[PATCH v4 13/17] watchdog/hardlockup: detect hard lockups using secondary (buddy) CPUs

Nicholas Piggin npiggin at gmail.com
Fri May 5 12:35:39 AEST 2023

On Fri May 5, 2023 at 8:13 AM AEST, Douglas Anderson wrote:
> From: Colin Cross <ccross at android.com>
> Implement a hardlockup detector that doesn't doesn't need any extra
> arch-specific support code to detect lockups. Instead of using
> something arch-specific we will use the buddy system, where each CPU
> watches out for another one. Specifically, each CPU will use its
> softlockup hrtimer to check that the next CPU is processing hrtimer
> interrupts by verifying that a counter is increasing.

Powerpc's watchdog has an SMP checker, did you see it? It's all to
all rather than buddy which makes it more complicated but arguably
bit better functionality.


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