linux-kernel - Re: [PATCH 1/5] Add a global synchronization point for pvclock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4BCC3584.1050501@redhat.com>
Date:	Mon, 19 Apr 2010 13:50:44 +0300
From:	Avi Kivity <avi@...hat.com>
To:	Peter Zijlstra <peterz@...radead.org>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>,
	Glauber Costa <glommer@...hat.com>, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Zachary Amsden <zamsden@...hat.com>
Subject: Re: [PATCH 1/5] Add a global synchronization point for pvclock

On 04/19/2010 01:39 PM, Peter Zijlstra wrote:
> On Fri, 2010-04-16 at 13:36 -0700, Jeremy Fitzhardinge wrote:
>    
>>> +     do {
>>> +             last = last_value;
>>>
>>>        
>> Does this need a barrier() to prevent the compiler from re-reading
>> last_value for the subsequent lines?  Otherwise "(ret<  last)" and
>> "return last" could execute with different values for "last".
>>
>>      
> ACCESS_ONCE() is your friend.
>    

I think it's implied with atomic64_read().

-- 
error compiling committee.c: too many arguments to function

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/