From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758706Ab2AMSPT (ORCPT ); Fri, 13 Jan 2012 13:15:19 -0500 Received: from mail-we0-f174.google.com ([74.125.82.174]:58301 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758669Ab2AMSPO (ORCPT ); Fri, 13 Jan 2012 13:15:14 -0500 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Glauber Costa , Cgroups , "Kirill A. Shutemov" , Daniel J Walsh , "Daniel P. Berrange" , KAMEZAWA Hiroyuki , Max Kellermann , Mandeep Singh Baines , Paul Menage , Li Zefan , Johannes Weiner , Aditya Kali , Oleg Nesterov , Kay Sievers , Tim Hockin , Tejun Heo , Andrew Morton Subject: [PATCH 2/8] cgroups: new resource counter inheritance API Date: Fri, 13 Jan 2012 19:13:48 +0100 Message-Id: <1326478441-3048-5-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1326478441-3048-1-git-send-email-fweisbec@gmail.com> References: <1326478441-3048-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Provide an API to inherit a counter value from a parent. This can be useful to implement cgroup.clone_children on a resource counter. Still the resources of the children are limited by those of the parent, so this is only to provide a default setting behaviour when clone_children is set. Signed-off-by: Frederic Weisbecker Cc: Paul Menage Cc: Li Zefan Cc: Johannes Weiner Cc: Aditya Kali Cc: Oleg Nesterov Cc: Kay Sievers Cc: Tim Hockin Cc: Tejun Heo Acked-by: Kirill A. Shutemov Signed-off-by: Andrew Morton --- include/linux/res_counter.h | 2 ++ kernel/res_counter.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+), 0 deletions(-) diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 1b3fe05..109d118 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -84,6 +84,8 @@ int res_counter_write(struct res_counter *counter, int member, void res_counter_write_u64(struct res_counter *counter, int member, u64 val); +void res_counter_inherit(struct res_counter *counter, int member); + /* * the field descriptors. one for each member of res_counter */ diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 58ae85e..016b4d4 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -201,3 +201,21 @@ int res_counter_write(struct res_counter *counter, int member, return 0; } + +/* + * Simple inheritance implementation to get the same value + * than a parent. However this doesn't enforce the child value + * to be always below the one of the parent. But the child is + * subject to its parent limitation anyway. + */ +void res_counter_inherit(struct res_counter *counter, int member) +{ + struct res_counter *parent; + unsigned long long val; + + parent = counter->parent; + if (parent) { + val = res_counter_read_u64(parent, member); + res_counter_write_u64(counter, member, val); + } +} -- 1.7.5.4