在 2020/8/5 下午9:02, Alex Shi 写道: > > > 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. Any comments for the 2 patches? Thanks Alex > > 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; > >
