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

H. Peter Anvin
2010-07-14T19:37:27Z

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.

-hpa