The quilt patch titled
Subject: mm: memcg: add cache line padding to mem_cgroup_per_node
has been removed from the -mm tree. Its filename was
mm-memcg-add-cache-line-padding-to-mem_cgroup_per_node.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: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Subject: mm: memcg: add cache line padding to mem_cgroup_per_node
Date: Mon, 1 Jul 2024 18:59:32 +0000
Memcg v1-specific fields serve a buffer function between read-mostly and
update often parts of the mem_cgroup_per_node structure. If
CONFIG_MEMCG_V1 is not set and these fields are not present, an explicit
cacheline padding is needed.
Link: https://lkml.kernel.org/r/20240701185932.704807-2-roman.gushchin@xxxxxxxxx
Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Suggested-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Acked-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/include/linux/memcontrol.h~mm-memcg-add-cache-line-padding-to-mem_cgroup_per_node
+++ a/include/linux/memcontrol.h
@@ -95,14 +95,16 @@ struct mem_cgroup_per_node {
#ifdef CONFIG_MEMCG_V1
/*
* Memcg-v1 only stuff in middle as buffer between read mostly fields
- * and update often fields to avoid false sharing. Once v1 stuff is
- * moved in a separate struct, an explicit padding is needed.
+ * and update often fields to avoid false sharing. If v1 stuff is
+ * not present, an explicit padding is needed.
*/
struct rb_node tree_node; /* RB tree node */
unsigned long usage_in_excess;/* Set to the value by which */
/* the soft limit is exceeded*/
bool on_tree;
+#else
+ CACHELINE_PADDING(_pad1_);
#endif
/* Fields which get updated often at the end. */
_
Patches currently in -mm which might be from roman.gushchin@xxxxxxxxx are
