| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.19 054/123] cpuset: initialize effective masks when clone_children is enabled | Date | Tue, 24 Mar 2015 16:46:03 +0100 |
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3.19-stable review patch. If anyone has any objections, please let me know.
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From: Zefan Li <lizefan@huawei.com>
commit 790317e1b266c776765a4bdcedefea706ff0fada upstream.
If clone_children is enabled, effective masks won't be initialized due to the bug:
# mount -t cgroup -o cpuset xxx /mnt # echo 1 > cgroup.clone_children # mkdir /mnt/tmp # cat /mnt/tmp/ # cat cpuset.effective_cpus
# cat cpuset.cpus 0-15
And then this cpuset won't constrain the tasks in it.
Either the bug or the fix has no effect on unified hierarchy, as there's no clone_chidren flag there any more.
Reported-by: Christian Brauner <christianvanbrauner@gmail.com> Reported-by: Serge Hallyn <serge.hallyn@ubuntu.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 | 2 ++ 1 file changed, 2 insertions(+)
--- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1992,7 +1992,9 @@ static int cpuset_css_online(struct cgro spin_lock_irq(&callback_lock); cs->mems_allowed = parent->mems_allowed; + cs->effective_mems = parent->mems_allowed; cpumask_copy(cs->cpus_allowed, parent->cpus_allowed); + cpumask_copy(cs->effective_cpus, parent->cpus_allowed); spin_unlock_irq(&callback_lock); out_unlock: mutex_unlock(&cpuset_mutex);
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