From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753027Ab1IFAOV (ORCPT ); Mon, 5 Sep 2011 20:14:21 -0400 Received: from mail-vx0-f174.google.com ([209.85.220.174]:53143 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752998Ab1IFAN6 (ORCPT ); Mon, 5 Sep 2011 20:13:58 -0400 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Paul Menage , Li Zefan , Johannes Weiner , Aditya Kali , Oleg Nesterov , Andrew Morton , Kay Sievers , Tim Hockin , Tejun Heo Subject: [PATCH 05/12] cgroups: Ability to stop res charge propagation on bounded ancestor Date: Tue, 6 Sep 2011 02:12:59 +0200 Message-Id: <1315267986-28937-6-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1315267986-28937-1-git-send-email-fweisbec@gmail.com> References: <1315267986-28937-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Moving a task from a cgroup to another may require to substract its resource charge from the old cgroup and add it to the new one. For this to happen, the uncharge/charge propagation can just stop when we reach the common ancestor for the two cgroups. Further the performance reasons, we also want to avoid to temporarily overload the common ancestors with a non-accurate resource counter usage if we charge first the new cgroup and uncharge the old one thereafter. This is going to be a requirement for the coming max number of task subsystem. To solve this, provide a pair of new API that can charge/uncharge a resource counter until we reach a given ancestor. Signed-off-by: Frederic Weisbecker Acked-by: Paul Menage Cc: Li Zefan Cc: Johannes Weiner Cc: Aditya Kali Cc: Oleg Nesterov Cc: Andrew Morton Cc: Kay Sievers Cc: Tim Hockin Cc: Tejun Heo --- include/linux/res_counter.h | 19 ++++++++++++++++--- kernel/res_counter.c | 13 ++++++++----- 2 files changed, 24 insertions(+), 8 deletions(-) diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 109d118..95e7756 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -117,8 +117,16 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent); int __must_check res_counter_charge_locked(struct res_counter *counter, unsigned long val); -int __must_check res_counter_charge(struct res_counter *counter, - unsigned long val, struct res_counter **limit_fail_at); +int __must_check res_counter_charge_until(struct res_counter *counter, + struct res_counter *limit, + unsigned long val, + struct res_counter **limit_fail_at); +static inline int __must_check +res_counter_charge(struct res_counter *counter, unsigned long val, + struct res_counter **limit_fail_at) +{ + return res_counter_charge_until(counter, NULL, val, limit_fail_at); +} /* * uncharge - tell that some portion of the resource is released @@ -131,7 +139,12 @@ int __must_check res_counter_charge(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 *limit, + unsigned long val); +static inline void res_counter_uncharge(struct res_counter *counter, unsigned long val) +{ + res_counter_uncharge_until(counter, NULL, val); +} /** * res_counter_margin - calculate chargeable space of a counter diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 1349115..1185c86 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -35,8 +35,9 @@ int res_counter_charge_locked(struct res_counter *counter, unsigned long val) return 0; } -int res_counter_charge(struct res_counter *counter, unsigned long val, - struct res_counter **limit_fail_at) +int res_counter_charge_until(struct res_counter *counter, + struct res_counter *limit, unsigned long val, + struct res_counter **limit_fail_at) { int ret; unsigned long flags; @@ -44,7 +45,7 @@ int res_counter_charge(struct res_counter *counter, unsigned long val, *limit_fail_at = NULL; local_irq_save(flags); - for (c = counter; c != NULL; c = c->parent) { + for (c = counter; c != limit; c = c->parent) { spin_lock(&c->lock); ret = res_counter_charge_locked(c, val); spin_unlock(&c->lock); @@ -74,13 +75,15 @@ void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val) counter->usage -= val; } -void res_counter_uncharge(struct res_counter *counter, unsigned long val) +void res_counter_uncharge_until(struct res_counter *counter, + struct res_counter *limit, + unsigned long val) { unsigned long flags; struct res_counter *c; local_irq_save(flags); - for (c = counter; c != NULL; c = c->parent) { + for (c = counter; c != limit; c = c->parent) { spin_lock(&c->lock); res_counter_uncharge_locked(c, val); spin_unlock(&c->lock); -- 1.7.5.4