Re: [PATCH v20 01/20] mm/memcg: warning on !memcg after readahead page charged

[Johannes Weiner]

On Thu, Oct 29, 2020 at 06:44:46PM +0800, Alex Shi wrote:
> Add VM_WARN_ON_ONCE_PAGE() macro.
> 
> Since readahead page is charged on memcg too, in theory we don't have to
> check this exception now. Before safely remove them all, add a warning
> for the unexpected !memcg.
> 
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: cgroups@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>