5 files changed, 106 insertions, 6 deletions

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 753afbca549f..4b5bc452176c 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1891,7 +1891,7 @@ static int cgroup_reconfigure(struct fs_context *fc)
  */
 static bool use_task_css_set_links __read_mostly;
 
-static void cgroup_enable_task_cg_lists(void)
+void cgroup_enable_task_cg_lists(void)
 {
         struct task_struct *p, *g;
 
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 5aa37531ce76..846cbdb68566 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -45,6 +45,7 @@
 #include <linux/proc_fs.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
+#include <linux/sched/deadline.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/task.h>
 #include <linux/seq_file.h>
@@ -894,6 +895,67 @@ done:
         return ndoms;
 }
 
+static void update_tasks_root_domain(struct cpuset *cs)
+{
+        struct css_task_iter it;
+        struct task_struct *task;
+
+        css_task_iter_start(&cs->css, 0, &it);
+
+        while ((task = css_task_iter_next(&it)))
+                dl_add_task_root_domain(task);
+
+        css_task_iter_end(&it);
+}
+
+static void rebuild_root_domains(void)
+{
+        struct cpuset *cs = NULL;
+        struct cgroup_subsys_state *pos_css;
+
+        lockdep_assert_held(&cpuset_mutex);
+        lockdep_assert_cpus_held();
+        lockdep_assert_held(&sched_domains_mutex);
+
+        cgroup_enable_task_cg_lists();
+
+        rcu_read_lock();
+
+        /*
+         * Clear default root domain DL accounting, it will be computed again
+         * if a task belongs to it.
+         */
+        dl_clear_root_domain(&def_root_domain);
+
+        cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) {
+
+                if (cpumask_empty(cs->effective_cpus)) {
+                        pos_css = css_rightmost_descendant(pos_css);
+                        continue;
+                }
+
+                css_get(&cs->css);
+
+                rcu_read_unlock();
+
+                update_tasks_root_domain(cs);
+
+                rcu_read_lock();
+                css_put(&cs->css);
+        }
+        rcu_read_unlock();
+}
+
+static void
+partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
+                                    struct sched_domain_attr *dattr_new)
+{
+        mutex_lock(&sched_domains_mutex);
+        partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
+        rebuild_root_domains();
+        mutex_unlock(&sched_domains_mutex);
+}
+
 /*
  * Rebuild scheduler domains.
  *
@@ -931,7 +993,7 @@ static void rebuild_sched_domains_locked(void)
         ndoms = generate_sched_domains(&doms, &attr);
 
         /* Have scheduler rebuild the domains */
-        partition_sched_domains(ndoms, doms, attr);
+        partition_and_rebuild_sched_domains(ndoms, doms, attr);
 out:
         put_online_cpus();
 }
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index ef5b9f6b1d42..0f9d2180be23 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2283,6 +2283,36 @@ void __init init_sched_dl_class(void)
                                         GFP_KERNEL, cpu_to_node(i));
 }
 
+void dl_add_task_root_domain(struct task_struct *p)
+{
+        struct rq_flags rf;
+        struct rq *rq;
+        struct dl_bw *dl_b;
+
+        rq = task_rq_lock(p, &rf);
+        if (!dl_task(p))
+                goto unlock;
+
+        dl_b = &rq->rd->dl_bw;
+        raw_spin_lock(&dl_b->lock);
+
+        __dl_add(dl_b, p->dl.dl_bw, cpumask_weight(rq->rd->span));
+
+        raw_spin_unlock(&dl_b->lock);
+
+unlock:
+        task_rq_unlock(rq, p, &rf);
+}
+
+void dl_clear_root_domain(struct root_domain *rd)
+{
+        unsigned long flags;
+
+        raw_spin_lock_irqsave(&rd->dl_bw.lock, flags);
+        rd->dl_bw.total_bw = 0;
+        raw_spin_unlock_irqrestore(&rd->dl_bw.lock, flags);
+}
+
 #endif /* CONFIG_SMP */
 
 static void switched_from_dl(struct rq *rq, struct task_struct *p)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 16126efd14ed..7583faddba33 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -778,9 +778,6 @@ struct root_domain {
         struct perf_domain __rcu *pd;
 };
 
-extern struct root_domain def_root_domain;
-extern struct mutex sched_domains_mutex;
-
 extern void init_defrootdomain(void);
 extern int sched_init_domains(const struct cpumask *cpu_map);
 extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 5a174ae6ecf3..8f83e8e3ea9a 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2203,8 +2203,19 @@ void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[],
         for (i = 0; i < ndoms_cur; i++) {
                 for (j = 0; j < n && !new_topology; j++) {
                         if (cpumask_equal(doms_cur[i], doms_new[j]) &&
-                            dattrs_equal(dattr_cur, i, dattr_new, j))
+                            dattrs_equal(dattr_cur, i, dattr_new, j)) {
+                                struct root_domain *rd;
+
+                                /*
+                                 * This domain won't be destroyed and as such
+                                 * its dl_bw->total_bw needs to be cleared.  It
+                                 * will be recomputed in function
+                                 * update_tasks_root_domain().
+                                 */
+                                rd = cpu_rq(cpumask_any(doms_cur[i]))->rd;
+                                dl_clear_root_domain(rd);
                                 goto match1;
+                        }
                 }
                 /* No match - a current sched domain not in new doms_new[] */
                 detach_destroy_domains(doms_cur[i]);