+ mm-merge-writeout-into-pageout.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: merge writeout into pageout
has been added to the -mm mm-unstable branch.  Its filename is
     mm-merge-writeout-into-pageout.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-merge-writeout-into-pageout.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: mm: merge writeout into pageout
Date: Mon, 1 Jun 2026 13:34:28 +0200

writeout is only called from pageout, and a straight flow at the end, so
merge the two functions.

Link: https://lore.kernel.org/20260601113449.3464734-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Baoquan He <baoquan.he@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |   63 +++++++++++++++++++++++---------------------------
 1 file changed, 29 insertions(+), 34 deletions(-)

--- a/mm/vmscan.c~mm-merge-writeout-into-pageout
+++ a/mm/vmscan.c
@@ -612,45 +612,14 @@ typedef enum {
 	PAGE_CLEAN,
 } pageout_t;
 
-static pageout_t writeout(struct folio *folio, struct address_space *mapping,
-		struct swap_iocb **plug, struct list_head *folio_list)
-{
-	int res;
-
-	folio_set_reclaim(folio);
-
-	/*
-	 * The large shmem folio can be split if CONFIG_THP_SWAP is not enabled
-	 * or we failed to allocate contiguous swap entries, in which case
-	 * the split out folios get added back to folio_list.
-	 */
-	if (shmem_mapping(mapping))
-		res = shmem_writeout(folio, plug, folio_list);
-	else
-		res = swap_writeout(folio, plug);
-
-	if (res < 0)
-		handle_write_error(mapping, folio, res);
-	if (res == AOP_WRITEPAGE_ACTIVATE) {
-		folio_clear_reclaim(folio);
-		return PAGE_ACTIVATE;
-	}
-
-	/* synchronous write? */
-	if (!folio_test_writeback(folio))
-		folio_clear_reclaim(folio);
-
-	trace_mm_vmscan_write_folio(folio);
-	node_stat_add_folio(folio, NR_VMSCAN_WRITE);
-	return PAGE_SUCCESS;
-}
-
 /*
  * pageout is called by shrink_folio_list() for each dirty folio.
  */
 static pageout_t pageout(struct folio *folio, struct address_space *mapping,
 			 struct swap_iocb **plug, struct list_head *folio_list)
 {
+	int res;
+
 	/*
 	 * We no longer attempt to writeback filesystem folios here, other
 	 * than tmpfs/shmem.  That's taken care of in page-writeback.
@@ -674,7 +643,33 @@ static pageout_t pageout(struct folio *f
 		return PAGE_ACTIVATE;
 	if (!folio_clear_dirty_for_io(folio))
 		return PAGE_CLEAN;
-	return writeout(folio, mapping, plug, folio_list);
+
+	folio_set_reclaim(folio);
+
+	/*
+	 * The large shmem folio can be split if CONFIG_THP_SWAP is not enabled
+	 * or we failed to allocate contiguous swap entries, in which case
+	 * the split out folios get added back to folio_list.
+	 */
+	if (shmem_mapping(mapping))
+		res = shmem_writeout(folio, plug, folio_list);
+	else
+		res = swap_writeout(folio, plug);
+
+	if (res < 0)
+		handle_write_error(mapping, folio, res);
+	if (res == AOP_WRITEPAGE_ACTIVATE) {
+		folio_clear_reclaim(folio);
+		return PAGE_ACTIVATE;
+	}
+
+	/* synchronous write? */
+	if (!folio_test_writeback(folio))
+		folio_clear_reclaim(folio);
+
+	trace_mm_vmscan_write_folio(folio);
+	node_stat_add_folio(folio, NR_VMSCAN_WRITE);
+	return PAGE_SUCCESS;
 }
 
 /*
_

Patches currently in -mm which might be from hch@lst.de are

mm-merge-writeout-into-pageout.patch