Re: DISCONTIGMEM is deprecated

[Christoph Hellwig]

On Tue, Apr 23, 2019 at 07:49:57PM +0300, Meelis Roos wrote:
> > > ia64 (looks complicated ...)
> > 
> > Well as far as I can tell it was not even used 12 or so years ago on
> > Itanium when I worked on that stuff.
> 
> My notes tell that on UP ia64 (RX2620), !NUMA was broken with both
> SPARSEMEM and DISCONTIGMEM. NUMA+SPARSEMEM or !NUMA worked. Even
> NUMA+DISCONTIGMEM worked, that was my config on 2-CPU RX2660.

ia64 has a such a huge number of memory model choices.  Maybe we
need to cut it down to a small set that actually work.

That includes fund bits like the 'VIRTUAL_MEM_MAP' option where the
comment claims:

# VIRTUAL_MEM_MAP and FLAT_NODE_MEM_MAP are functionally equivalent.
# VIRTUAL_MEM_MAP has been retained for historical reasons.

but it still is selected as the default if sparsemem is not enabled..