cpuset: fix a warning when clearing configured masks in old hierarchy (79063bff) · Commits · 戴 / test

When we clear cpuset.cpus, cpuset.effective_cpus won't be cleared: # mount -t cgroup -o cpuset xxx /mnt # mkdir /mnt/tmp # echo 0 > /mnt/tmp/cpuset.cpus # echo > /mnt/tmp/cpuset.cpus # cat cpuset.cpus # cat cpuset.effective_cpus 0-15 And a kernel warning in update_cpumasks_hier() is triggered: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 4028 at kernel/cpuset.c:894 update_cpumasks_hier+0x471/0x650() Cc: <stable@vger.kernel.org> # 3.17+ Signed-off-by:

Zefan Li <lizefan@huawei.com> Signed-off-by:

Tejun Heo <tj@kernel.org> Tested-by:

Serge Hallyn <serge.hallyn@canonical.com>

kernel/cpuset.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -873,7 +873,7 @@ static void update_cpumasks_hier(struct cpuset cs, struct cpumask new_cpus)
		* If it becomes empty, inherit the effective mask of the
		* parent, which is guaranteed to have some CPUs.
		*/
		if (cpumask_empty(new_cpus))
		if (cgroup_on_dfl(cp->css.cgroup) && cpumask_empty(new_cpus))
		cpumask_copy(new_cpus, parent->effective_cpus);

		/* Skip the whole subtree if the cpumask remains the same. */
		@@ -1129,7 +1129,7 @@ static void update_nodemasks_hier(struct cpuset cs, nodemask_t new_mems)
		* If it becomes empty, inherit the effective mask of the
		* parent, which is guaranteed to have some MEMs.
		*/
		if (nodes_empty(*new_mems))
		if (cgroup_on_dfl(cp->css.cgroup) && nodes_empty(*new_mems))
		*new_mems = parent->effective_mems;

		/* Skip the whole subtree if the nodemask remains the same. */

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