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

Geert Uytterhoeven
2006-06-15T11:48:18Z

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.

I'd prefer to have an option to explicitly enable 64 bit resources (and make 32
bit resources non-experimental ;-).

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds