memcgroups: add a document describing the resource counter abstraction

The resource counter is supposed to facilitate the resource accounting of
arbitrary resource (and it already does this for memory controller).

However, it is about to be used in other resources controllers (swap, kernel
memory, networking, etc), so provide a doc describing how to work with it.
This will eliminate all the possible future duplications in the appropriate
controllers' docs.

Fixed errors pointed out by Randy.

[[email protected]: fix documentation tpyo]
Signed-off-by: Pavel Emelyanov <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Li Zefan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions