Re: [PATCH v2] cpuset: Fix cpuset sched_relax_domain_level
From: Zefan Li <hidden>
Date: 2015-01-31 00:31:29
Also in:
lkml, stable
On 2015/1/31 2:54, Jason Low wrote:
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: <redacted> # 3.9+
Signed-off-by: Jason Low <redacted>Acked-by: Zefan Li <redacted>
quoted hunk ↗ jump to hunk
--- 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);