Re: Discontiguous memory fun

Re: Discontiguous memory fun

[Jon Masters]

Replying to my own post...

On 9/1/05, Jon Masters <jonmasters@gmail.com> wrote:

>  I've got a hardware platform based on an ARM922, a bit like Excalibur,
> which has a nice large hole in memory:
>
>  0x0000_0000 - 32MB (or whatever) of SDRAM.
>  0x8000_0000 - 64MB (or whatever) of SDRAM.

I fixed it using a bodge similar to PHYS_OFFSET and disabled the lower
bank of memory if the kernel was booted at the higher address since it
was extremely difficult to play with the half-support for discontig in
old 2.4 ARM kernels (all of the existing boards are just playing a
game of luck with their memory/node mappings) without a working BDI.

I'd love to know what the state of discontig memory is like on 2.6
series ARM kernels and highmem too for that matter, but I've not had
chance to look at it (I'm usually a ppc guy).

Jon.

Re: Discontiguous memory fun

[Marc Singer]

On Sun, Oct 02, 2005 at 07:57:30PM +0100, Jon Masters wrote:
> Replying to my own post...
> 
> On 9/1/05, Jon Masters <jonmasters@gmail.com> wrote:
> 
> I'd love to know what the state of discontig memory is like on 2.6
> series ARM kernels and highmem too for that matter, but I've not had
> chance to look at it (I'm usually a ppc guy).

It works fine.

The node mapping is performed by macros in asm-arm/arch-*/memory.h.

Re: Discontiguous memory fun

[Jon Masters]

On 10/3/05, Marc Singer <elf@buici.com> wrote:

> On Sun, Oct 02, 2005 at 07:57:30PM +0100, Jon Masters wrote:
> > Replying to my own post...
> >
> > On 9/1/05, Jon Masters <jonmasters@gmail.com> wrote:
> >
> > I'd love to know what the state of discontig memory is like on 2.6
> > series ARM kernels and highmem too for that matter, but I've not had
> > chance to look at it (I'm usually a ppc guy).
>
> It works fine.
>
> The node mapping is performed by macros in asm-arm/arch-*/memory.h.

Hmmm...as it was in 2.4. I'll take a look for my general interest.

Jon.

Re: Discontiguous memory fun

[Martin J. Bligh]

--Jon Masters <jonmasters@gmail.com> wrote (on Monday, October 03, 2005 03:10:28 +0100):

> On 10/3/05, Marc Singer <elf@buici.com> wrote:
> 
>> On Sun, Oct 02, 2005 at 07:57:30PM +0100, Jon Masters wrote:
>> > Replying to my own post...
>> > 
>> > On 9/1/05, Jon Masters <jonmasters@gmail.com> wrote:
>> > 
>> > I'd love to know what the state of discontig memory is like on 2.6
>> > series ARM kernels and highmem too for that matter, but I've not had
>> > chance to look at it (I'm usually a ppc guy).
>> 
>> It works fine.
>> 
>> The node mapping is performed by macros in asm-arm/arch-*/memory.h.
> 
> Hmmm...as it was in 2.4. I'll take a look for my general interest.

If you're going to mess with it, please use sparsemem, not discontigmem.
The intent is to deprecate and delete the latter.

M.