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Date: Mon, 3 Nov 2025 14:10:51 +0100
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH] cpu: Make atomic callbacks run on UP with disabled
 interrupts
Message-ID: <20251103131051._qx__Noh@linutronix.de>
References: <20251103120354.HU-oB1_z@linutronix.de>
 <20251103124254.GA3245006@noisy.programming.kicks-ass.net>
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In-Reply-To: <20251103124254.GA3245006@noisy.programming.kicks-ass.net>

On 2025-11-03 13:42:54 [+0100], Peter Zijlstra wrote:
> How about:
> 
> 	if (cpuhp_is_atomic_state(state)) {
> 		guard(irqsave)();
> 		ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
> 		/*
> 		 * STARTING/DYING must not fail!
> 		 */
> 		WARN_ON_ONCE(ret);
> 	} else {
> 		ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL);
> 	}
> 
> which is a little more like cpuhp_thread_fun()

very nice indeed. What about WARN_ON_ONCE(ret && bringup) given the
BUG_ON(ret && !bringup) below?

> 

Sebastian