Commit 0b43b8bc authored by Shivank Garg's avatar Shivank Garg Committed by Andrew Morton
Browse files

mm/khugepaged: clean up refcount check using folio_expected_ref_count() 

Use folio_expected_ref_count() instead of open-coded logic in
is_refcount_suitable().  This avoids code duplication and improves
clarity.

Drop is_refcount_suitable() as it is no longer needed.

Link: https://lkml.kernel.org/r/20250526182818.37978-2-shivankg@amd.com


Signed-off-by: default avatarShivank Garg <shivankg@amd.com>
Suggested-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarDev Jain <dev.jain@arm.com>
Reviewed-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Fengwei Yin <fengwei.yin@intel.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 66bce7af

mm/khugepaged.c

+2 −15
Original line number Diff line number Diff line
@@ -548,19 +548,6 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte, 
	}

}



static bool is_refcount_suitable(struct folio *folio)

{

	int expected_refcount = folio_mapcount(folio);



	if (!folio_test_anon(folio) || folio_test_swapcache(folio))

		expected_refcount += folio_nr_pages(folio);



	if (folio_test_private(folio))

		expected_refcount++;



	return folio_ref_count(folio) == expected_refcount;

}



static int __collapse_huge_page_isolate(struct vm_area_struct *vma,

					unsigned long address,

					pte_t *pte,
@@ -652,7 +639,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, 
		 * but not from this process. The other process cannot write to

		 * the page, only trigger CoW.

		 */

		if (!is_refcount_suitable(folio)) {

		if (folio_expected_ref_count(folio) != folio_ref_count(folio)) {

			folio_unlock(folio);

			result = SCAN_PAGE_COUNT;

			goto out;
@@ -1402,7 +1389,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, 
		 * has excessive GUP pins (i.e. 512).  Anyway the same check

		 * will be done again later the risk seems low.

		 */

		if (!is_refcount_suitable(folio)) {

		if (folio_expected_ref_count(folio) != folio_ref_count(folio)) {

			result = SCAN_PAGE_COUNT;

			goto out_unmap;

		}