Re: 32bit NUMA and fakeNUMA broken for AMD CPUs

[Tejun Heo <tj@kernel.org>]

On Wed, Jun 29, 2011 at 02:55:08PM +0200, Hans Rosenfeld wrote:
> On Wed, Jun 29, 2011 at 08:34:09AM -0400, Tejun Heo wrote:
> > So, mminit_verify_page_links() detects it while the last 512MiB
> > highmem chunk of node 0 is being initialized and freaks out.
> > 
> > We definitely need a safe guard to check NUMA node alignment and
> > disable NUMA if it requires finer granuality than supported by the
> > memory model.  If you use DISCONTIGMEM, which has 64MiB granuality,
> > instead, it works, right?
> 
> I had DISCONTIGMEM enabled in the kernel config, it does not work.

Hmmm?  The following is the relevant part from your .config.

  CONFIG_ARCH_DISCONTIGMEM_ENABLE=y
  CONFIG_ARCH_DISCONTIGMEM_DEFAULT=y
  CONFIG_ARCH_SPARSEMEM_ENABLE=y
  CONFIG_ARCH_SELECT_MEMORY_MODEL=y
  CONFIG_ILLEGAL_POINTER_VALUE=0
  CONFIG_SELECT_MEMORY_MODEL=y
  # CONFIG_DISCONTIGMEM_MANUAL is not set
  CONFIG_SPARSEMEM_MANUAL=y
  CONFIG_SPARSEMEM=y

And it selects SPARSEMEM via SPARSEMEM_MANUAL.  You need to choose
DISCONTIGMEM_MANUAL in "Processor type and features" -> "Memory
Model".

Thanks.

-- 
tejun