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From: Andrew Morton <akpm@linux-foundation.org>
To: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 7/8] padata: Flush the padata queues actively
Date: Thu, 29 Apr 2010 16:11:12 -0700	[thread overview]
Message-ID: <20100429161112.f4bb67a3.akpm@linux-foundation.org> (raw)
In-Reply-To: <20100429124426.GK5275@secunet.com>

On Thu, 29 Apr 2010 14:44:26 +0200
Steffen Klassert <steffen.klassert@secunet.com> wrote:

> +static void padata_flush_queues(struct parallel_data *pd)
> +{
> +	int cpu;
> +	struct padata_queue *queue;
> +
> +	for_each_cpu(cpu, pd->cpumask) {
> +		queue = per_cpu_ptr(pd->queue, cpu);
> +		flush_work(&queue->pwork);
> +	}
> +
> +	del_timer_sync(&pd->timer);
> +
> +	if (atomic_read(&pd->reorder_objects))
> +		padata_reorder(pd);

padata_reorder() can fail to do anything, if someone else is holding
pd->lock.  What happens then?


> +	for_each_cpu(cpu, pd->cpumask) {
> +		queue = per_cpu_ptr(pd->queue, cpu);
> +		flush_work(&queue->swork);
> +	}
> +	BUG_ON(atomic_read(&pd->refcnt) != 0);
> +}

Are we safe against cpu hot-unplug in this code?

  reply	other threads:[~2010-04-30 18:54 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-29 12:36 [PATCH 0/8] padata: fixes/cleanups Steffen Klassert
2010-04-29 12:37 ` [PATCH 1/8] padata: Dont scale the parallel objects with the cpus Steffen Klassert
2010-04-29 12:40 ` [PATCH 2/8] padata: cpu hotplug code should depend on CONFIG_HOTPLUG_CPU Steffen Klassert
2010-04-29 12:40 ` [PATCH 3/8] padata: Remove superfluous might_sleep Steffen Klassert
2010-04-29 12:41 ` [PATCH 4/8] padata: Initialize the padata queues only for the used cpus Steffen Klassert
2010-04-29 12:42 ` [PATCH 5/8] padata: Use get_online_cpus/put_online_cpus Steffen Klassert
2010-04-29 12:43 ` [PATCH 6/8] padata: Use a timer to handle the reorder queues Steffen Klassert
2010-04-29 23:06   ` Andrew Morton
2010-04-30 11:20     ` Steffen Klassert
2010-05-03  3:38       ` Herbert Xu
2010-04-29 12:44 ` [PATCH 7/8] padata: Flush the padata queues actively Steffen Klassert
2010-04-29 23:11   ` Andrew Morton [this message]
2010-04-30 11:24     ` Steffen Klassert
2010-04-29 12:45 ` [PATCH 8/8] padata: Add some code comments Steffen Klassert
2010-04-29 23:13 ` [PATCH 0/8] padata: fixes/cleanups Andrew Morton

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