Re: [PATCH] arm64: Only HAVE_HARDLOCKUP_DETECTOR_PERF if the PMU config is enabled

[Arnd Bergmann]

On Tue, May 23, 2023, at 16:39, Douglas Anderson wrote:
> If you try to enable the arm64 perf-based hardlockup detector but you
> don't enable CONFIG_ARM_PMU then you'll get an error:
>
> arch/arm64/kernel/watchdog_hld.c: In function 
> 'arch_perf_nmi_is_available':
> arch/arm64/kernel/watchdog_hld.c:35:16: error: implicit declaration of 
> function 'arm_pmu_irq_is_nmi' [-Werror=implicit-function-declaration]
>    35 |         return arm_pmu_irq_is_nmi();
>
> It doesn't make sense to enable HAVE_HARDLOCKUP_DETECTOR_PERF if the
> PMU isn't enabled. Let's add a dependency. HW_PERF_EVENTS is a synonum
> for ARM_PMU and makes the most logical sense here, so add the
> dependency on that.
>
> Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
> Closes: https://lore.kernel.org/r/20230522114922.1052421-1-arnd@xxxxxxxxxx
> Fixes: 02ea35ee19d9 ("arm64: enable perf events based hard lockup detector")
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>

Still build testing it with randconfigs, but I assume it's fine.

    Arnd