Re: [PATCH] mm/memcg: update page struct member in comments

[Roman Gushchin <guro@fb.com>]

On Fri, Nov 06, 2020 at 07:33:33PM +0800, Alex Shi wrote:
> The page->mem_cgroup member is replaced by memcg_data, and add a helper
> page_memcg() for it. Need to update comments to avoid confusing.

Hi Alex,

thank you for bringing it in!
I definitely missed those.

> 
> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org> 
> Cc: Michal Hocko <mhocko@kernel.org> 
> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> 
> Cc: Andrew Morton <akpm@linux-foundation.org> 
> Cc: cgroups@vger.kernel.org 
> Cc: linux-mm@kvack.org 
> Cc: linux-kernel@vger.kernel.org 
> ---
>  mm/memcontrol.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index b2aa3b73ab82..8a8debea34fc 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1310,7 +1310,7 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
>   * @page: the page
>   * @pgdat: pgdat of the page
>   *
> - * This function relies on page->mem_cgroup being stable - see the
> + * This function relies on page_memcg(page) being stable - see the
>   * access rules in commit_charge().

There are "page and memcg binding" and "page's memcg" used in similar cases,
I think it's more obvious than "page_memcg(page) being stable".

Maybe it helps to address Ira's comment.

Anyway, please feel free to add:
Acked-by: Roman Gushchin <guro@fb.com>

Thanks!