[PATCH v10 09/37] mm: hugetlb: thread user_addr through gigantic page allocation

[Michael S. Tsirkin]

Thread the user_addr parameter through alloc_gigantic_frozen_folio so that
gigantic page allocations can benefit from cache-friendly zeroing.

Note: the CMA path (hugetlb_cma_alloc_frozen_folio) does not
receive user_addr because CMA uses alloc_contig_frozen_pages,
not the _user variant. CMA-allocated pages get zeroed via
the normal __GFP_ZERO path without cache-friendly addressing.
This is acceptable: gigantic pages are rare and the CMA path
is a fallback when buddy allocation fails.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Assisted-by: Claude:claude-opus-4-6
---
 mm/hugetlb.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f3bc15a7889a..5d7e546565f5 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1355,7 +1355,7 @@ static struct folio *dequeue_hugetlb_folio_vma(struct hstate *h,
 
 #if defined(CONFIG_ARCH_HAS_GIGANTIC_PAGE) && defined(CONFIG_CONTIG_ALLOC)
 static struct folio *alloc_gigantic_frozen_folio(int order, gfp_t gfp_mask,
-		int nid, nodemask_t *nodemask)
+		int nid, nodemask_t *nodemask, unsigned long addr)
 {
 	struct folio *folio;
 
@@ -1366,13 +1366,15 @@ static struct folio *alloc_gigantic_frozen_folio(int order, gfp_t gfp_mask,
 	if (hugetlb_cma_exclusive_alloc())
 		return NULL;
 
-	folio = (struct folio *)alloc_contig_frozen_pages(1 << order, gfp_mask,
-							  nid, nodemask);
+	folio = (struct folio *)alloc_contig_frozen_pages_user(1 << order,
+							      gfp_mask,
+							      nid, nodemask,
+							      addr);
 	return folio;
 }
 #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE || !CONFIG_CONTIG_ALLOC */
 static struct folio *alloc_gigantic_frozen_folio(int order, gfp_t gfp_mask, int nid,
-					  nodemask_t *nodemask)
+					  nodemask_t *nodemask, unsigned long addr)
 {
 	return NULL;
 }
@@ -1842,7 +1844,8 @@ static struct folio *only_alloc_fresh_hugetlb_folio(struct hstate *h,
 		nid = numa_mem_id();
 
 	if (order_is_gigantic(order))
-		folio = alloc_gigantic_frozen_folio(order, gfp_mask, nid, nmask);
+		folio = alloc_gigantic_frozen_folio(order, gfp_mask, nid, nmask,
+						    addr);
 	else
 		folio = alloc_buddy_frozen_folio(order, gfp_mask, nid, nmask,
 						 node_alloc_noretry, addr);
-- 
MST