[merged mm-stable] mm-khugepaged-support-shmem-mthp-collapse.patch removed from -mm tree

[Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>]

The quilt patch titled
     Subject: mm: khugepaged: support shmem mTHP collapse
has been removed from the -mm tree.  Its filename was
     mm-khugepaged-support-shmem-mthp-collapse.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: khugepaged: support shmem mTHP collapse
Date: Tue, 20 Aug 2024 17:49:16 +0800

Shmem already supports the allocation of mTHP, but khugepaged does not yet
support collapsing mTHP folios.  Now khugepaged is ready to support mTHP,
and this patch enables the collapse of shmem mTHP.

Link: https://lkml.kernel.org/r/b9da76aab4276eb6e5d12c479af2b5eea5b4575d.1724140601.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Barry Song <21cnbao@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/khugepaged.c |   28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

--- a/mm/khugepaged.c~mm-khugepaged-support-shmem-mthp-collapse
+++ a/mm/khugepaged.c
@@ -1843,7 +1843,7 @@ static int collapse_file(struct mm_struc
 		}
 	} while (1);
 
-	for (index = start; index < end; index++) {
+	for (index = start; index < end;) {
 		xas_set(&xas, index);
 		folio = xas_load(&xas);
 
@@ -1862,6 +1862,7 @@ static int collapse_file(struct mm_struc
 					}
 				}
 				nr_none++;
+				index++;
 				continue;
 			}
 
@@ -1943,12 +1944,10 @@ static int collapse_file(struct mm_struc
 		 * we locked the first folio, then a THP might be there already.
 		 * This will be discovered on the first iteration.
 		 */
-		if (folio_test_large(folio)) {
-			result = folio_order(folio) == HPAGE_PMD_ORDER &&
-					folio->index == start
-					/* Maybe PMD-mapped */
-					? SCAN_PTE_MAPPED_HUGEPAGE
-					: SCAN_PAGE_COMPOUND;
+		if (folio_order(folio) == HPAGE_PMD_ORDER &&
+		    folio->index == start) {
+			/* Maybe PMD-mapped */
+			result = SCAN_PTE_MAPPED_HUGEPAGE;
 			goto out_unlock;
 		}
 
@@ -2009,6 +2008,7 @@ static int collapse_file(struct mm_struc
 		 * Accumulate the folios that are being collapsed.
 		 */
 		list_add_tail(&folio->lru, &pagelist);
+		index += folio_nr_pages(folio);
 		continue;
 out_unlock:
 		folio_unlock(folio);
@@ -2261,16 +2261,10 @@ static int hpage_collapse_scan_file(stru
 			continue;
 		}
 
-		/*
-		 * TODO: khugepaged should compact smaller compound pages
-		 * into a PMD sized page
-		 */
-		if (folio_test_large(folio)) {
-			result = folio_order(folio) == HPAGE_PMD_ORDER &&
-					folio->index == start
-					/* Maybe PMD-mapped */
-					? SCAN_PTE_MAPPED_HUGEPAGE
-					: SCAN_PAGE_COMPOUND;
+		if (folio_order(folio) == HPAGE_PMD_ORDER &&
+		    folio->index == start) {
+			/* Maybe PMD-mapped */
+			result = SCAN_PTE_MAPPED_HUGEPAGE;
 			/*
 			 * For SCAN_PTE_MAPPED_HUGEPAGE, further processing
 			 * by the caller won't touch the page cache, and so
_

Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are