RFC Cgroup accounting of memory tier usage

For controlling usage of a top tiered memory by a cgroup, accounting of top tier memory usage is needed. This patch set implements the following:

Patch 1 introduces interface and simple implementation to retrieve
cgroup tiered memory usage
Patch 2 introduces more efficient accounting with top tier memory page counter Patch 3 provides a sysfs interface to repot the the top tiered memory
usage.

The patchset works with Aneesh's v6 memory-tiering implementation [1]. It is a preparatory patch set before introducing features to control top tiered memory in cgroups.

I'll like to first get feedback to see if
(1) Controllng the topmost tiered memory is enough
or
(2) Multiple tiers at the top levels need to be grouped into "toptier" or
(3) There are use cases not covered by (1) and (2).

Thanks.

Tim

[1] https://lore.kernel.org/linux-mm/[email protected]/

Tim Chen (3):
mm/memory-tiers Add functions for tier memory usage in a cgroup mm/memory-tiers: Use page counter to track toptier memory usage mm/memory-tiers: Show toptier memory usage for cgroup

 include/linux/memcontrol.h   |  1 +
 include/linux/memory-tiers.h |  2 +
 mm/memcontrol.c              | 86 +++++++++++++++++++++++++++++++++++-
 mm/memory-tiers.c            |  3 +-
 4 files changed, 89 insertions(+), 3 deletions(-)

2.35.1