linux-kernel - Re: [PATCH] watchdog: remove HARDLOCKUP_DETECTOR

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Message-ID: <20250915103506.GA3245006@noisy.programming.kicks-ass.net>
Date: Mon, 15 Sep 2025 12:35:06 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Will Deacon <will@...nel.org>
Cc: Yunhui Cui <cuiyunhui@...edance.com>, akpm@...ux-foundation.org,
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Subject: Re: [PATCH] watchdog: remove HARDLOCKUP_DETECTOR_PERF

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.