Re: [PATCH] i386: single node SPARSEMEM fix

[Magnus Damm <magnus.damm@gmail.com>]

On 9/8/05, Dave Hansen <haveblue@us.ibm.com> wrote:
> On Wed, 2005-09-07 at 11:22 -0700, Martin J. Bligh wrote:
> > CONFIG_NUMA was meant to (and did at one point) support both NUMA and flat
> > machines. This is essential in order for the distros to support it - same
> > will go for sparsemem.
> 
> That's a different issue.  The current code works if you boot a NUMA=y
> SPARSEMEM=y machine with a single node.  The current Kconfig options
> also enforce that SPARSEMEM depends on NUMA on i386.
> 
> Magnus would like to enable SPARSEMEM=y while CONFIG_NUMA=n.  That
> requires some Kconfig changes, as well as an extra memory present call.
> I'm questioning why we need to do that when we could never do
> DISCONTIG=y while NUMA=n on i386.

Actually, I do not really care about the Kconfig stuff. I just added
that to show you guys why and when the change in
arch/i386/kernel/setup.c was needed. So my main interest is to include
the fix to the single-node version of setup_memory(). This to sync up
the single-node case with the multiple-node version of setup_memory(),
and to make it easier for me and other people to start using sparsemem
om single-node (or non-NUMA if you prefer that) configurations.

/ magnus