mm: memcg: move memcg_account_kmem() to memcontrol-v1.c

Patch series "mm: memcg: put cgroup v1-specific memcg data under
CONFIG_MEMCG_V1".

This patchset puts all cgroup v1's members of struct mem_cgroup, struct
mem_cgroup_per_node and struct task_struct under the CONFIG_MEMCG_V1
config option.  If cgroup v1 support is not required (and it's true for
many cgroup users these days), it allows to save a bit of memory and
compile out some code, some of which is on relatively hot paths.  It also
structures the code a bit better by grouping cgroup v1-specific stuff in
one place.


This patch (of 9):

memcg_account_kmem() consists of a trivial statistics change via
mod_memcg_state() call and a relatively large memcg1-specific part.

Let's factor out the mod_memcg_state() call and move the rest into the
mm/memcontrol-v1.c file.  Also rename memcg_account_kmem() into
memcg1_account_kmem() for consistency.

Link: https://lkml.kernel.org/r/20240628210317.272856-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20240628210317.272856-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index a3ea4a5e8c96..34579085559f 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -2913,6 +2913,18 @@ struct cftype memsw_files[] = {
 	{ },	/* terminate */
 };
 
+#ifdef CONFIG_MEMCG_KMEM
+void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages)
+{
+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
+		if (nr_pages > 0)
+			page_counter_charge(&memcg->kmem, nr_pages);
+		else
+			page_counter_uncharge(&memcg->kmem, -nr_pages);
+	}
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
 static int __init memcg1_init(void)
 {
 	int node;