Re: [RFC 06/10] mm: debug_vm_pgtable: use pgtable_has_pmd_leaves()

[David Hildenbrand (Red Hat)]

On 11/17/25 18:40, David Hildenbrand (Red Hat) wrote:
> On 06.11.25 22:28, Luiz Capitulino wrote:
> > debug_vm_pgtable calls has_transparent_hugepage() in multiple places to
> > check if PMD-sized pages are supported, use pgtable_has_pmd_leaves()
>
> Is that code even dealing with pages? Likely we really only want to
> check whether PMD leaves are supported, independent of any pages.

I recall that some arch protect certain pmd_* helpers under 
CONFIG_TRANSPARENT_HUGEPAGE.

But it's certainly something to explore, to see if we can just get rid 
of that without causing compile-time or runtime issues.

> > instead.
> >
> > Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
> > ---
> >    mm/debug_vm_pgtable.c | 20 ++++++++++----------
> >    1 file changed, 10 insertions(+), 10 deletions(-)
> >
> > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> > index 830107b6dd08..241b36c78ac9 100644
> > --- a/mm/debug_vm_pgtable.c
> > +++ b/mm/debug_vm_pgtable.c
> > @@ -170,7 +170,7 @@ static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
> >    	unsigned long val = idx, *ptr = &val;
> >    	pmd_t pmd;
> >    
> > -	if (!has_transparent_hugepage())
> > +	if (!pgtable_has_pmd_leaves())
> >    		return;
>
>
> All of these are currently protected by CONFIG_TRANSPARENT_HUGEPAGE, right?

IIUC, yes.


--
Cheers

David