From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Slaby <jirislaby@gmail.com>
Subject: Re: [RFC 09/15] PM / Hibernate: user,
	implement user_ops writer
Date: Wed, 24 Mar 2010 22:40:56 +0100
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To: Pavel Machek <pavel@ucw.cz>
Cc: linux-pm@lists.linux-foundation.org, Nigel Cunningham <ncunningham@crca.org.au>, linux-kernel@vger.kernel.org
List-Id: linux-pm@vger.kernel.org

On 03/24/2010 09:42 PM, Pavel Machek wrote:
>> +	if (test_bit(TODO_CLOSED, to_do_flags))
>> +		return -EIO;
>> +
>> +	to_do_buf = buf;
>> +	wmb();
>> +	set_bit(TODO_WORK, to_do_flags);
>> +	wake_up_interruptible(&to_do_wait);
> 
> Uhuh, open-coded barriers... these need to be commented, and I guess
> you just should not play this kind of trickery.

It's just to ensure the to_do_buf store is not reordered with the
set_bit. I wanted to avoid locks as too heavy tools here.

thanks,
-- 
js