Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock

H.J. Lu
2010-07-14T19:40:10Z

On Wed, Jul 14, 2010 at 12:36 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 07/14/2010 12:32 PM, H.J. Lu wrote:
>> On Wed, Jul 14, 2010 at 12:00 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>>> On 07/14/2010 11:18 AM, H.J. Lu wrote:
>>>>
>>>> There are some discussions on:
>>>>
>>>> http://gcc.gnu.org/ml/gcc-patches/2010-06/msg02001.html
>>>> http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00001.html
>>>>
>>>> Are they related?
>>>>
>>>
>>> Not directly as far as I can tell.
>>>
>>> The issue is if gcc can ever reorder, duplicate or elide a volatile
>>> operation (either asm volatile or a volatile-annotated memory
>>> reference.)  In my (and Linus') opinion, this would be an incredibly
>>> serious bug.
>>
>> Is there a gcc bug for this?
>>
>
> Are you asking for a bug report against the documentation?  We're not
> sure what the semantics intended by the gcc team to be, which I guess is
> a documentation bug.
>

Documentation bug is also a bug :-).

--
H.J.