From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756253AbbDGN2I (ORCPT ); Tue, 7 Apr 2015 09:28:08 -0400 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:54399 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754060AbbDGMwG (ORCPT ); Tue, 7 Apr 2015 08:52:06 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jason Low , Zefan Li , Tejun Heo , Jiri Slaby Subject: [PATCH 3.12 043/155] cpuset: Fix cpuset sched_relax_domain_level Date: Tue, 7 Apr 2015 14:50:12 +0200 Message-Id: X-Mailer: git-send-email 2.3.4 In-Reply-To: <9a548862b8a26cbccc14f2c6c9c3688813d8d14b.1428411003.git.jslaby@suse.cz> References: <9a548862b8a26cbccc14f2c6c9c3688813d8d14b.1428411003.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Low 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 283cb41f426b723a0255702b761b0fc5d1b53a81 upstream. 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()") Signed-off-by: Jason Low Signed-off-by: Zefan Li Signed-off-by: Tejun Heo Tested-by: Serge Hallyn Signed-off-by: Jiri Slaby --- kernel/cpuset.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index c8289138cad4..b5f0faa4bfbd 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -503,9 +503,6 @@ 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); -- 2.3.4