Re: [Xen-devel] Re: [patch 21/26] Xen-paravirt_ops: Use the hvc console infrastructure for Xen console

Keir Fraser
2007-03-16T11:58:33Z

On 16/3/07 11:41, "Andrew Morton" <akpm@linux-foundation.org> wrote:

>> It's needed for writing data /after/ reading the consumer index that shows
>> you have space to write. Looking through xenbus_comms.c I think all the
>> barriers are correct except there is a spurious extra mb() in xb_read(),
>> where there is a later rmb() which is sufficient by itself. All the others
>> have a purpose.
>>
>
> If Ingo couldn't work this out from reading the code then nobody else can,
> and we have a maintainability problem which can only be solved with
> adequate commenting.

Agreed. I've fixed up the commenting, removed the spurious mb(), and I just
need Jeremy to merge that change into the Xen pv_ops patchset. :-)

-- Keir