Re: [PATCH] mm/memcg: set memcg when split pages

[Michal Hocko]

On Tue 02-03-21 10:37:13, Zi Yan wrote:
[...]
> I have a question on copy_page_memcg above. By reading __memcg_kmem_charge_page
> and __memcg_kmem_uncharge_page, it seems to me that every single page requires
> a css_get(&memcg->css) at charge time and a css_put(&memcg->css) at uncharge time.
> But your copy_page_memcg does not do css_get for split subpages. Will it cause
> memcg->css underflow when subpages are uncharged?

yes, well spotted. I have completely missed that. This will also discard
my comment on testing the memcg.


-- 
Michal Hocko
SUSE Labs