Re: [PATCH] i386: single node SPARSEMEM fix

Martin J. Bligh
2005-09-07T18:22:42Z

--On Wednesday, September 07, 2005 10:28:36 -0700 Dave Hansen <haveblue@us.ibm.com> wrote:

> On Tue, 2005-09-06 at 12:56 +0900, Magnus Damm wrote:
>> This patch for 2.6.13-git5 fixes single node sparsemem support. In the case
>> when multiple nodes are used, setup_memory() in arch/i386/mm/discontig.c calls
>> get_memcfg_numa() which calls memory_present(). The single node case with
>> setup_memory() in arch/i386/kernel/setup.c does not call memory_present()
>> without this patch, which breaks single node support.
>
> First of all, this is really a feature addition, not a bug fix. :)
>
> The reason we haven't included this so far is that we don't really have
> any machines that need sparsemem on i386 that aren't NUMA. So, we
> disabled it for now, and probably need to decide first why we need it
> before a patch like that goes in.

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.

M.