From 2bb2ba9d51a8044a71a29608d2c4ef8f5b2d57a2 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 29 May 2012 15:07:03 -0700 Subject: 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 Signed-off-by: KAMEZAWA Hiroyuki Cc: Aneesh Kumar K.V Cc: Michal Hocko Cc: Johannes Weiner Cc: Ying Han Cc: Glauber Costa Reviewed-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/res_counter.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index fb201896a8b0..5de7a146ead9 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -135,6 +135,9 @@ int __must_check res_counter_charge_nofail(struct res_counter *counter, void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val); void res_counter_uncharge(struct res_counter *counter, unsigned long val); +void res_counter_uncharge_until(struct res_counter *counter, + struct res_counter *top, + unsigned long val); /** * res_counter_margin - calculate chargeable space of a counter * @cnt: the counter -- cgit v1.2.3