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" <h...@zytor.com>
> Cc: Ashok Raj <ashok....@intel.com>
> Cc: Andi Kleen <andi.kl...@intel.com>
> Cc: Tony Luck <tony.l...@intel.com>
> Cc: "Rafael J. Wysocki" <rafael.j.wyso...@intel.com>
> Cc: Don Zickus <dzic...@redhat.com>
> Cc: Nicholas Piggin <npig...@gmail.com>
> Cc: Michael Ellerman <m...@ellerman.id.au>
> Cc: Frederic Weisbecker <frede...@kernel.org>
> Cc: Alexei Starovoitov <a...@kernel.org>
> Cc: Babu Moger <babu.mo...@oracle.com>
> Cc: "David S. Miller" <da...@davemloft.net>
> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
> Cc: Paul Mackerras <pau...@samba.org>
> Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> Cc: Masami Hiramatsu <mhira...@kernel.org>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Philippe Ombredanne <pombreda...@nexb.com>
> Cc: Colin Ian King <colin.k...@canonical.com>
> Cc: Byungchul Park <byungchul.p...@lge.com>
> Cc: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
> Cc: "Luis R. Rodriguez" <mcg...@kernel.org>
> Cc: Waiman Long <long...@redhat.com>
> Cc: Josh Poimboeuf <jpoim...@redhat.com>
> Cc: Randy Dunlap <rdun...@infradead.org>
> Cc: Davidlohr Bueso <d...@stgolabs.net>
> Cc: Christoffer Dall <cd...@linaro.org>
> Cc: Marc Zyngier <marc.zyng...@arm.com>
> Cc: Kai-Heng Feng <kai.heng.f...@canonical.com>
> Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
> Cc: David Rientjes <rient...@google.com>
> Cc: "Ravi V. Shankar" <ravi.v.shan...@intel.com>
> Cc: x...@kernel.org
> Cc: sparcli...@vger.kernel.org
> Cc: linuxppc-...@lists.ozlabs.org
> Signed-off-by: Ricardo Neri <ricardo.neri-calde...@linux.intel.com>
> ---
> 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
>
