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Date: Thu, 21 May 2015 19:34:20 +0000 (UTC)
From: Keith Busch <keith.busch@intel.com>
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To: Parav Pandit <parav.pandit@avagotech.com>
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        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] NVMe: Avoid interrupt disable during queue init.
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On Thu, 21 May 2015, Parav Pandit wrote:
> Avoid diabling interrupt and holding q_lock for the queue
> which is just getting initialized.
>
> With this change, online_queues is also incremented without
> lock during queue setup stage.
> if Power management nvme_suspend() kicks in during queue setup time,
> per nvmeq based q_lock spinlock cannot protect device wide
> online_queues variable anyway.

The q_lock is held to protect polling from reading inconsistent data.