[PATCH v2 58/69] mm/hugetlb: Make HVO optimizable checks depend on generic logic

[Muchun Song <songmuchun@bytedance.com>]

Make hugetlb_vmemmap_optimizable() reuse the generic
order_vmemmap_optimizable() logic, and switch hugetlb boolean call sites
to use the dedicated helper directly.

This keeps HugeTLB-specific optimizable checks aligned with the generic
vmemmap optimization rules and avoids open-coding the size-based test.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/hugetlb.h |  2 +-
 mm/hugetlb.c            |  4 ++--
 mm/hugetlb_vmemmap.h    | 43 ++++++++++++++++++++---------------------
 3 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 82dbb9ebead8..2383adb22ce1 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -778,7 +778,7 @@ static inline unsigned long huge_page_mask(struct hstate *h)
 	return h->mask;
 }
 
-static inline unsigned int huge_page_order(struct hstate *h)
+static inline unsigned int huge_page_order(const struct hstate *h)
 {
 	return h->order;
 }
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 54ef7d12c585..bd136fc6aec0 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3351,7 +3351,7 @@ static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
 			folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, nid,
 					&node_states[N_MEMORY], NULL);
 			if (!folio && !list_empty(&folio_list) &&
-			    hugetlb_vmemmap_optimizable_size(h)) {
+			    hugetlb_vmemmap_optimizable(h)) {
 				prep_and_add_allocated_folios(h, &folio_list);
 				INIT_LIST_HEAD(&folio_list);
 				folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, nid,
@@ -3420,7 +3420,7 @@ static void __init hugetlb_pages_alloc_boot_node(unsigned long start, unsigned l
 	for (i = 0; i < num; ++i) {
 		struct folio *folio;
 
-		if (hugetlb_vmemmap_optimizable_size(h) &&
+		if (hugetlb_vmemmap_optimizable(h) &&
 		    (si_mem_available() == 0) && !list_empty(&folio_list)) {
 			prep_and_add_allocated_folios(h, &folio_list);
 			INIT_LIST_HEAD(&folio_list);
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
index dfd48be6b231..1765f8274220 100644
--- a/mm/hugetlb_vmemmap.h
+++ b/mm/hugetlb_vmemmap.h
@@ -18,22 +18,6 @@ long hugetlb_vmemmap_restore_folios(const struct hstate *h,
 void hugetlb_vmemmap_optimize_folio(const struct hstate *h, struct folio *folio);
 void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list);
 void hugetlb_vmemmap_optimize_bootmem_page(struct huge_bootmem_page *m);
-
-static inline unsigned int hugetlb_vmemmap_size(const struct hstate *h)
-{
-	return pages_per_huge_page(h) * sizeof(struct page);
-}
-
-/*
- * Return how many vmemmap size associated with a HugeTLB page that can be
- * optimized and can be freed to the buddy allocator.
- */
-static inline unsigned int hugetlb_vmemmap_optimizable_size(const struct hstate *h)
-{
-	int size = hugetlb_vmemmap_size(h) - OPTIMIZED_FOLIO_VMEMMAP_SIZE;
-
-	return size > 0 ? size : 0;
-}
 #else
 static inline int hugetlb_vmemmap_restore_folio(const struct hstate *h, struct folio *folio)
 {
@@ -56,11 +40,6 @@ static inline void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list
 {
 }
 
-static inline unsigned int hugetlb_vmemmap_optimizable_size(const struct hstate *h)
-{
-	return 0;
-}
-
 static inline void hugetlb_vmemmap_optimize_bootmem_page(struct huge_bootmem_page *m)
 {
 }
@@ -68,6 +47,26 @@ static inline void hugetlb_vmemmap_optimize_bootmem_page(struct huge_bootmem_pag
 
 static inline bool hugetlb_vmemmap_optimizable(const struct hstate *h)
 {
-	return hugetlb_vmemmap_optimizable_size(h) != 0;
+	if (!IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP))
+		return false;
+
+	return order_vmemmap_optimizable(huge_page_order(h));
+}
+
+static inline unsigned int hugetlb_vmemmap_size(const struct hstate *h)
+{
+	return pages_per_huge_page(h) * sizeof(struct page);
+}
+
+/*
+ * Return the size of the vmemmap area associated with a HugeTLB page
+ * that can be optimized.
+ */
+static inline unsigned int hugetlb_vmemmap_optimizable_size(const struct hstate *h)
+{
+	if (!hugetlb_vmemmap_optimizable(h))
+		return 0;
+
+	return hugetlb_vmemmap_size(h) - OPTIMIZED_FOLIO_VMEMMAP_SIZE;
 }
 #endif /* _LINUX_HUGETLB_VMEMMAP_H */
-- 
2.54.0