Re: [PATCH v3 07/10] treewide: rename has_transparent_hugepage() to arch_has_pmd_leaves()
From: Luiz Capitulino
Date: Mon Apr 13 2026 - 11:33:06 EST
On 2026-04-09 15:43, Luiz Capitulino wrote:
On 2026-04-09 11:41, Zi Yan wrote:
On 8 Apr 2026, at 16:23, Luiz Capitulino wrote:
Now that all the has_transparent_hugepage() callers have been converted
to pgtable_has_pmd_leaves(), rename has_transparent_hugepage() to
arch_has_pmd_leaves() since that's what the helper checks for.
arch_has_pmd_leaves() is supposed to be called only by
init_arch_has_pmd_leaves(). The remaining exception is hugepage_init()
which will be converted in a future commit.
Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
---
arch/mips/include/asm/pgtable.h | 4 ++--
arch/mips/mm/tlb-r4k.c | 4 ++--
arch/powerpc/include/asm/book3s/64/hash-4k.h | 2 +-
arch/powerpc/include/asm/book3s/64/hash-64k.h | 2 +-
arch/powerpc/include/asm/book3s/64/pgtable.h | 10 +++++-----
arch/powerpc/include/asm/book3s/64/radix.h | 2 +-
arch/powerpc/mm/book3s64/hash_pgtable.c | 4 ++--
arch/s390/include/asm/pgtable.h | 4 ++--
arch/x86/include/asm/pgtable.h | 4 ++--
include/linux/pgtable.h | 4 ++--
mm/huge_memory.c | 2 +-
mm/memory.c | 2 +-
12 files changed, 22 insertions(+), 22 deletions(-)
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index fa7b935f947c..a97b788315e2 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -615,8 +615,8 @@ unsigned long io_remap_pfn_range_pfn(unsigned long pfn, unsigned long size);
/* We don't have hardware dirty/accessed bits, generic_pmdp_establish is fine.*/
#define pmdp_establish generic_pmdp_establish
-#define has_transparent_hugepage has_transparent_hugepage
-extern int has_transparent_hugepage(void);
+#define arch_has_pmd_leaves arch_has_pmd_leaves
+extern int arch_has_pmd_leaves(void);
static inline int pmd_trans_huge(pmd_t pmd)
{
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 24fe85fa169d..c423b5784337 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -434,7 +434,7 @@ void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-int has_transparent_hugepage(void)
+int arch_has_pmd_leaves(void)
{
static unsigned int mask = -1;
@@ -450,7 +450,7 @@ int has_transparent_hugepage(void)
}
return mask == PM_HUGE_MASK;
}
-EXPORT_SYMBOL(has_transparent_hugepage);
+EXPORT_SYMBOL(arch_has_pmd_leaves);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 8e5bd9902bed..6744c2287199 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -165,7 +165,7 @@ extern void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
extern pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
extern pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp);
-extern int hash__has_transparent_hugepage(void);
+extern int hash__arch_has_pmd_leaves(void);
#endif
#endif /* !__ASSEMBLER__ */
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 7deb3a66890b..9392aba5e5dc 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -278,7 +278,7 @@ extern void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
extern pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
extern pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp);
-extern int hash__has_transparent_hugepage(void);
+extern int hash__arch_has_pmd_leaves(void);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif /* __ASSEMBLER__ */
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 1a91762b455d..e4d9b884af5c 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1121,14 +1121,14 @@ static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
{
}
-extern int hash__has_transparent_hugepage(void);
-static inline int has_transparent_hugepage(void)
+extern int hash__arch_has_pmd_leaves(void);
+static inline int arch_has_pmd_leaves(void)
{
if (radix_enabled())
- return radix__has_transparent_hugepage();
- return hash__has_transparent_hugepage();
+ return radix__arch_has_pmd_leaves();
+ return hash__arch_has_pmd_leaves();
}
-#define has_transparent_hugepage has_transparent_hugepage
+#define arch_has_pmd_leaves arch_has_pmd_leaves
static inline int has_transparent_pud_hugepage(void)
{
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index da954e779744..c884a119cbd9 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -298,7 +298,7 @@ extern pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm,
pud_t radix__pudp_huge_get_and_clear(struct mm_struct *mm,
unsigned long addr, pud_t *pudp);
-static inline int radix__has_transparent_hugepage(void)
+static inline int radix__arch_has_pmd_leaves(void)
{
/* For radix 2M at PMD level means thp */
if (mmu_psize_defs[MMU_PAGE_2M].shift == PMD_SHIFT)
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
index ac2a24d15d2e..f7933c52cca9 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -370,7 +370,7 @@ pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
return old_pmd;
}
-int hash__has_transparent_hugepage(void)
+int hash__arch_has_pmd_leaves(void)
{
if (!mmu_has_feature(MMU_FTR_16M_PAGE))
@@ -399,7 +399,7 @@ int hash__has_transparent_hugepage(void)
return 1;
}
-EXPORT_SYMBOL_GPL(hash__has_transparent_hugepage);
+EXPORT_SYMBOL_GPL(hash__arch_has_pmd_leaves);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 1c3c3be93be9..e638d914fbad 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1776,8 +1776,8 @@ static inline int pmd_trans_huge(pmd_t pmd)
return pmd_leaf(pmd);
}
-#define has_transparent_hugepage has_transparent_hugepage
-static inline int has_transparent_hugepage(void)
+#define arch_has_pmd_leaves arch_has_pmd_leaves
+static inline int arch_has_pmd_leaves(void)
{
return cpu_has_edat1() ? 1 : 0;
}
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 1662c5a8f445..8fe95270b713 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -314,8 +314,8 @@ static inline int pud_trans_huge(pud_t pud)
}
#endif
-#define has_transparent_hugepage has_transparent_hugepage
-static inline int has_transparent_hugepage(void)
+#define arch_has_pmd_leaves arch_has_pmd_leaves
+static inline int arch_has_pmd_leaves(void)
{
return boot_cpu_has(X86_FEATURE_PSE);
}
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index c4c5282f795c..4b52a3abeab5 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -2222,8 +2222,8 @@ static inline void __init init_arch_has_pmd_leaves(void) { }
#endif
#endif
-#ifndef has_transparent_hugepage
-#define has_transparent_hugepage() IS_BUILTIN(CONFIG_TRANSPARENT_HUGEPAGE)
+#ifndef arch_has_pmd_leaves
+#define arch_has_pmd_leaves() IS_BUILTIN(CONFIG_TRANSPARENT_HUGEPAGE)
Should this be
#define arch_has_pmd_leaves() 1
?
Since all has_transparent_hugepage() is converted
to IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && pgtable_has_pmd_leaves()
and pgtable_has_pmd_leaves() is basically arch_has_pmd_leaves().
The IS_ENABLED() is the same as IS_BUILTIN() here.
Before this patch, if an arch does not define has_transparent_hugepage,
has_transparent_hugepage() basically means the arch supports PMD leaves
and software controls the availability of THP. Now you rename it to
arch_has_pmd_leaves() and setting it to 1 reflects its actual semantics.
Yes, you're right that the intended future semantics is: if an arch
doesn't define arch_has_pmd_leaves() then the kernel assumes it supports
PMD pages.
I originally kept arch_has_pmd_leaves() tied to THP because I was afraid
of breaking the current callers who want to use PMD pages with THP. But,
as you say, they should all be checking for
IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) now.
I'll look into implementing your suggestion for v4.
In taking a second look at this, I realized that a better default should
be:
#define arch_has_pmd_leaves() IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE)
Since archs defining CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE should
support PMD pages. This is also consistent with
has_transparent_pud_hugepage().