在 2020/8/5 下午8:28, Alex Shi 写道:
> The last patch has a problem on define. this version could fix it.
>
> BTW, I see some !memcg happens when MEMCG compilered but disabled by
> cgroup_disable
>
>
> [ 94.657666] ---[ end trace f1f34bfc3b32ed2f ]---
> [ 95.138995] anon flags: 0x5005b48008000d(locked|uptodate|dirty|swapbacked)
> [ 95.146220] raw: 005005b48008000d dead000000000100 dead000000000122
> ffff8897c7c76ad1
> [ 95.154549] raw: 0000000000000022 0000000000000000 0000000200000000
> 0000000000000000
> [ 95.162876] page dumped because: VM_WARN_ON_ONCE_PAGE(!memcg)
>
>
The following patch may helpful.
>From 8bfb26a2e37e08dc61d20212bcfa5812a367ba94 Mon Sep 17 00:00:00 2001
From: Alex Shi <[email protected]>
Date: Wed, 5 Aug 2020 20:32:12 +0800
Subject: [PATCH] mm/memcg: don't try charge swap if memcg disabled
If we disabled memcg by cgroup_disable=memory, the swap charges are
still called. Let's return from the funcs earlier and keep WARN_ON
monitor.
Signed-off-by: Alex Shi <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
mm/memcontrol.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cb07a48d53aa..65f2b42d25af 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -7163,6 +7163,9 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t
entry)
VM_BUG_ON_PAGE(PageLRU(page), page);
VM_BUG_ON_PAGE(page_count(page), page);
+ if (mem_cgroup_disabled())
+ return;
+
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
return;
@@ -7228,6 +7231,9 @@ int mem_cgroup_try_charge_swap(struct page *page,
swp_entry_t entry)
struct mem_cgroup *memcg;
unsigned short oldid;
+ if (mem_cgroup_disabled())
+ return 0;
+
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
return 0;
--
1.8.3.1
