Re: [Qemu-devel] [PULL 00/22] Docker and block patches

[Fam Zheng]

On Tue, 05/30 11:36, Paolo Bonzini wrote:
> 
> 
> On 30/05/2017 11:33, Fam Zheng wrote:
> > On Tue, 05/30 10:19, Stefan Hajnoczi wrote:
> >> On Fri, May 26, 2017 at 03:52:24PM +0800, Fam Zheng wrote:
> >>> The following changes since commit 
> >>> 9964e96dc9999cf7f7c936ee854a795415d19b60:
> >>>
> >>>   Merge remote-tracking branch 'jasowang/tags/net-pull-request' into 
> >>> staging (2017-05-23 15:01:31 +0100)
> >>>
> >>> are available in the git repository at:
> >>>
> >>>   git://github.com/famz/qemu.git tags/docker-and-block-pull-request
> >>>
> >>> for you to fetch changes up to 77269bba94ef97de99ae61fdc98629a8704ae2ed:
> >>>
> >>>   block: make accounting thread-safe (2017-05-26 09:25:30 +0800)
> >>>
> >>> ----------------------------------------------------------------
> >>>
> >>> For Paolo's block layer thread safety part I and my docker testing
> >>> enhancements.
> >>
> >> Please fix the checkpatch issues.
> > 
> > Paolo, could you provide the comments that can be added to the memory 
> > barriers?
> 
> It's a false positive.  The comments are just a couple lines above:
> 
>         /* We have to set low before high, just like stat64_max reads
>          * high before low.  The value may become lower temporarily, but
>          * stat64_get does not notice (it takes the lock) and the only ill
>          * effect on stat64_max is that the slow path may be triggered
>          * unnecessarily.
>          */
>         atomic_set(&s->low, (uint32_t)value);
>         smp_wmb();
>         atomic_set(&s->high, value >> 32);

Ah okay, thanks!

Fam