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From: Tejun Heo <tj@kernel.org>
To: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: linux-kernel@vger.kernel.org,
	Lai Jiangshan <laijs@linux.alibaba.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 04/10] workqueue: don't set the worker's cpumask when kthread_bind_mask()
Date: Wed, 16 Dec 2020 09:39:06 -0500	[thread overview]
Message-ID: <X9ocCpJC87d2vjdg@mtj.duckdns.org> (raw)
In-Reply-To: <20201214155457.3430-5-jiangshanlai@gmail.com>

On Mon, Dec 14, 2020 at 11:54:51PM +0800, Lai Jiangshan wrote:
> @@ -1945,7 +1945,15 @@ static struct worker *create_worker(struct worker_pool *pool)
>  		goto fail;
>  
>  	set_user_nice(worker->task, pool->attrs->nice);
> -	kthread_bind_mask(worker->task, pool->attrs->cpumask);
> +
> +	/*
> +	 * Set PF_NO_SETAFFINITY via kthread_bind_mask().  We use
> +	 * cpu_possible_mask other than pool->attrs->cpumask, because
                             ^
                             instead of

> +	 * there might be no online cpu in the pool->attrs->cpumask.
                 ^
                 might not be any

> +	 * The cpumask of the worker will be set properly later in
> +	 * worker_attach_to_pool().
> +	 */
> +	kthread_bind_mask(worker->task, cpu_possible_mask);

This is a bit ugly but not the end of the world. Maybe we can move it to the
start of worker_thread() but that'd require an extra handshake. Oh well...

Thanks.

-- 
tejun

  reply	other threads:[~2020-12-16 14:40 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-14 15:54 [PATCH 00/10] workqueue: break affinity initiatively Lai Jiangshan
2020-12-14 15:54 ` [PATCH 01/10] workqueue: restore unbound_workers' cpumask correctly Lai Jiangshan
2020-12-14 15:54 ` [PATCH 02/10] workqueue: use cpu_possible_mask instead of cpu_active_mask to break affinity Lai Jiangshan
2020-12-14 17:25   ` Peter Zijlstra
2020-12-15  8:33     ` Lai Jiangshan
2020-12-15  8:40     ` Peter Zijlstra
2020-12-16 14:32   ` Tejun Heo
2020-12-14 15:54 ` [PATCH 03/10] workqueue: Manually break affinity on pool detachment Lai Jiangshan
2020-12-14 15:54 ` [PATCH 04/10] workqueue: don't set the worker's cpumask when kthread_bind_mask() Lai Jiangshan
2020-12-16 14:39   ` Tejun Heo [this message]
2020-12-14 15:54 ` [PATCH 05/10] workqueue: introduce wq_online_cpumask Lai Jiangshan
2020-12-14 15:54 ` [PATCH 06/10] workqueue: use wq_online_cpumask in restore_unbound_workers_cpumask() Lai Jiangshan
2020-12-14 15:54 ` [PATCH 07/10] workqueue: Manually break affinity on hotplug for unbound pool Lai Jiangshan
2020-12-16 14:50   ` Tejun Heo
2020-12-14 15:54 ` [PATCH 08/10] workqueue: reorganize workqueue_online_cpu() Lai Jiangshan
2020-12-14 15:54 ` [PATCH 09/10] workqueue: reorganize workqueue_offline_cpu() unbind_workers() Lai Jiangshan
2020-12-14 15:54 ` [PATCH 10/10] workqueue: Fix affinity of kworkers when attaching into pool Lai Jiangshan
2020-12-15 15:03   ` Valentin Schneider
2020-12-14 17:36 ` [PATCH 00/10] workqueue: break affinity initiatively Peter Zijlstra
2020-12-15  5:44   ` Lai Jiangshan
2020-12-15  7:50     ` Peter Zijlstra
2020-12-15  8:14       ` Lai Jiangshan
2020-12-15  8:49         ` Peter Zijlstra
2020-12-15  9:46           ` Lai Jiangshan
2020-12-16 14:30 ` Tejun Heo

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