1 files changed, 52 insertions, 14 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 7e75a41bd508..b5cb469d2545 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1324,9 +1324,10 @@ static int fmeter_getrate(struct fmeter *fmp)
 static cpumask_var_t cpus_attach;
 
 /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys *ss,
-                             struct cgroup *cont, struct task_struct *tsk)
+static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+                             struct task_struct *tsk, bool threadgroup)
 {
+        int ret;
         struct cpuset *cs = cgroup_cs(cont);
 
         if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
@@ -1343,18 +1344,51 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
         if (tsk->flags & PF_THREAD_BOUND)
                 return -EINVAL;
 
-        return security_task_setscheduler(tsk, 0, NULL);
+        ret = security_task_setscheduler(tsk, 0, NULL);
+        if (ret)
+                return ret;
+        if (threadgroup) {
+                struct task_struct *c;
+
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+                        ret = security_task_setscheduler(c, 0, NULL);
+                        if (ret) {
+                                rcu_read_unlock();
+                                return ret;
+                        }
+                }
+                rcu_read_unlock();
+        }
+        return 0;
+}
+
+static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to,
+                               struct cpuset *cs)
+{
+        int err;
+        /*
+         * can_attach beforehand should guarantee that this doesn't fail.
+         * TODO: have a better way to handle failure here
+         */
+        err = set_cpus_allowed_ptr(tsk, cpus_attach);
+        WARN_ON_ONCE(err);
+
+        task_lock(tsk);
+        cpuset_change_task_nodemask(tsk, to);
+        task_unlock(tsk);
+        cpuset_update_task_spread_flag(cs, tsk);
+
 }
 
-static void cpuset_attach(struct cgroup_subsys *ss,
-                          struct cgroup *cont, struct cgroup *oldcont,
-                          struct task_struct *tsk)
+static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+                          struct cgroup *oldcont, struct task_struct *tsk,
+                          bool threadgroup)
 {
         nodemask_t from, to;
         struct mm_struct *mm;
         struct cpuset *cs = cgroup_cs(cont);
         struct cpuset *oldcs = cgroup_cs(oldcont);
-        int err;
 
         if (cs == &top_cpuset) {
                 cpumask_copy(cpus_attach, cpu_possible_mask);
@@ -1363,15 +1397,19 @@ static void cpuset_attach(struct cgroup_subsys *ss,
                 guarantee_online_cpus(cs, cpus_attach);
                 guarantee_online_mems(cs, &to);
         }
-        err = set_cpus_allowed_ptr(tsk, cpus_attach);
-        if (err)
-                return;
 
-        task_lock(tsk);
-        cpuset_change_task_nodemask(tsk, &to);
-        task_unlock(tsk);
-        cpuset_update_task_spread_flag(cs, tsk);
+        /* do per-task migration stuff possibly for each in the threadgroup */
+        cpuset_attach_task(tsk, &to, cs);
+        if (threadgroup) {
+                struct task_struct *c;
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
+                        cpuset_attach_task(c, &to, cs);
+                }
+                rcu_read_unlock();
+        }
 
+        /* change mm; only needs to be done once even if threadgroup */
         from = oldcs->mems_allowed;
         to = cs->mems_allowed;
         mm = get_task_mm(tsk);