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 --- Documentation/cgroups/resource_counter.txt | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation') diff --git a/Documentation/cgroups/resource_counter.txt b/Documentation/cgroups/resource_counter.txt index f3c4ec3626a2..0c4a344e78fa 100644 --- a/Documentation/cgroups/resource_counter.txt +++ b/Documentation/cgroups/resource_counter.txt @@ -92,6 +92,14 @@ to work with it. The _locked routines imply that the res_counter->lock is taken. + f. void res_counter_uncharge_until + (struct res_counter *rc, struct res_counter *top, + unsinged long val) + + Almost same as res_cunter_uncharge() but propagation of uncharge + stops when rc == top. This is useful when kill a res_coutner in + child cgroup. + 2.1 Other accounting routines There are more routines that may help you with common needs, like -- cgit v1.2.3-59-g8ed1b