[Devel] [PATCH RHEL COMMIT] mm/memcg: enable memory.high for cgroup v1.

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.vz9.1.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after ark-5.14
------>
commit ec8209c1703def2334c300626d9430c1ad0d1df9
Author: Vasily Averin <vvs at virtuozzo.com>
Date:   Tue Sep 28 14:05:09 2021 +0300

    mm/memcg: enable memory.high for cgroup v1.
    
    This adds memory.high file in cgroup v1. Semantics is the
    same as for cgroup v2.
    
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
    
    (cherry picked from commit c432767aac6f77c2d8ffad588da89d0a66c29249)
    VvS: rebase to rh9
    https://jira.sw.ru/browse/PSBM-133990
    Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
---
 mm/memcontrol.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b64b4b2bdee0..9f231a39ea75 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5030,6 +5030,9 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
 static ssize_t memory_low_write(struct kernfs_open_file *of,
 				char *buf, size_t nbytes, loff_t off);
 static int memory_low_show(struct seq_file *m, void *v);
+static int memory_high_show(struct seq_file *m, void *v);
+static ssize_t memory_high_write(struct kernfs_open_file *of,
+				 char *buf, size_t nbytes, loff_t off);
 
 static struct cftype mem_cgroup_legacy_files[] = {
 	{
@@ -5067,6 +5070,12 @@ static struct cftype mem_cgroup_legacy_files[] = {
 		.write = memory_low_write,
 		.seq_show = memory_low_show,
 	},
+	{
+		.name = "high",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = memory_high_show,
+		.write = memory_high_write,
+	},
 	{
 		.name = "stat",
 		.seq_show = memcg_stat_show,