Re: [PATCH 16/16] 64bit Resource: finally enable 64bit resource sizes

Vivek Goyal
2006-06-15T19:40:13Z

On Thu, Jun 15, 2006 at 01:47:43PM +0200, Geert Uytterhoeven wrote:
> On Thu, 15 Jun 2006, Vivek Goyal wrote:
> > On Wed, Jun 14, 2006 at 04:35:07PM -0700, Greg KH wrote:
> > > On Wed, Jun 14, 2006 at 02:20:06PM +0200, Geert Uytterhoeven wrote:
> > > > On Mon, 12 Jun 2006, Greg KH wrote:
> > > > > From: Greg Kroah-Hartman <gregkh@suse.de>
> > > > >
> > > > > Introduce the Kconfig entry and actually switch to a 64bit value, if
> > > > > wanted, for resource_size_t.
> > > >
> > > > > diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> > > > > index 805b81f..22dcaa5 100644
> > > > > --- a/arch/m68k/Kconfig
> > > > > +++ b/arch/m68k/Kconfig
> > > > > @@ -368,6 +368,13 @@ config 060_WRITETHROUGH
> > > > >
> > > > > source "mm/Kconfig"
> > > > >
> > > > > +config RESOURCES_32BIT
> > > > > + bool "32 bit Memory and IO resources (EXPERIMENTAL)"
> > > > > + depends on EXPERIMENTAL
> > > > > + help
> > > > > + By default resources are 64 bit. This option allows memory and IO
> > > > > + resources to be 32 bit to optimize code size.
> > > > > +
> > > > > endmenu
> > > >
> > > > Why is the default 64 bit? Because 32 bit became experimental?
> > >
> > > That's a really good question. Vivek, why did you change it to be this
> > > way? In thinking about it some more, this should be a 64bit option
> > > instead.
> > >
> >
> > I thought 64bit is more inclusive. Works both for 32bit and 64bit BARs.
>
> >From a PCI viewpoint? Not all machines have PCI.
>
> > Also exports memory more than 4G through /proc/iomem without selecting
> > an additional option in config file. The flip side is that it introduces
> > little memory overhead. I thought most of the users should be ok with this
> > increased memory usage and those who are particular, they can choose
> > RESOURCES_32BIT.
>
> Not all 32 bit platforms support more than 4 GiB of memory, so it's of no use
> to waste memory on 64 bit resources.
>

Hmm.. That makes sense. I will rework the patch.

Thanks
Vivek