Re: 2G memory split

[Jens Axboe <axboe@suse.de>]

On Tue, Jan 10 2006, Byron Stanoszek wrote:
> On Tue, 10 Jan 2006, Jens Axboe wrote:
> 
> >>yes, i made it totally configurable in 2.4 days: 1:3, 2/2 and 3:1 splits
> >>were possible. It was a larger patch to enable all this across x86, but
> >>the Kconfig portion was removed a bit later because people _frequently_
> >>misconfigured their kernels and then complained about the results.
> >
> >How is this different than all other sorts of misconfigurations? As far
> >as I can tell, the biggest "problem" for some is if they depend on some
> >binary module that will of course break with a different page offset.
> >
> >For simplicity, I didn't add more than the 2/2 split, where we could add
> >even a 3/1 kernel/user or a 0.5/3.5 (I think sles8 had this).
> 
> I prefer setting __PAGE_OFFSET to (0x78000000) on machines with 2GB of RAM.
> This seems to let the kernel use the full 2GB of memory, rather than just
> 1920-1984 MB (at least back in 2.4 days).

That might indeed be a good idea for 2G/2G, in the same sense that
0xC0000000 is a silly default because of the many 1G machines out there.

-- 
Jens Axboe