Re: [RFC PATCH 2/5] mm, arch: unify vmemmap_populate altmap handling

[Michal Hocko]

On Mon 31-07-17 14:40:53, Gerald Schaefer wrote:
[...]
> > @@ -247,12 +248,12 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
> >  			 * use large frames even if they are only partially
> >  			 * used.
> >  			 * Otherwise we would have also page tables since
> > -			 * vmemmap_populate gets called for each section
> > +			 * __vmemmap_populate gets called for each section
> >  			 * separately. */
> >  			if (MACHINE_HAS_EDAT1) {
> >  				void *new_page;
> > 
> > -				new_page = vmemmap_alloc_block(PMD_SIZE, node);
> > +				new_page = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
> >  				if (!new_page)
> >  					goto out;
> >  				pmd_val(*pm_dir) = __pa(new_page) | sgt_prot;
> 
> There is another call to vmemmap_alloc_block() in this function, a couple
> of lines below, this should also be replaced by __vmemmap_alloc_block_buf().

I've noticed that one but in general I have only transformed PMD
mappings because we shouldn't even get to pte level if the forme works
AFAICS. Memory sections should be always 2MB aligned unless I am missing
something. Or is this not true?
-- 
Michal Hocko
SUSE Labs