Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 26 May 2022 09:24:28 +0100
From:   Vincent Donnefort <vdonnefort@google.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     tglx@linutronix.de, linux-kernel@vger.kernel.org,
        vschneid@redhat.com, kernel-team@android.com,
        Derek Dolney <z23@posteo.net>
Subject: Re: [PATCH v2] cpu/hotplug: Do not bail-out in DYING/STARTING
 sections
Message-ID: <Yo85PLANCnCcMgvD@google.com>
References: <20220523160536.2889162-1-vdonnefort@google.com>
 <20220525165248.GI2578@worktop.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220525165248.GI2578@worktop.programming.kicks-ass.net>
Precedence: bulk

On Wed, May 25, 2022 at 06:52:48PM +0200, Peter Zijlstra wrote:
> On Mon, May 23, 2022 at 05:05:36PM +0100, Vincent Donnefort wrote:
> > The DYING/STARTING callbacks are not expected to fail. However, as reported
> > by Derek, drivers such as tboot are still free to return errors within
> > those sections. In that case, there's nothing the hotplug machinery can do,
> > so let's just proceed and log the failures.
> > 
> 
> I'm confused. Why isn't this a driver bug?

It is a entirely a driver bug which has been reported already. but 453e41085183
(cpu/hotplug: Add cpuhp_invoke_callback_range()) changed the behaviour so I
thought it would be worth to revert to the original one which is to not break
the entire up/down for a single driver error.