterwards though, so we only have 2 cases -- complete hardlockup
detector, or the very bare minimum NMI_WATCHDOG.
Thanks,
Nick
