This repository was archived by the owner on Jul 16, 2024. It is now read-only.
This repository was archived by the owner on Jul 16, 2024. It is now read-only.
support all_cpu_backtrace #178
Description
In doc: https://www.kernel.org/doc/Documentation/admin-guide/sysctl/kernel.rst
hardlockup_all_cpu_backtrace
============================
This value controls the hard lockup detector behavior when a hard
lockup condition is detected as to whether or not to gather further
debug information. If enabled, arch-specific all-CPU stack dumping
will be initiated.
= ============================================
0 Do nothing. This is the default behavior.
1 On detection capture more debug information.
= ============================================
hung_task_all_cpu_backtrace
===========================
If this option is set, the kernel will send an NMI to all CPUs to dump
their backtraces when a hung task is detected. This file shows up if
CONFIG_DETECT_HUNG_TASK and CONFIG_SMP are enabled.
0: Won't show all CPUs backtraces when a hung task is detected.
This is the default behavior.
1: Will non-maskably interrupt all CPUs and dump their backtraces when
a hung task is detected.
oops_all_cpu_backtrace
======================
If this option is set, the kernel will send an NMI to all CPUs to dump
their backtraces when an oops event occurs. It should be used as a last
resort in case a panic cannot be triggered (to protect VMs running, for
example) or kdump can't be collected. This file shows up if CONFIG_SMP
is enabled.
0: Won't show all CPUs backtraces when an oops is detected.
This is the default behavior.
1: Will non-maskably interrupt all CPUs and dump their backtraces when
an oops event is detected.
softlockup_all_cpu_backtrace
============================
This value controls the soft lockup detector thread's behavior
when a soft lockup condition is detected as to whether or not
to gather further debug information. If enabled, each cpu will
be issued an NMI and instructed to capture stack trace.
This feature is only applicable for architectures which support
NMI.
= ============================================
0 Do nothing. This is the default behavior.
1 On detection capture more debug information.
= ============================================
We might need to apply the NMI IPI patches to make this happen:
https://patchwork.kernel.org/project/linux-arm-kernel/cover/20190506082542.11357-1-liwei391@huawei.com/ : [0/3] arm64: Add support for on-demand backtrace by NMI-like IPI
https://lore.kernel.org/linux-arm-kernel/CAFA6WYO0+LQ=mB1spCstt0cNZ0G+sZu_+Wrv6BKSeXqF5SRq4A@mail.gmail.com/T/
arm64: Add framework to turn an IPI as NMI
Check, backport these patches and test. Target for 5.15 kernel firstly.