rescounters: add res_counter_uncharge_until()

When killing a res_counter which is a child of other counter, we need to
do

	res_counter_uncharge(child, xxx)
	res_counter_charge(parent, xxx)

This is not atomic and wastes CPU.  This patch adds
res_counter_uncharge_until().  This function's uncharge propagates to
ancestors until specified res_counter.

	res_counter_uncharge_until(child, parent, xxx)

Now the operation is atomic and efficient.

Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Ying Han <[email protected]>
Cc: Glauber Costa <[email protected]>
Reviewed-by: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions