From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756254Ab1ILXNc (ORCPT ); Mon, 12 Sep 2011 19:13:32 -0400 Received: from mail-vw0-f52.google.com ([209.85.212.52]:45745 "EHLO mail-vw0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755960Ab1ILXMB (ORCPT ); Mon, 12 Sep 2011 19:12:01 -0400 From: Frederic Weisbecker To: Andrew Morton Cc: LKML , Frederic Weisbecker , Containers , Li Zefan , Johannes Weiner , Aditya Kali , Oleg Nesterov , Kay Sievers , Tim Hockin , Tejun Heo Subject: [PATCH 06/11] cgroups: Add res counter common ancestor searching Date: Tue, 13 Sep 2011 01:11:26 +0200 Message-Id: <1315869091-18933-7-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1315869091-18933-1-git-send-email-fweisbec@gmail.com> References: <1315869091-18933-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a new API to find the common ancestor between two resource counters. This includes the passed resource counter themselves. 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 | 3 +++ kernel/res_counter.c | 22 ++++++++++++++++++++++ 2 files changed, 25 insertions(+), 0 deletions(-) diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index de4ba29..558f39b 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -147,6 +147,9 @@ static inline void res_counter_uncharge(struct res_counter *counter, res_counter_uncharge_until(counter, NULL, val); } +struct res_counter *res_counter_common_ancestor(struct res_counter *l, + struct res_counter *r); + /** * res_counter_margin - calculate chargeable space of a counter * @cnt: the counter diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 0cc9c7e..22f07cc 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -91,6 +91,28 @@ void res_counter_uncharge_until(struct res_counter *counter, local_irq_restore(flags); } +/* + * Walk through r1 and r2 parents and try to find the closest common one + * between both. If none is found, it returns NULL. + */ +struct res_counter * +res_counter_common_ancestor(struct res_counter *r1, struct res_counter *r2) +{ + struct res_counter *iter; + + while (r1) { + iter = r2; + while (iter) { + if (iter == r1) + return iter; + iter = iter->parent; + } + + r1 = r1->parent; + } + + return NULL; +} static inline unsigned long long * res_counter_member(struct res_counter *counter, int member) -- 1.7.5.4