Re: [PATCH v3 5/9] memcg: use css_get/put when charging/uncharging kmem

Li Zefan
2013-06-14T01:18:09Z

>> static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
>> {
>> + /*
>> + * We need to call css_get() first, because memcg_uncharge_kmem()
>> + * will call css_put() if it sees the memcg is dead.
>> + */
>> + smb_wmb();
>> if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags))
>> set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags);
>
> I do not feel strongly about that but maybe open coding this in
> mem_cgroup_css_offline would be even better. There is only single caller
> and there is smaller chance somebody will use the function incorrectly
> later on.
>
> So I leave the decision on you because this doesn't matter much.
>

Yeah, it should go away soon. I'll post a patch after this patchset gets
merged into -mm tree and then we can discuss there.