Re: [PATCH -v2] memcg: don't do cleanup manually if mem_cgroup_css_online() fails

[Li Zefan <lizefan@huawei.com>]

>>> But memcg_update_cache_sizes calls memcg_kmem_clear_activated on the
>>> error path.
>>>
>>
>> But memcg_kmem_mark_dead() checks the ACCOUNT flag not the ACCOUNTED flag.
>> Am I missing something?
>>
> 
> Dang. You are right! Glauber, is there any reason why
> memcg_kmem_mark_dead checks only KMEM_ACCOUNTED_ACTIVE rather than
> KMEM_ACCOUNTED_MASK?
> 
> This all is very confusing to say the least.
> 
> Anyway, this all means that Li's first patch is correct. I am not sure I
> like it though. I think that the refcount cleanup should be done as
> close to where it has been taken as possible otherwise we will end up in
> this "chase the nasty details" again and again. There are definitely two
> bugs here. The one introduced by e4715f01 and the other one introduced
> even earlier (I haven't checked that history yet). I think we should do
> something like the 2 follow up patches but if you guys think that the smaller
> patch from Li is more appropriate then I will not block it.
> 

Or we can queue my patch for 3.9, and then see if we want to change the
tear down process, and if yes we make the change for 3.10.