+ mm-page_alloc-batch-vmstat-updates-in-expand.patch added to mm-unstable branch

+ mm-page_alloc-batch-vmstat-updates-in-expand.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: page_alloc: batch vmstat updates in expand()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-page_alloc-batch-vmstat-updates-in-expand.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-batch-vmstat-updates-in-expand.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: Johannes Weiner <hannes@cmpxchg.org>
Subject: mm: page_alloc: batch vmstat updates in expand()
Date: Wed, 27 Mar 2024 15:01:11 -0400

expand() currently updates vmstat for every subpage.  This is unnecessary,
since they're all of the same zone and migratetype.

Count added pages locally, then do a single vmstat update.

Link: https://lkml.kernel.org/r/20240327190111.GC7597@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/mm/page_alloc.c~mm-page_alloc-batch-vmstat-updates-in-expand
+++ a/mm/page_alloc.c
@@ -1341,6 +1341,7 @@ static inline void expand(struct zone *z
 	int low, int high, int migratetype)
 {
 	unsigned long size = 1 << high;
+	unsigned long nr_added = 0;
 
 	while (high > low) {
 		high--;
@@ -1356,9 +1357,11 @@ static inline void expand(struct zone *z
 		if (set_page_guard(zone, &page[size], high))
 			continue;
 
-		add_to_free_list(&page[size], zone, high, migratetype, false);
+		__add_to_free_list(&page[size], zone, high, migratetype, false);
 		set_buddy_order(&page[size], high);
+		nr_added += size;
 	}
+	account_freepages(zone, nr_added, migratetype);
 }
 
 static void check_new_page_bad(struct page *page)
_

Patches currently in -mm which might be from hannes@cmpxchg.org are

mm-zswap-optimize-zswap-pool-size-tracking.patch
mm-zpool-return-pool-size-in-pages.patch
mm-page_alloc-remove-pcppage-migratetype-caching.patch
mm-page_alloc-optimize-free_unref_folios.patch
mm-page_alloc-fix-up-block-types-when-merging-compatible-blocks.patch
mm-page_alloc-move-free-pages-when-converting-block-during-isolation.patch
mm-page_alloc-fix-move_freepages_block-range-error.patch
mm-page_alloc-fix-freelist-movement-during-block-conversion.patch
mm-page_alloc-close-migratetype-race-between-freeing-and-stealing.patch
mm-page_isolation-prepare-for-hygienic-freelists.patch
mm-page_isolation-prepare-for-hygienic-freelists-fix.patch
mm-page_alloc-consolidate-free-page-accounting.patch
mm-page_alloc-consolidate-free-page-accounting-fix.patch
mm-page_alloc-consolidate-free-page-accounting-fix-2.patch
mm-page_alloc-batch-vmstat-updates-in-expand.patch