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From: Peter Zijlstra <peterz@infradead.org>
To: vincent.donnefort@arm.com
Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org,
	valentin.schneider@arm.com
Subject: Re: [PATCH 3/4] cpu/hotplug: Add cpuhp_invoke_callback_range()
Date: Wed, 20 Jan 2021 18:53:33 +0100	[thread overview]
Message-ID: <YAhuHdcfKnyWKdka@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <YAhsLPLXg37fs/BA@hirez.programming.kicks-ass.net>

On Wed, Jan 20, 2021 at 06:45:16PM +0100, Peter Zijlstra wrote:
> On Mon, Jan 11, 2021 at 05:10:46PM +0000, vincent.donnefort@arm.com wrote:
> > @@ -475,6 +478,11 @@ cpuhp_set_state(struct cpuhp_cpu_state *st, enum cpuhp_state target)
> >  static inline void
> >  cpuhp_reset_state(struct cpuhp_cpu_state *st, enum cpuhp_state prev_state)
> >  {
> > +	st->target = prev_state;
> > +
> > +	if (st->rollback)
> > +		return;
> 
> I'm thinking that if we call rollback while already rollback we're hosed
> something fierce, no?
> 
> That like going up, failing, going back down again, also failing, giving
> up in a fiery death.

Ooh, is this a hack for _cpu_down():

	ret = cpuhp_down_callbacks(cpu, st, target);
	if (ret && st->state == CPUHP_TEARDOWN_CPU && st->state < prev_state) {
		cpuhp_reset_state(st, prev_state);
		__cpuhp_kick_ap(st);
	}

Where cpuhp_down_callbacks() can already have called cpuhp_reset_state() ?

  reply	other threads:[~2021-01-20 18:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-11 17:10 [PATCH 0/4] cpu/hotplug: rollback and "fail" interface fixes vincent.donnefort
2021-01-11 17:10 ` [PATCH 1/4] cpu/hotplug: Allowing to reset fail injection vincent.donnefort
2021-01-11 17:10 ` [PATCH 2/4] cpu/hotplug: CPUHP_BRINGUP_CPU exception in " vincent.donnefort
2021-01-20 12:58   ` Peter Zijlstra
2021-01-20 15:17     ` Vincent Donnefort
2021-01-20 17:30       ` Peter Zijlstra
2021-01-11 17:10 ` [PATCH 3/4] cpu/hotplug: Add cpuhp_invoke_callback_range() vincent.donnefort
2021-01-20 13:11   ` Peter Zijlstra
2021-01-20 17:54     ` Peter Zijlstra
2021-01-20 17:45   ` Peter Zijlstra
2021-01-20 17:53     ` Peter Zijlstra [this message]
2021-01-21 10:57       ` Vincent Donnefort
2021-01-21 11:18         ` Peter Zijlstra
2021-01-20 17:49   ` Peter Zijlstra
2021-01-11 17:10 ` [PATCH 4/4] cpu/hotplug: Fix CPU down rollback vincent.donnefort
2021-01-21 14:57   ` Peter Zijlstra
2021-01-21 15:43     ` Vincent Donnefort

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