Re: [Xen-ia64-devel] [PATCH 1/7][SMP] add volatile to mpt_table

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

On Fri, Jun 16, 2006 at 04:48:57PM +0200, Tristan Gingold wrote:
> Le Vendredi 16 Juin 2006 16:32, Alex Williamson a écrit :
> > On Fri, 2006-06-16 at 10:38 +0900, Isaku Yamahata wrote:
> > > The below two lines follows.
> > >
> > >         map_start = mpt_table + (__pa(start) >> PAGE_SHIFT);
> > >         map_end   = mpt_table + (__pa(end) >> PAGE_SHIFT);
> > >
> > > Gcc produces warnings without volatile.
> >
> > Isaku,
> >
> >    I think it would be more clear to cast mpt_table as a non-volatile
> > than to introduce new volatile variables to avoid compiler warnings.
> > These has me confused as well.  Thanks,
> Just my opinion:
> 
> I don't see the confusion and I don't like the cast.  I'd prefer to keep the 
> qualifier.
> If map_start/map_end are not deferred the volatile qualifier has no cost.  If
> they are deferred, the volatile qualifier should be kept.
> 
> [Again, this is just my opinion].

create_mpttable_page_table() does the cast anyway.
I hope the attached patch is better for everyone.

-- 
yamahata

Attachment: 10420:cb80c9b07210_volatile_mpt_table.patch
Description: Text document

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