On 1/30/22 01:33, Mike Rapoport wrote:
On Sat, Jan 29, 2022 at 03:53:15PM -0500, Waiman Long wrote:
It was found that a number of offlined memcgs were not freed because
they were pinned by some charged pages that were present. Even "echo
1 > /proc/sys/vm/drop_caches" wasn't able to free those pages. These
offlined but not freed memcgs tend to increase in number over time with
the side effect that percpu memory consumption as shown in /proc/meminfo
also increases over time.
In order to find out more information about those pages that pin
offlined memcgs, the page_owner feature is extended to dump memory
cgroup information especially whether the cgroup is offlined or not.
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
mm/page_owner.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 28dac73e0542..8dc5cd0fa227 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -10,6 +10,7 @@
#include <linux/migrate.h>
#include <linux/stackdepot.h>
#include <linux/seq_file.h>
+#include <linux/memcontrol.h>
#include <linux/sched/clock.h>
#include "internal.h"
@@ -331,6 +332,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
depot_stack_handle_t handle)
{
int ret, pageblock_mt, page_mt;
+ unsigned long __maybe_unused memcg_data;
char *kbuf;
count = min_t(size_t, count, PAGE_SIZE);
@@ -365,6 +367,35 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
migrate_reason_names[page_owner->last_migrate_reason]);
}
+#ifdef CONFIG_MEMCG
Can we put all this along with the declaration of memcg_data in a helper
function please?
Sure. Will post another version with that change.
Cheers,
Longman
