mm: memcontrol: introduce obj_cgroup_{un}charge_pages

We know that the unit of slab object charging is bytes, the unit of kmem
page charging is PAGE_SIZE.  If we want to reuse obj_cgroup APIs to
charge the kmem pages, we should pass PAGE_SIZE (as third parameter) to
obj_cgroup_charge().  Because the size is already PAGE_SIZE, we can skip
touch the objcg stock.  And obj_cgroup_{un}charge_pages() are introduced
to charge in units of page level.

In the latter patch, we also can reuse those two helpers to charge or
uncharge a number of kernel pages to a object cgroup.  This is just a
code movement without any functional changes.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muchun Song <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Xiongchun Duan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions