+ mm-page_io-use-swap-entries-directly-in-zeromap-helpers.patch added to mm-new branch

+ mm-page_io-use-swap-entries-directly-in-zeromap-helpers.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/page_io: use swap entries directly in zeromap helpers
has been added to the -mm mm-new branch.  Its filename is
     mm-page_io-use-swap-entries-directly-in-zeromap-helpers.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_io-use-swap-entries-directly-in-zeromap-helpers.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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and is updated there most days

------------------------------------------------------
From: Tal Zussman <tz2294@columbia.edu>
Subject: mm/page_io: use swap entries directly in zeromap helpers
Date: Sat, 29 Aug 2026 15:09:02 -0400

Increment swp_entry_t::val directly instead of recomputing each entry with
page_swap_entry().  This removes the last struct page usage in page_io.c
and saves one call to compound_head() per page.

Link: https://lore.kernel.org/20260829-b4-page_io-folios-v2-3-649728091117@columbia.edu
Signed-off-by: Tal Zussman <tz2294@columbia.edu>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_io.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/mm/page_io.c~mm-page_io-use-swap-entries-directly-in-zeromap-helpers
+++ a/mm/page_io.c
@@ -160,7 +160,7 @@ static void swap_zeromap_folio_set(struc
 	struct obj_cgroup *objcg = get_obj_cgroup_from_folio(folio);
 	int nr_pages = folio_nr_pages(folio);
 	struct swap_cluster_info *ci;
-	swp_entry_t entry;
+	swp_entry_t entry = folio->swap;
 	unsigned int i;
 
 	VM_WARN_ON_ONCE_FOLIO(!folio_test_swapcache(folio), folio);
@@ -168,8 +168,8 @@ static void swap_zeromap_folio_set(struc
 
 	ci = swap_cluster_get_and_lock(folio);
 	for (i = 0; i < folio_nr_pages(folio); i++) {
-		entry = page_swap_entry(folio_page(folio, i));
 		__swap_table_set_zero(ci, swp_cluster_offset(entry));
+		entry.val++;
 	}
 	swap_cluster_unlock(ci);
 
@@ -183,7 +183,7 @@ static void swap_zeromap_folio_set(struc
 static void swap_zeromap_folio_clear(struct folio *folio)
 {
 	struct swap_cluster_info *ci;
-	swp_entry_t entry;
+	swp_entry_t entry = folio->swap;
 	unsigned int i;
 
 	VM_WARN_ON_ONCE_FOLIO(!folio_test_swapcache(folio), folio);
@@ -191,8 +191,8 @@ static void swap_zeromap_folio_clear(str
 
 	ci = swap_cluster_get_and_lock(folio);
 	for (i = 0; i < folio_nr_pages(folio); i++) {
-		entry = page_swap_entry(folio_page(folio, i));
 		__swap_table_clear_zero(ci, swp_cluster_offset(entry));
+		entry.val++;
 	}
 	swap_cluster_unlock(ci);
 }
_

Patches currently in -mm which might be from tz2294@columbia.edu are

mm-page_io-convert-write-completion-handlers-to-folios.patch
mm-remove-pagereclaim.patch
mm-page_io-use-swap-entries-directly-in-zeromap-helpers.patch
mm-page_io-rename-bio_associate_blkg_from_page.patch
mm-page_io-refer-to-folios-in-swap_writeout-comments.patch
mm-swap-rename-__swap_writepage-to-__swap_writeout.patch