Re: [RFC 05/10] drivers: nvdimm: use pgtable_has_pmd_leaves()

From: David Hildenbrand (Red Hat)
Date: Mon Nov 17 2025 - 12:45:38 EST


On 06.11.25 22:28, Luiz Capitulino wrote:
nd_pfn_supported_alignments() and nd_pfn_supported_alignments() use
has_transparent_hugepage() to check if PMD-sized pages are supported,
use pgtable_has_pmd_leaves() instead.

Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
---
drivers/nvdimm/pfn_devs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 42b172fc5576..989f87f07e0c 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -94,7 +94,7 @@ static unsigned long *nd_pfn_supported_alignments(unsigned long *alignments)
alignments[0] = PAGE_SIZE;
- if (has_transparent_hugepage()) {
+ if (pgtable_has_pmd_leaves()) {
alignments[1] = HPAGE_PMD_SIZE;
if (has_transparent_pud_hugepage())

Yeah, that should become pgtable_has_pud_leaves() later.

alignments[2] = HPAGE_PUD_SIZE;
@@ -109,7 +109,7 @@ static unsigned long *nd_pfn_supported_alignments(unsigned long *alignments)
static unsigned long nd_pfn_default_alignment(void)
{
- if (has_transparent_hugepage())
+ if (pgtable_has_pmd_leaves())
return HPAGE_PMD_SIZE;
return PAGE_SIZE;
}

Similar question, what if the kernel would be built without CONFIG_TRANSPARENT_HUGEPAGE, would it matter here?

In that case, an additional eary "if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))" might do the trick.

--
Cheers

David