+ memcg-use-proper-type-for-mod_memcg_state.patch added to mm-unstable branch

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

The patch titled
     Subject: memcg: use proper type for mod_memcg_state
has been added to the -mm mm-unstable branch.  Its filename is
     memcg-use-proper-type-for-mod_memcg_state.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memcg-use-proper-type-for-mod_memcg_state.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: Shakeel Butt <shakeel.butt@linux.dev>
Subject: memcg: use proper type for mod_memcg_state
Date: Fri, 26 Apr 2024 17:37:32 -0700

The memcg stats update functions can take arbitrary integer but the only
input which make sense is enum memcg_stat_item and we don't want these
functions to be called with arbitrary integer, so replace the parameter
type with enum memcg_stat_item and compiler will be able to warn if memcg
stat update functions are called with incorrect index value.

Link: https://lkml.kernel.org/r/20240427003733.3898961-7-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 <roman.gushchin@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memcontrol.h |   13 +++++++------
 mm/memcontrol.c            |    3 ++-
 2 files changed, 9 insertions(+), 7 deletions(-)

--- a/include/linux/memcontrol.h~memcg-use-proper-type-for-mod_memcg_state
+++ a/include/linux/memcontrol.h
@@ -974,7 +974,8 @@ void mem_cgroup_print_oom_group(struct m
 void folio_memcg_lock(struct folio *folio);
 void folio_memcg_unlock(struct folio *folio);
 
-void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val);
+void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item  idx,
+		       int val);
 
 /* try to stablize folio_memcg() for all the pages in a memcg */
 static inline bool mem_cgroup_trylock_pages(struct mem_cgroup *memcg)
@@ -995,7 +996,7 @@ static inline void mem_cgroup_unlock_pag
 
 /* idx can be of type enum memcg_stat_item or node_stat_item */
 static inline void mod_memcg_state(struct mem_cgroup *memcg,
-				   int idx, int val)
+				   enum memcg_stat_item idx, int val)
 {
 	unsigned long flags;
 
@@ -1005,7 +1006,7 @@ static inline void mod_memcg_state(struc
 }
 
 static inline void mod_memcg_page_state(struct page *page,
-					int idx, int val)
+					enum memcg_stat_item idx, int val)
 {
 	struct mem_cgroup *memcg;
 
@@ -1491,19 +1492,19 @@ static inline void mem_cgroup_print_oom_
 }
 
 static inline void __mod_memcg_state(struct mem_cgroup *memcg,
-				     int idx,
+				     enum memcg_stat_item idx,
 				     int nr)
 {
 }
 
 static inline void mod_memcg_state(struct mem_cgroup *memcg,
-				   int idx,
+				   enum memcg_stat_item idx,
 				   int nr)
 {
 }
 
 static inline void mod_memcg_page_state(struct page *page,
-					int idx, int val)
+					enum memcg_stat_item idx, int val)
 {
 }
 
--- a/mm/memcontrol.c~memcg-use-proper-type-for-mod_memcg_state
+++ a/mm/memcontrol.c
@@ -960,7 +960,8 @@ static int memcg_state_val_in_pages(int
  * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
  * @val: delta to add to the counter, can be negative
  */
-void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val)
+void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
+		       int val)
 {
 	int i = memcg_stats_index(idx);
 
_

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

memcg-simple-cleanup-of-stats-update-functions.patch
memcg-reduce-memory-size-of-mem_cgroup_events_index.patch
memcg-dynamically-allocate-lruvec_stats.patch
memcg-reduce-memory-for-the-lruvec-and-memcg-stats.patch
memcg-cleanup-__mod_memcg_lruvec_state.patch
memcg-pr_warn_once-for-unexpected-events-and-stats.patch
memcg-use-proper-type-for-mod_memcg_state.patch
mm-cleanup-workingset_nodes-in-workingset.patch