Re: 2GB address space limit on 32-bit PowerPC Macintosh

[Kumar Gala <kumar.gala@freescale.com>]

On May 16, 2005, at 12:52 AM, Benjamin Herrenschmidt wrote:

>
>
> > >
>  > > We need to fix that too :) Though I suppose we can just switch=20
> that to
>  > >=A0 page tables, I don't really see the point of using a BAT =
here...
>  >
> > Are the embedded board ports broken because of similar
> > io_block_mapping() calls or for some other reason?
>  =A0
>  Mostly because of the above, though some embedded ports may do even=20=

> more
>  horrible things for what i know :) The problem with =
io_block_mapping()
> is that 1) it lets you put those BARs or mappings where you want, and=20=

> 2)
>  you end up with plenty of code hard-coding this virtual address here=20=

> or
>  there that need to be fixed.

I'm interested to see if Paul is aware of any other embedded port=20
issues, since he mentioned the problem there.

Agreed, the other problem that comes up from time to time due to=20
io_block_mapping() that I've see is problem with modules not working=20
because the kernel doesn't think it has any vmalloc() space left.

> > I'm in agreement that we should bump TASK_SIZE to 3GB and fix =
things,
> > how about after 2.6.12 is out?
>
> Agreed. I'll fix PReP/CHRP/pmac & defconfig. Every embedded board
>  vendor/maintainer will be responsible for fixing his/her boards=20
> support.

Agreed.  We should probably send an email to linuxppc-embedded with a=20
more proper subject line to let people know.

- kumar