Re: [PATCH 4/5] mm: memcontrol: move remote memcg charging APIs to CONFIG_MEMCG_KMEM

On Mon, Mar 01, 2021 at 07:43:27PM -0800, Shakeel Butt wrote:

On Mon, Mar 1, 2021 at 5:16 PM Roman Gushchin [off-list ref] wrote:

quoted

On Mon, Mar 01, 2021 at 02:22:26PM +0800, Muchun Song wrote:

quoted

The remote memcg charing APIs is a mechanism to charge kernel memory
to a given memcg. So we can move the infrastructure to the scope of
the CONFIG_MEMCG_KMEM.

This is not a good idea, because there is nothing kmem-specific
in the idea of remote charging, and we definitely will see cases
when user memory is charged to the process different from the current.

Indeed and which remind me: what happened to the "Charge loop device
i/o to issuing cgroup" series? That series was doing remote charging
for user pages.

Yeah, this is exactly what I minded. We're using it internally, and as I
remember there were no obstacles to upstream it too.
I'll ping Dan when after the merge window.

Thanks!