Commit bbe5ab81 authored by Waiman Long's avatar Waiman Long Committed by Tejun Heo
Browse files

cgroup/cpuset: Simplify setsched decision check in task iteration loop of cpuset_can_attach() 



Centralize the check required to run security_task_setscheduler() in
the task iteration loop of cpuset_can_attach() outside of the loop as
it has no dependency on the characteristics of the tasks themselves.

There is no functional change.

Signed-off-by: default avatarWaiman Long <longman@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 4c56a8ac

kernel/cgroup/cpuset.c

+10 −9
Original line number Diff line number Diff line
@@ -2988,7 +2988,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) 
	struct cgroup_subsys_state *css;

	struct cpuset *cs, *oldcs;

	struct task_struct *task;

	bool cpus_updated, mems_updated;

	bool setsched_check;

	int ret;



	/* used later by cpuset_attach() */
@@ -3003,20 +3003,21 @@ static int cpuset_can_attach(struct cgroup_taskset *tset) 
	if (ret)

		goto out_unlock;



	cpus_updated = !cpumask_equal(cs->effective_cpus, oldcs->effective_cpus);

	mems_updated = !nodes_equal(cs->effective_mems, oldcs->effective_mems);

	/*

	 * Skip rights over task setsched check in v2 when nothing changes,

	 * migration permission derives from hierarchy ownership in

	 * cgroup_procs_write_permission()).

	 */

	setsched_check = !cpuset_v2() ||

		!cpumask_equal(cs->effective_cpus, oldcs->effective_cpus) ||

		!nodes_equal(cs->effective_mems, oldcs->effective_mems);



	cgroup_taskset_for_each(task, css, tset) {

		ret = task_can_attach(task);

		if (ret)

			goto out_unlock;



		/*

		 * Skip rights over task check in v2 when nothing changes,

		 * migration permission derives from hierarchy ownership in

		 * cgroup_procs_write_permission()).

		 */

		if (!cpuset_v2() || (cpus_updated || mems_updated)) {

		if (setsched_check) {

			ret = security_task_setscheduler(task);

			if (ret)

				goto out_unlock;