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 <alex.shi@xxxxxxxxxxxxxxxxx> 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 <alex.shi@xxxxxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: cgroups@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- 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
