From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 09/18] fs: rework icount to be a locked variable
Date: Fri, 8 Oct 2010 10:17:14 +0200
Message-ID: <20101008081714.GB1728@lst.de>
References: <1286515292-15882-1-git-send-email-david@fromorbit.com> <1286515292-15882-10-git-send-email-david@fromorbit.com> <20101008072749.GB7831@lst.de> <20101008075001.GT4681@dastard>
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Cc: Christoph Hellwig <hch@lst.de>, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, chris.mason@oracle.com,
	linux-btrfs@vger.kernel.org
To: Dave Chinner <david@fromorbit.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20101008075001.GT4681@dastard>
List-ID: <linux-btrfs.vger.kernel.org>

On Fri, Oct 08, 2010 at 06:50:01PM +1100, Dave Chinner wrote:
> > There's no need to lock a normal 32-bit variable for readers.
> 
> Ok, but will need a memory barrier instead?

Isn't spin_unlock supposed to be one?  I'll need some of the locking
experts to shime in.