From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Weisbecker 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> References: <1326478441-3048-1-git-send-email-fweisbec@gmail.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=JcOskuHfAOFJQF/dOIKwthPp6WJBE8LMtUrdCZMzPkI=; b=N5yipzgOgYkSwUISnDJwGzl7+qIqlIdjuOMbwBbCX1GRAQje10Er/YU80qpryXRohr ZiI7rwwMu9yUWSY8N6TQLXKPJB9yfp9gbyjl3jBEtnH7frhyrsfJ+XMEZXhxCiZNGZGU l33OR5hbB92u1x0dH7l3TFjOj8mrzrcFUImbU= In-Reply-To: <1326478441-3048-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 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