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AmpereComputing / ampere-lts-kernel---DEPRECATED

Linux 5.4 and 5.10 Longterm kernel (LTS) with Ampere patches
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perf-nmi causes kernel hang on 5.10.27 kernel #62

Open adamliyi opened 3 years ago

adamliyi commented 3 years ago

Kernel: 5.10.27 Refer to: https://github.com/AmpereComputing/ampere-lts-kernel/wiki/perf-pmu-and-more#pmu-non-maskable-interrupt-nmi

When enable perf-nmi:

  1. enable 'CONFIG_ARM64_PSEUDO_NMI'
  2. set 'irqchip.gicv3_pseudo_nmi=1' in kernel command line. When kernel boots, dmesg shows:

Observed kernel hang (rcu stall) when kernel boot.

adamliyi commented 3 years ago

It looks we need another patchset to enable pmu-nmi: https://lore.kernel.org/linux-arm-kernel/20210608172715.2396787-1-maz@kernel.org/ (arm64: Fix cpuidle with pseudo-NMI enabled). The patch set is in 5.14 kernel.

adamliyi commented 3 years ago

Fixed by PR: https://github.com/AmpereComputing/ampere-lts-kernel/pull/64 (5.10 backport) and https://github.com/AmpereComputing/ampere-lts-kernel/pull/65 (5.14 backport)