[PATCH] watchdog: remove HARDLOCKUP_DETECTOR_PERF

[Peter Zijlstra]

On Mon, Sep 15, 2025 at 11:26:09AM +0100, Will Deacon wrote:

>   | If all CPUs are hard locked up at the same time the buddy system
>   | can't detect it.
> 
> Ok, so why is that limitation acceptable? It looks to me like you're
> removing useful functionality.

Yeah, this. I've run into this case waaay too many times to think it
reasonable to remove the perf/NMI based lockup detector.