Re: [PATCH 2/4] mm/huge_memory: move to next folio after folio_split() succeeds.

On 7 Aug 2025, at 4:45, Wei Yang wrote:

On Tue, Aug 05, 2025 at 10:20:43PM -0400, Zi Yan wrote:

...

Current behavior is to move to next PAGE_SIZE and split, but that makes it hard to check after-split folio orders. This is a preparation patch to allow more precise split_huge_page_test check in an upcoming commit.

split_folio_to_order() part is not changed, since split_pte_mapped_thp test relies on its current behavior.

Signed-off-by: Zi Yan ziy@nvidia.com

mm/huge_memory.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 8a11c2d402d4..b2ce8ac0c5a9 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -4341,6 +4341,7 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start, struct folio *folio; struct address_space *mapping; unsigned int target_order = new_order;

• long nr_pages;
  
  

  if (!vma) break;

@@ -4358,6 +4359,8 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start, if (!is_transparent_hugepage(folio)) goto next;

• nr_pages = folio_nr_pages(folio);
  

Could be folio_large_nr_pages()?

Sure.

...

if (!folio_test_anon(folio)) {
	mapping = folio->mapping;
	target_order = max(new_order,

@@ -4385,15 +4388,16 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start, if (!folio_test_anon(folio) && folio->mapping != mapping) goto unlock;

• if (in_folio_offset < 0 ||
  

•     in_folio_offset >= folio_nr_pages(folio)) {
  

• if (in_folio_offset < 0 || in_folio_offset >= nr_pages) {
  if (!split_folio_to_order(folio, target_order))
  	split++;
  

  } else {

• 	struct page *split_at = folio_page(folio,
  

• 					   in_folio_offset);
  

• 	if (!folio_split(folio, target_order, split_at, NULL))
  

• 	struct page *split_at =
  

• 		folio_page(folio, in_folio_offset);
  

• 	if (!folio_split(folio, target_order, split_at, NULL)) {
  	split++;
  

• 		addr += PAGE_SIZE * nr_pages;
  

• 	}
  

  }

unlock: @@ -4438,8 +4442,8 @@ static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start, if (IS_ERR(candidate)) goto out;

• pr_debug("split file-backed THPs in file: %s, page offset: [0x%lx - 0x%lx]\n",

•  file_path, off_start, off_end);
  

• pr_debug("split file-backed THPs in file: %s, page offset: [0x%lx - 0x%lx], new_order %u in_folio_offset %ld\n",

•  file_path, off_start, off_end, new_order, in_folio_offset);
  
  

How about move this part into patch 1?

Sure. I missed it. Thanks.

...

mapping = candidate->f_mapping; min_order = mapping_min_folio_order(mapping); -- 2.47.2

-- Wei Yang Help you, Help me

-- Best Regards, Yan, Zi