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From: Tejun Heo <tj@kernel.org>
To: Breno Leitao <leitao@debian.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-kernel@vger.kernel.org, kernel-team@meta.com
Subject: Re: [PATCH] workqueue: read p->wake_cpu once in kick_pool_pick()
Date: Mon, 10 Aug 2026 09:50:57 -1000	[thread overview]
Message-ID: <anoroQ1IxX94STnH@slm.duckdns.org> (raw)
In-Reply-To: <20260805-wq_race_kick-v1-1-d55adc12416b@debian.org>

On Wed, Aug 05, 2026 at 04:17:48AM -0700, Breno Leitao wrote:
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 26d5680c751c6..333752ac38298 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -1308,8 +1308,10 @@ static bool kick_pool_pick(struct worker_pool *pool, struct task_struct **wakep)
>  	 * If @pool has non-strict affinity, @worker might have ended up outside
>  	 * its affinity scope. Repatriate.
>  	 */
> -	if (!pool->attrs->affn_strict &&
> -	    !cpumask_test_cpu(p->wake_cpu, pool->attrs->__pod_cpumask)) {
> +	bool wake_cpu_in_pod = cpumask_test_cpu(READ_ONCE(p->wake_cpu),
> +						pool->attrs->__pod_cpumask);
> +
> +	if (!pool->attrs->affn_strict && !wake_cpu_in_pod) {

Can you update the p->wake_cpu assignement several lines below to
WRITE_ONCE() too?

Thanks.

-- 
tejun

  parent reply	other threads:[~2026-08-10 19:50 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-05 11:17 [PATCH] workqueue: read p->wake_cpu once in kick_pool_pick() Breno Leitao
2026-08-05 18:42 ` Bradley Morgan
2026-08-10 19:50 ` Tejun Heo [this message]
2026-08-11  9:28   ` Breno Leitao

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