Re: [PATCH v4 2/5] mm: memcontrol: directly access page->memcg_data in mm/page_alloc.c

[Johannes Weiner]

On Thu, Mar 18, 2021 at 07:06:55PM +0800, Muchun Song wrote:
> The page_memcg() is not suitable for use by page_expected_state() and
> page_bad_reason(). Because it can BUG_ON() for the slab pages when
> CONFIG_DEBUG_VM is enabled. As neither lru, nor kmem, nor slab page
> should have anything left in there by the time the page is freed, what
> we care about is whether the value of page->memcg_data is 0. So just
> directly access page->memcg_data here.
> 
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>