On Wed, Feb 27, 2019 at 08:05:13AM -0800, Ricardo Neri wrote:
> CPU architectures that have an NMI watchdog use arch_touch_nmi_watchdog()
> to briefly ignore the hardlockup detector. If the architecture does not
> have an NMI watchdog, one can be constructed using a source of non-
> maskable interrupts. In this case, arch_touch_nmi_watchdog() is common
> to any underlying hardware resource used to drive the detector and needs
> to be available to other kernel subsystems if hardware different from perf
> drives the detector.
>
> There exists perf-based and HPET-based implementations. Make it available
> to the latter.
>
> For clarity, wrap this function in a separate preprocessor conditional
> from functions which are truly specific to the perf-based implementation.
>
> Cc: "H. Peter Anvin" <[email protected]>
> Cc: Ashok Raj <[email protected]>
> Cc: Andi Kleen <[email protected]>
> Cc: Tony Luck <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
> Cc: Don Zickus <[email protected]>
> Cc: Nicholas Piggin <[email protected]>
> Cc: Michael Ellerman <[email protected]>
> Cc: Frederic Weisbecker <[email protected]>
> Cc: Alexei Starovoitov <[email protected]>
> Cc: Babu Moger <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Paul Mackerras <[email protected]>
> Cc: Mathieu Desnoyers <[email protected]>
> Cc: Masami Hiramatsu <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Philippe Ombredanne <[email protected]>
> Cc: Colin Ian King <[email protected]>
> Cc: Byungchul Park <[email protected]>
> Cc: "Paul E. McKenney" <[email protected]>
> Cc: "Luis R. Rodriguez" <[email protected]>
> Cc: Waiman Long <[email protected]>
> Cc: Josh Poimboeuf <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Davidlohr Bueso <[email protected]>
> Cc: Christoffer Dall <[email protected]>
> Cc: Marc Zyngier <[email protected]>
> Cc: Kai-Heng Feng <[email protected]>
> Cc: Konrad Rzeszutek Wilk <[email protected]>
> Cc: David Rientjes <[email protected]>
> Cc: "Ravi V. Shankar" <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Ricardo Neri <[email protected]>
> ---
> include/linux/nmi.h | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/nmi.h b/include/linux/nmi.h
> index 5a8b19749769..bf5ebcfdd590 100644
> --- a/include/linux/nmi.h
> +++ b/include/linux/nmi.h
> @@ -94,8 +94,16 @@ static inline void hardlockup_detector_disable(void) {}
> # define NMI_WATCHDOG_SYSCTL_PERM 0444
> #endif
>
> -#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
> +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) || \
> + defined(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET)
Why not instead make CONFIG_X86_HARDLOCKUP_DETECTOR_HPET select
CONFIG_HARDLOCKUP_DETECTOR_PERF? Keep the arch-specific details
in the arch-specific files and all that.
Thanx, Paul
> extern void arch_touch_nmi_watchdog(void);
> +#else
> +# if !defined(CONFIG_HAVE_NMI_WATCHDOG)
> +static inline void arch_touch_nmi_watchdog(void) {}
> +# endif
> +#endif
> +
> +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
> extern void hardlockup_detector_perf_stop(void);
> extern void hardlockup_detector_perf_restart(void);
> extern void hardlockup_detector_perf_disable(void);
> --
> 2.17.1
>
