| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 36/79] cpuset: Fix cpuset sched_relax_domain_level | Date | Tue, 24 Mar 2015 16:45:47 +0100 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Jason Low <jason.low2@hp.com>
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 <jason.low2@hp.com> Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Tested-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/cpuset.c | 3 --- 1 file changed, 3 deletions(-)
--- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -503,9 +503,6 @@ static void update_domain_attr_tree(stru 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);
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