[merged mm-stable] mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch removed from -mm tree

[merged mm-stable] mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/khugepaged: count collapses where khugepaged makes them
has been removed from the -mm tree.  Its filename was
     mm-khugepaged-count-collapses-where-khugepaged-makes-them.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: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
Subject: mm/khugepaged: count collapses where khugepaged makes them
Date: Wed, 14 Oct 2026 18:11:35 +0100

collapse_single_pmd() bumps khugepaged_pages_collapsed for its caller, and
tests cc->is_khugepaged to know whether it should: the counter belongs to
the daemon, and MADV_COLLAPSE must not touch it.

The daemon sees every result of every collapse it asks for, so it can keep
its own counter without the shared path testing who called.

Link: https://lore.kernel.org/20261014171145.3292736-3-kas@kernel.org
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Assisted-by: LLM
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <nico.pache@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Jann Horn <jannh@google.com>
---

 mm/khugepaged.c |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

--- a/mm/khugepaged.c~mm-khugepaged-count-collapses-where-khugepaged-makes-them
+++ a/mm/khugepaged.c
@@ -2841,10 +2841,8 @@ static enum scan_result collapse_single_
 
 	mmap_assert_locked(mm);
 
-	if (vma_is_anonymous(vma)) {
-		result = collapse_scan_pmd(mm, vma, addr, lock_dropped, cc);
-		goto end;
-	}
+	if (vma_is_anonymous(vma))
+		return collapse_scan_pmd(mm, vma, addr, lock_dropped, cc);
 
 	file = get_file(vma->vm_file);
 	pgoff = linear_page_index(vma, addr);
@@ -2880,9 +2878,6 @@ retry:
 			result = SCAN_SUCCEED;
 		mmap_read_unlock(mm);
 	}
-end:
-	if (cc->is_khugepaged && result == SCAN_SUCCEED)
-		++khugepaged_pages_collapsed;
 	return result;
 }
 
@@ -2959,6 +2954,8 @@ static void collapse_scan_mm_slot(unsign
 
 			*result = collapse_single_pmd(khugepaged_scan.address,
 						      vma, &lock_dropped, cc);
+			if (*result == SCAN_SUCCEED)
+				khugepaged_pages_collapsed++;
 			/* move to next address */
 			khugepaged_scan.address += HPAGE_PMD_SIZE;
 			if (lock_dropped)
_

Patches currently in -mm which might be from kas@kernel.org are