Re: [PATCH 32/38] arm64: nmi: Add Kconfig for NMI

On 9/16/26 10:06, Jinjie Ruan wrote:

在 2026/9/14 18:20, Vladimir Murzin 写道:

quoted

From: Mark Brown <broonie@kernel.org>

Since NMI handling is in some fairly hot paths we provide a Kconfig
option which allows support to be compiled out when not needed.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Ada Couprie Diaz <redacted>
Signed-off-by: Vladimir Murzin <redacted>
---
 arch/arm64/Kconfig | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2738637ccb92..df5ff59715d1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig

@@ -2251,6 +2251,24 @@ endmenu # "ARMv8.7 architectural features"
 config AS_HAS_MOPS
 	def_bool $(as-instr,.arch_extension mops)
 
+menu "ARMv8.8 architectural features"
+
+config ARM64_NMI
+	bool "Enable support for Non-maskable Interrupts (NMI)"
+	default y

We should select HAVE_PERF_EVENTS_NMI to enable perf-NMI-based
hardlockup detector as pseudo NMI do.

It seems there are ongoing discussions [1,2] about moving away from it
towards the buddy detector. So I can add it, but I'm not sure whether
it will still be necessary in the future.

[1] https://lore.kernel.org/linux-arm-kernel/amtyQH7lzLDKE3WD@thinkstation/ (local)
[2] https://lore.kernel.org/lkml/20260902-qcom-wdt-nmi-series-v3-0-f3999362a9ea@google.com/ (local)

Thanks
Vladimir

arch/arm64/Kconfig:     select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
|| ARM64_NMI

quoted

+	help
+	  Non-maskable interrupts are an architecture and GIC feature
+	  which allow the system to configure some interrupts to be
+	  configured to have superpriority, allowing them to be handled
+	  before other interrupts and masked for shorter periods of time.
+
+	  The feature is detected at runtime, and will remain disabled
+	  if the cpu does not implement the feature. It will also be
+	  disabled if pseudo NMIs are enabled at runtime.
+
+endmenu # "ARMv8.8 architectural features"
+
+
 menu "ARMv8.9 architectural features"
 
 config ARM64_POE