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From: Tim Gardner <rtg.canonical@gmail.com>
To: Asias He <asias@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	tim.gardner@canonical.com
Subject: Re: [PATCH V3] block: Mitigate lock unbalance caused by lock switching
Date: Tue, 29 May 2012 07:45:22 -0600	[thread overview]
Message-ID: <4FC4D2F2.2070309@gmail.com> (raw)
In-Reply-To: <1338255542-22247-1-git-send-email-asias@redhat.com>

On 05/28/2012 07:39 PM, Asias He wrote:

<snip>

> @@ -440,6 +435,11 @@ void blk_cleanup_queue(struct request_queue *q)
>  	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
>  	blk_sync_queue(q);
>  
> +	spin_lock_irq(lock);
> +	if (q->queue_lock != &q->__queue_lock)
> +		q->queue_lock = &q->__queue_lock;
> +	spin_unlock_irq(lock);
> +

Isn't the 'if' clause superfluous ? You could just do the assignment, e.g.,

+	spin_lock_irq(lock);
+	q->queue_lock = &q->__queue_lock;
+	spin_unlock_irq(lock);

rtg
-- 
Tim Gardner tim.gardner@canonical.com

  parent reply	other threads:[~2012-05-29 13:46 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-25  2:10 [PATCH] block: Fix lock unbalance caused by lock disconnect Asias He
2012-05-28  0:07 ` Tejun Heo
2012-05-28  2:15   ` Asias He
2012-05-28 10:20     ` Tejun Heo
2012-05-29  1:49       ` Asias He
2012-06-01  9:28       ` Michael S. Tsirkin
2012-05-28  2:20   ` [PATCH v2] block: Mitigate " Asias He
2012-05-28 10:22     ` Tejun Heo
2012-05-29  1:39       ` [PATCH V3] block: Mitigate lock unbalance caused by lock switching Asias He
2012-05-29  1:39         ` [PATCH] " Asias He
2012-05-29  1:41         ` [PATCH V3] " Tejun Heo
2012-05-29 13:45         ` Tim Gardner [this message]
2012-05-30  6:28           ` Asias He
2012-05-30  6:28             ` Tejun Heo
2012-05-30  6:50               ` Asias He
2012-06-01  9:31               ` Jens Axboe
2012-06-06  2:12                 ` Asias He

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