linux-kernel - Re: [PATCH v1] cpuidle: Do not return from cpuidle_play

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Message-ID: <20241115174022.GF22801@noisy.programming.kicks-ass.net>
Date: Fri, 15 Nov 2024 18:40:22 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: "Rafael J. Wysocki" <rafael@...nel.org>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>,
	Linux PM <linux-pm@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	x86 Maintainers <x86@...nel.org>,
	Patryk Wlazlyn <patryk.wlazlyn@...ux.intel.com>,
	"Gautham R. Shenoy" <gautham.shenoy@....com>,
	Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>,
	Mario Limonciello <mario.limonciello@....com>
Subject: Re: [PATCH v1] cpuidle: Do not return from cpuidle_play_dead() on
 callback failures

On Fri, Nov 15, 2024 at 02:25:23PM +0100, Rafael J. Wysocki wrote:
> > I mean, something like:
> >
> >         if (drv->states[i].enter_dead && !drv->states[i].enter_dead(dev, i))
> >                 panic("Dead CPU walking...");
> >
> > is 'fun' but not very useful.
> 
> The panic would be hard to debug if it ever triggers I'm afraid and
> there is the fallback to HLT in the caller.

I was being facetious, removing the return value and simply calling them
all in reverse order is fine.