On Mon 24-08-20 10:52:02, Qian Cai wrote:

On Thu, Aug 20, 2020 at 10:58:50AM -0400, Qian Cai wrote:

quoted

On Tue, Aug 11, 2020 at 07:10:27PM +0800, Alex Shi wrote:

quoted

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 <redacted>
Acked-by: Michal Hocko <mhocko@suse.com>

This will trigger,

Andrew, Stephen, can you drop this series for now? I did manage to trigger this
warning on all arches, powerpc, x86 and arm64 (below).

Yes, I do agree. See http://lkml.kernel.org/r/20200824151013.GB3415@dhcp22.suse.cz
-- 
Michal Hocko
SUSE Labs