+ mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: hugetlb: allocate frozen pages in alloc_gigantic_folio()
has been added to the -mm mm-new branch.  Its filename is
     mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm: hugetlb: allocate frozen pages in alloc_gigantic_folio()
Date: Tue, 2 Sep 2025 20:48:20 +0800

The alloc_gigantic_folio() will allocate a folio by alloc_contig_range()
with refcount increated and then freeze it, convert to allocate a frozen
folio directly to remove the atomic operation about folio refcount, also
saving atomic operation during __update_and_free_hugetlb_folio too.

Rename some functions to make them more self-explanatory,

  folio_alloc_gigantic		-> folio_alloc_frozen_gigantic
  cma_alloc/free_folio		-> cma_alloc/free_frozen_folio
  hugetlb_cma_alloc/free_folio	-> hugetlb_cma_alloc/free_frozen_folio

Link: https://lkml.kernel.org/r/20250902124820.3081488-10-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/cma.h |    8 +++---
 include/linux/gfp.h |   14 +++++------
 mm/cma.c            |   22 ++++++++++++------
 mm/hugetlb.c        |   50 ++++++++----------------------------------
 mm/hugetlb_cma.c    |   13 +++++-----
 mm/hugetlb_cma.h    |   10 ++++----
 6 files changed, 47 insertions(+), 70 deletions(-)

--- a/include/linux/cma.h~mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio
+++ a/include/linux/cma.h
@@ -57,16 +57,16 @@ extern bool cma_intersects(struct cma *c
 extern void cma_reserve_pages_on_error(struct cma *cma);
 
 #ifdef CONFIG_CMA
-struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp);
-bool cma_free_folio(struct cma *cma, const struct folio *folio);
+struct folio *cma_alloc_frozen_folio(struct cma *cma, int order, gfp_t gfp);
+bool cma_free_frozen_folio(struct cma *cma, const struct folio *folio);
 bool cma_validate_zones(struct cma *cma);
 #else
-static inline struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp)
+static inline struct folio *cma_alloc_frozen_folio(struct cma *cma, int order, gfp_t gfp)
 {
 	return NULL;
 }
 
-static inline bool cma_free_folio(struct cma *cma, const struct folio *folio)
+static inline bool cma_free_frozen_folio(struct cma *cma, const struct folio *folio)
 {
 	return false;
 }
--- a/include/linux/gfp.h~mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio
+++ a/include/linux/gfp.h
@@ -447,26 +447,26 @@ struct page *alloc_contig_frozen_pages_n
 void free_contig_range(unsigned long pfn, unsigned long nr_pages);
 
 #ifdef CONFIG_CONTIG_ALLOC
-static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
-							int nid, nodemask_t *node)
+static inline struct folio *folio_alloc_frozen_gigantic_noprof(int order,
+		gfp_t gfp, int nid, nodemask_t *node)
 {
 	struct page *page;
 
 	if (WARN_ON(!order || !(gfp & __GFP_COMP)))
 		return NULL;
 
-	page = alloc_contig_pages_noprof(1 << order, gfp, nid, node);
+	page = alloc_contig_frozen_pages_noprof(1 << order, gfp, nid, node);
 
 	return page ? page_folio(page) : NULL;
 }
 #else
-static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
-							int nid, nodemask_t *node)
+static inline struct folio *folio_alloc_frozen_gigantic_noprof(int order,
+		gfp_t gfp, int nid, nodemask_t *node)
 {
 	return NULL;
 }
 #endif
-/* This should be paired with folio_put() rather than free_contig_range(). */
-#define folio_alloc_gigantic(...) alloc_hooks(folio_alloc_gigantic_noprof(__VA_ARGS__))
+/* This must be paired with free_frozen_pages() rather than free_contig_range(). */
+#define folio_alloc_frozen_gigantic(...) alloc_hooks(folio_alloc_frozen_gigantic_noprof(__VA_ARGS__))
 
 #endif /* __LINUX_GFP_H */
--- a/mm/cma.c~mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio
+++ a/mm/cma.c
@@ -933,20 +933,21 @@ struct page *cma_alloc(struct cma *cma,
 			   ACR_FLAGS_CMA);
 }
 
-struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp)
+struct folio *cma_alloc_frozen_folio(struct cma *cma, int order, gfp_t gfp)
 {
 	struct page *page;
 
 	if (WARN_ON(!order || !(gfp & __GFP_COMP)))
 		return NULL;
 
-	page = __cma_alloc(cma, 1 << order, order, gfp, ACR_FLAGS_CMA);
+	page = __cma_alloc(cma, 1 << order, order, gfp,
+			   ACR_FLAGS_CMA | ACR_FLAGS_FROZEN);
 
 	return page ? page_folio(page) : NULL;
 }
 
 static bool __cma_release(struct cma *cma, const struct page *pages,
-			  unsigned long count)
+			  unsigned long count, bool frozen_page)
 {
 	unsigned long pfn, end;
 	int r;
@@ -969,7 +970,14 @@ static bool __cma_release(struct cma *cm
 	if (r == cma->nranges)
 		return false;
 
-	free_contig_range(pfn, count);
+	if (frozen_page) {
+		struct page *head_page = compound_head((struct page *)pages);
+
+		free_frozen_pages(head_page, compound_order(head_page));
+	} else {
+		free_contig_range(pfn, count);
+	}
+
 	cma_clear_bitmap(cma, cmr, pfn, count);
 	cma_sysfs_account_release_pages(cma, count);
 	trace_cma_release(cma->name, pfn, pages, count);
@@ -990,15 +998,15 @@ static bool __cma_release(struct cma *cm
 bool cma_release(struct cma *cma, const struct page *pages,
 		 unsigned long count)
 {
-	return __cma_release(cma, pages, count);
+	return __cma_release(cma, pages, count, false);
 }
 
-bool cma_free_folio(struct cma *cma, const struct folio *folio)
+bool cma_free_frozen_folio(struct cma *cma, const struct folio *folio)
 {
 	if (WARN_ON(!folio_test_large(folio)))
 		return false;
 
-	return __cma_release(cma, &folio->page, folio_nr_pages(folio));
+	return __cma_release(cma, &folio->page, folio_nr_pages(folio), true);
 }
 
 int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
--- a/mm/hugetlb.c~mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio
+++ a/mm/hugetlb.c
@@ -125,16 +125,6 @@ static void hugetlb_unshare_pmds(struct
 		unsigned long start, unsigned long end, bool take_locks);
 static struct resv_map *vma_resv_map(struct vm_area_struct *vma);
 
-static void hugetlb_free_folio(struct folio *folio)
-{
-	if (folio_test_hugetlb_cma(folio)) {
-		hugetlb_cma_free_folio(folio);
-		return;
-	}
-
-	folio_put(folio);
-}
-
 static inline bool subpool_is_free(struct hugepage_subpool *spool)
 {
 	if (spool->count)
@@ -1472,43 +1462,20 @@ static int hstate_next_node_to_free(stru
 		nr_nodes--)
 
 #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
-#ifdef CONFIG_CONTIG_ALLOC
 static struct folio *alloc_gigantic_folio(int order, gfp_t gfp_mask,
 		int nid, nodemask_t *nodemask)
 {
 	struct folio *folio;
-	bool retried = false;
-
-retry:
-	folio = hugetlb_cma_alloc_folio(order, gfp_mask, nid, nodemask);
-	if (!folio) {
-		if (hugetlb_cma_exclusive_alloc())
-			return NULL;
-
-		folio = folio_alloc_gigantic(order, gfp_mask, nid, nodemask);
-		if (!folio)
-			return NULL;
-	}
 
-	if (folio_ref_freeze(folio, 1))
+	folio = hugetlb_cma_alloc_frozen_folio(order, gfp_mask, nid, nodemask);
+	if (folio)
 		return folio;
 
-	pr_warn("HugeTLB: unexpected refcount on PFN %lu\n", folio_pfn(folio));
-	hugetlb_free_folio(folio);
-	if (!retried) {
-		retried = true;
-		goto retry;
-	}
-	return NULL;
-}
+	if (hugetlb_cma_exclusive_alloc())
+		return NULL;
 
-#else /* !CONFIG_CONTIG_ALLOC */
-static struct folio *alloc_gigantic_folio(int order, gfp_t gfp_mask, int nid,
-					  nodemask_t *nodemask)
-{
-	return NULL;
+	return folio_alloc_frozen_gigantic(order, gfp_mask, nid, nodemask);
 }
-#endif /* CONFIG_CONTIG_ALLOC */
 
 #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */
 static struct folio *alloc_gigantic_folio(int order, gfp_t gfp_mask, int nid,
@@ -1641,9 +1608,12 @@ static void __update_and_free_hugetlb_fo
 	if (unlikely(folio_test_hwpoison(folio)))
 		folio_clear_hugetlb_hwpoison(folio);
 
-	folio_ref_unfreeze(folio, 1);
+	VM_BUG_ON_FOLIO(folio_ref_count(folio), folio);
 
-	hugetlb_free_folio(folio);
+	if (folio_test_hugetlb_cma(folio))
+		hugetlb_cma_free_frozen_folio(folio);
+	else
+		free_frozen_pages(&folio->page, folio_order(folio));
 }
 
 /*
--- a/mm/hugetlb_cma.c~mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio
+++ a/mm/hugetlb_cma.c
@@ -18,29 +18,28 @@ static unsigned long hugetlb_cma_size_in
 static bool hugetlb_cma_only;
 static unsigned long hugetlb_cma_size __initdata;
 
-void hugetlb_cma_free_folio(struct folio *folio)
+void hugetlb_cma_free_frozen_folio(struct folio *folio)
 {
 	int nid = folio_nid(folio);
 
-	WARN_ON_ONCE(!cma_free_folio(hugetlb_cma[nid], folio));
+	WARN_ON_ONCE(!cma_free_frozen_folio(hugetlb_cma[nid], folio));
 }
 
-
-struct folio *hugetlb_cma_alloc_folio(int order, gfp_t gfp_mask,
-				      int nid, nodemask_t *nodemask)
+struct folio *hugetlb_cma_alloc_frozen_folio(int order, gfp_t gfp_mask,
+		int nid, nodemask_t *nodemask)
 {
 	int node;
 	struct folio *folio = NULL;
 
 	if (hugetlb_cma[nid])
-		folio = cma_alloc_folio(hugetlb_cma[nid], order, gfp_mask);
+		folio = cma_alloc_frozen_folio(hugetlb_cma[nid], order, gfp_mask);
 
 	if (!folio && !(gfp_mask & __GFP_THISNODE)) {
 		for_each_node_mask(node, *nodemask) {
 			if (node == nid || !hugetlb_cma[node])
 				continue;
 
-			folio = cma_alloc_folio(hugetlb_cma[node], order, gfp_mask);
+			folio = cma_alloc_frozen_folio(hugetlb_cma[node], order, gfp_mask);
 			if (folio)
 				break;
 		}
--- a/mm/hugetlb_cma.h~mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio
+++ a/mm/hugetlb_cma.h
@@ -3,8 +3,8 @@
 #define _LINUX_HUGETLB_CMA_H
 
 #ifdef CONFIG_CMA
-void hugetlb_cma_free_folio(struct folio *folio);
-struct folio *hugetlb_cma_alloc_folio(int order, gfp_t gfp_mask,
+void hugetlb_cma_free_frozen_folio(struct folio *folio);
+struct folio *hugetlb_cma_alloc_frozen_folio(int order, gfp_t gfp_mask,
 				      int nid, nodemask_t *nodemask);
 struct huge_bootmem_page *hugetlb_cma_alloc_bootmem(struct hstate *h, int *nid,
 						    bool node_exact);
@@ -14,12 +14,12 @@ unsigned long hugetlb_cma_total_size(voi
 void hugetlb_cma_validate_params(void);
 bool hugetlb_early_cma(struct hstate *h);
 #else
-static inline void hugetlb_cma_free_folio(struct folio *folio)
+static inline void hugetlb_cma_free_frozen_folio(struct folio *folio)
 {
 }
 
-static inline struct folio *hugetlb_cma_alloc_folio(int order, gfp_t gfp_mask,
-		int nid, nodemask_t *nodemask)
+static inline struct folio *hugetlb_cma_alloc_frozen_folio(int order,
+		gfp_t gfp_mask, int nid, nodemask_t *nodemask)
 {
 	return NULL;
 }
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

mm-hugetlb-convert-to-use-more-alloc_fresh_hugetlb_folio.patch
mm-hugetlb-convert-to-account_new_hugetlb_folio.patch
mm-hugetlb-directly-pass-order-when-allocate-a-hugetlb-folio.patch
mm-hugetlb-remove-struct-hstate-from-init_new_hugetlb_folio.patch
mm-hugeltb-check-numa_no_node-in-only_alloc_fresh_hugetlb_folio.patch
mm-page_alloc-add-alloc_contig_frozen_pages.patch
mm-cma-add-alloc-flags-for-__cma_alloc.patch
mm-cma-add-__cma_release.patch
mm-hugetlb-allocate-frozen-pages-in-alloc_gigantic_folio.patch