[merged mm-stable] page_counter-reduce-struct-page_counter-size.patch removed from -mm tree

[merged mm-stable] page_counter-reduce-struct-page_counter-size.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: page_counter: reduce struct page_counter size
has been removed from the -mm tree.  Its filename was
     page_counter-reduce-struct-page_counter-size.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: Shakeel Butt <shakeel.butt@linux.dev>
Subject: page_counter: reduce struct page_counter size
Date: Thu, 27 Feb 2025 23:58:08 -0800

The struct page_counter has explicit padding for better cache alignment. 
The commit c6f53ed8f213a ("mm, memcg: cg2 memory{.swap,}.peak write
handlers") added a field to the struct page_counter and accidently
increased its size.  Let's move the failcnt field which is v1-only field
to the same cacheline of usage to reduce the size of struct page_counter.

Link: https://lkml.kernel.org/r/20250228075808.207484-4-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/page_counter.h |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/include/linux/page_counter.h~page_counter-reduce-struct-page_counter-size
+++ a/include/linux/page_counter.h
@@ -9,10 +9,12 @@
 
 struct page_counter {
 	/*
-	 * Make sure 'usage' does not share cacheline with any other field. The
-	 * memcg->memory.usage is a hot member of struct mem_cgroup.
+	 * Make sure 'usage' does not share cacheline with any other field in
+	 * v2. The memcg->memory.usage is a hot member of struct mem_cgroup.
 	 */
 	atomic_long_t usage;
+	unsigned long failcnt; /* v1-only field */
+
 	CACHELINE_PADDING(_pad1_);
 
 	/* effective memory.min and memory.min usage tracking */
@@ -28,7 +30,6 @@ struct page_counter {
 	unsigned long watermark;
 	/* Latest cg2 reset watermark */
 	unsigned long local_watermark;
-	unsigned long failcnt; /* v1-only field */
 
 	/* Keep all the read most fields in a separete cacheline. */
 	CACHELINE_PADDING(_pad2_);
_

Patches currently in -mm which might be from shakeel.butt@linux.dev are

memcg-add-hierarchical-effective-limits-for-v2.patch
memcg-avoid-refill_stock-for-root-memcg.patch
memcg-move-do_memsw_account-to-config_memcg_v1.patch