On Fri, Aug 21, 2020 at 8:01 AM Roman Gushchin [off-list ref] wrote:

From: Johannes Weiner <hannes@cmpxchg.org>

Support nesting of memalloc_use_memcg() to be able to use
from an interrupt context.

Make memalloc_use_memcg() return the old memcg and convert existing
users to a stacking model. Delete the unused memalloc_unuse_memcg().

Roman: I've rephrased the original commit log, because it was
focused on the accounting problem related to loop devices. I made
it less specific, so it can work for bpf too. Also rebased to the
current state of the mm tree.

The original patch can be found here:
https://lkml.org/lkml/2020/5/28/806

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Roman Gushchin <redacted>

Reviewed-by: Shakeel Butt <redacted>