[PATCH v4 38/38] mm/huge_memory: remove vma_is_special_huge()
flat view
From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Date: 2026-10-03 16:46:34
Also in:
bpf, fuse-devel, kvm, kvm-riscv, kvmarm, linux-arch, linux-doc, linux-fbdev, linux-fsdevel, linux-mm, linux-perf-users, linux-rdma, linux-riscv, linux-s390, linux-scsi, linux-sound, linux-trace-kernel, linux-usb, lkml, selinux, sparclinux
Subsystem:
memory management, memory management - thp (transparent huge page), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
1 review trailer (1 from subsystem maintainers); queued in linux-next as 4dde2fc225c1 on 2026-10-07.
vma_is_special_huge() tests whether either the VMA_PFNMAP_BIT or VMA_MIXEDMAP_BIT is set (i.e. whether the VMA is not mm-managed), but with a DAX carve-out. DAX however no longer sets VMA_MIXEDMAP_BIT, so this carve-out is no longer required. Therefore test for !vma_is_mm_managed() instead and also drop the VMA_IO_BIT check, as it is now redundant since it is enforced that mm-managed mappings may not set VMA_IO_BIT. This also eliminates another overloaded use of 'special' within mm. No functional change intended. Acked-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> --- mm/huge_memory.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 83dd63b04568..000c4bb50f71 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c@@ -110,14 +110,6 @@ static inline bool file_thp_enabled(const struct vm_area_struct *vma) return S_ISREG(inode->i_mode); } -/* If returns true, we are unable to access the VMA's folios. */ -static bool vma_is_special_huge(const struct vm_area_struct *vma) -{ - if (vma_is_dax(vma)) - return false; - return vma_test_any(vma, VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT); -} - static bool vma_file_bypass_thp_tuneables(const struct vm_area_struct *vma, enum tva_type type) {
@@ -192,7 +184,7 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, /* Check the intersection of requested and supported orders. */ if (vma_is_anonymous(vma)) supported_orders = THP_ORDERS_ALL_ANON; - else if (vma_is_dax(vma) || vma_is_special_huge(vma)) + else if (vma_is_dax(vma) || !vma_is_mm_managed(vma)) supported_orders = THP_ORDERS_ALL_SPECIAL_DAX; else supported_orders = THP_ORDERS_ALL_FILE_DEFAULT;
@@ -3066,7 +3058,7 @@ int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, orig_pud = pudp_huge_get_and_clear_full(vma, addr, pud, tlb->fullmm); arch_check_zapped_pud(vma, orig_pud); tlb_remove_pud_tlb_entry(tlb, pud, addr); - if (vma_is_special_huge(vma)) { + if (!vma_is_mm_managed(vma)) { spin_unlock(ptl); /* No zero page support yet */ } else {
@@ -3222,7 +3214,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, */ if (arch_needs_pgtable_deposit()) zap_deposited_table(mm, pmd); - if (vma_is_special_huge(vma)) + if (!vma_is_mm_managed(vma)) return; if (unlikely(pmd_is_migration_entry(old_pmd))) { const softleaf_t old_entry = softleaf_from_pmd(old_pmd);
@@ -4765,9 +4757,7 @@ static inline bool vma_not_suitable_for_thp_split(struct vm_area_struct *vma) { if (vma_is_dax(vma)) return true; - if (vma_is_special_huge(vma)) - return true; - if (vma_test(vma, VMA_IO_BIT)) + if (!vma_is_mm_managed(vma)) return true; if (vma_is_hugetlb(vma)) return true;
--
2.55.0