Re: [RFC 04/10] drivers: i915 selftest: use pgtable_has_pmd_leaves()
From: David Hildenbrand (Red Hat)
Date: Tue Dec 02 2025 - 05:51:12 EST
On 11/17/25 19:55, Luiz Capitulino wrote:
On 2025-11-17 12:30, David Hildenbrand (Red Hat) wrote:
On 06.11.25 22:28, Luiz Capitulino wrote:
igt_can_allocate_thp() uses has_transparente_hugepage() to check if
PMD-sized pages are supported, use pgtable_has_pmd_leaves() instead.
Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index bd08605a1611..c76aafa36d2b 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1316,7 +1316,7 @@ typedef struct drm_i915_gem_object *
static inline bool igt_can_allocate_thp(struct drm_i915_private *i915)
{
- return i915->mm.gemfs && has_transparent_hugepage();
+ return i915->mm.gemfs && pgtable_has_pmd_leaves();
On second thought, is it problematic that we might be losing the CONFIG_TRANSPARENT_HUGEPAGE check? Should we check for that separately?
That's a good point.
In this RFC, pgtable_has_pmd_leaves() should be functionally equivalent
to has_transparent_hugepage() so I think we're good. That beind said, I
also think that we should disentangle pgtable_has_pmd_leaves() from THP
now or in the future. When we do this the breakage you're spotting will
happen.
What about adding thp_has_pmd_support() which does:
return IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && pgtable_has_pmd_leaves();
Then I can convert all the cases you spotted to thp_has_pmd_support().
I hope we can avoid such a wrapper for the time being. Maybe we can just keep pgtable_has_pmd_leaves() glued to CONFIG_TRANSPARENT_HUGEPAGE for now, and leave untangling that for the next cleanup?
--
Cheers
David