On Tue, 2021-11-16 at 09:41 +0100, Petr Mladek wrote: [...] > If I wanted to implement a super-reliable panic() I would > use some external device that would cause power-reset when > the watched device is not responding. They're called watchdog timers. We have a whole subsystem full of them: drivers/watchdog We used them in old cluster HA systems to guarantee successful recovery of shared state from contaminated cluster members, but I think they'd serve the reliable panic need equally well. Most server class systems today have them built in (on the BMC if they don't have a separate mechanism), they're just not usually activated. James