From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762741AbbA3SzB (ORCPT ); Fri, 30 Jan 2015 13:55:01 -0500 Received: from g2t2354.austin.hp.com ([15.217.128.53]:51819 "EHLO g2t2354.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820AbbA3Sy7 (ORCPT ); Fri, 30 Jan 2015 13:54:59 -0500 Message-ID: <1422644094.3365.7.camel@j-VirtualBox> Subject: [PATCH v2] cpuset: Fix cpuset sched_relax_domain_level From: Jason Low To: Tejun Heo , Li Zefan , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, aswin@hp.com, scott.norton@hp.com, chegu_vinod@hp.com, Jason Low , stable@vger.kernel.org Date: Fri, 30 Jan 2015 10:54:54 -0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The cpuset.sched_relax_domain_level can control how far we do immediate load balancing on a system. However, it was found on recent kernels that echo'ing a value into cpuset.sched_relax_domain_level did not reduce any immediate load balancing. The reason this occurred was because the update_domain_attr_tree() traversal did not update for the "top_cpuset". This resulted in nothing being changed when modifying the sched_relax_domain_level parameter. This patch is able to address that problem by having update_domain_attr_tree() allow updates for the root in the cpuset traversal. Fixes: fc560a26acce ("cpuset: replace cpuset->stack_list with cpuset_for_each_descendant_pre()") Cc: # 3.9+ Signed-off-by: Jason Low --- kernel/cpuset.c | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 64b257f..b589e57 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -548,9 +548,6 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr, rcu_read_lock(); cpuset_for_each_descendant_pre(cp, pos_css, root_cs) { - if (cp == root_cs) - continue; - /* skip the whole subtree if @cp doesn't have any CPU */ if (cpumask_empty(cp->cpus_allowed)) { pos_css = css_rightmost_descendant(pos_css); -- 1.7.2.5