1 files changed, 43 insertions, 100 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1b6f615be587..64b3f791bbe5 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -265,17 +265,6 @@ static DEFINE_MUTEX(cpuset_mutex);
 static DEFINE_MUTEX(callback_mutex);
 
 /*
- * cpuset_buffer_lock protects both the cpuset_name and cpuset_nodelist
- * buffers.  They are statically allocated to prevent using excess stack
- * when calling cpuset_print_task_mems_allowed().
- */
-#define CPUSET_NAME_LEN		(128)
-#define	CPUSET_NODELIST_LEN	(256)
-static char cpuset_name[CPUSET_NAME_LEN];
-static char cpuset_nodelist[CPUSET_NODELIST_LEN];
-static DEFINE_SPINLOCK(cpuset_buffer_lock);
-
-/*
  * CPU / memory hotplug is handled asynchronously.
  */
 static struct workqueue_struct *cpuset_propagate_hotplug_wq;
@@ -780,25 +769,26 @@ static void rebuild_sched_domains_locked(void)
 	lockdep_assert_held(&cpuset_mutex);
 	get_online_cpus();
 
+	/*
+	 * We have raced with CPU hotplug. Don't do anything to avoid
+	 * passing doms with offlined cpu to partition_sched_domains().
+	 * Anyways, hotplug work item will rebuild sched domains.
+	 */
+	if (!cpumask_equal(top_cpuset.cpus_allowed, cpu_active_mask))
+		goto out;
+
 	/* Generate domain masks and attrs */
 	ndoms = generate_sched_domains(&doms, &attr);
 
 	/* Have scheduler rebuild the domains */
 	partition_sched_domains(ndoms, doms, attr);
-
+out:
 	put_online_cpus();
 }
 #else /* !CONFIG_SMP */
 static void rebuild_sched_domains_locked(void)
 {
 }
-
-static int generate_sched_domains(cpumask_var_t **domains,
-			struct sched_domain_attr **attributes)
-{
-	*domains = NULL;
-	return 1;
-}
 #endif /* CONFIG_SMP */
 
 void rebuild_sched_domains(void)
@@ -1388,16 +1378,16 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 
 	cgroup_taskset_for_each(task, cgrp, tset) {
 		/*
-		 * Kthreads bound to specific cpus cannot be moved to a new
-		 * cpuset; we cannot change their cpu affinity and
-		 * isolating such threads by their set of allowed nodes is
-		 * unnecessary.  Thus, cpusets are not applicable for such
-		 * threads.  This prevents checking for success of
-		 * set_cpus_allowed_ptr() on all attached tasks before
-		 * cpus_allowed may be changed.
+		 * Kthreads which disallow setaffinity shouldn't be moved
+		 * to a new cpuset; we don't want to change their cpu
+		 * affinity and isolating such threads by their set of
+		 * allowed nodes is unnecessary.  Thus, cpusets are not
+		 * applicable for such threads.  This prevents checking for
+		 * success of set_cpus_allowed_ptr() on all attached tasks
+		 * before cpus_allowed may be changed.
 		 */
 		ret = -EINVAL;
-		if (task->flags & PF_THREAD_BOUND)
+		if (task->flags & PF_NO_SETAFFINITY)
 			goto out_unlock;
 		ret = security_task_setscheduler(task);
 		if (ret)
@@ -2005,50 +1995,6 @@ int __init cpuset_init(void)
 	return 0;
 }
 
-/**
- * cpuset_do_move_task - move a given task to another cpuset
- * @tsk: pointer to task_struct the task to move
- * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
- *
- * Called by cgroup_scan_tasks() for each task in a cgroup.
- * Return nonzero to stop the walk through the tasks.
- */
-static void cpuset_do_move_task(struct task_struct *tsk,
-				struct cgroup_scanner *scan)
-{
-	struct cgroup *new_cgroup = scan->data;
-
-	cgroup_lock();
-	cgroup_attach_task(new_cgroup, tsk);
-	cgroup_unlock();
-}
-
-/**
- * move_member_tasks_to_cpuset - move tasks from one cpuset to another
- * @from: cpuset in which the tasks currently reside
- * @to: cpuset to which the tasks will be moved
- *
- * Called with cpuset_mutex held
- * callback_mutex must not be held, as cpuset_attach() will take it.
- *
- * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
- * calling callback functions for each.
- */
-static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to)
-{
-	struct cgroup_scanner scan;
-
-	scan.cg = from->css.cgroup;
-	scan.test_task = NULL; /* select all tasks in cgroup */
-	scan.process_task = cpuset_do_move_task;
-	scan.heap = NULL;
-	scan.data = to->css.cgroup;
-
-	if (cgroup_scan_tasks(&scan))
-		printk(KERN_ERR "move_member_tasks_to_cpuset: "
-				"cgroup_scan_tasks failed\n");
-}
-
 /*
  * If CPU and/or memory hotplug handlers, below, unplug any CPUs
  * or memory nodes, we need to walk over the cpuset hierarchy,
@@ -2069,7 +2015,12 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
 			nodes_empty(parent->mems_allowed))
 		parent = parent_cs(parent);
 
-	move_member_tasks_to_cpuset(cs, parent);
+	if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) {
+		rcu_read_lock();
+		printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset %s\n",
+		       cgroup_name(cs->css.cgroup));
+		rcu_read_unlock();
+	}
 }
 
 /**
@@ -2222,17 +2173,8 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
 	flush_workqueue(cpuset_propagate_hotplug_wq);
 
 	/* rebuild sched domains if cpus_allowed has changed */
-	if (cpus_updated) {
-		struct sched_domain_attr *attr;
-		cpumask_var_t *doms;
-		int ndoms;
-
-		mutex_lock(&cpuset_mutex);
-		ndoms = generate_sched_domains(&doms, &attr);
-		mutex_unlock(&cpuset_mutex);
-
-		partition_sched_domains(ndoms, doms, attr);
-	}
+	if (cpus_updated)
+		rebuild_sched_domains();
 }
 
 void cpuset_update_active_cpus(bool cpu_online)
@@ -2251,7 +2193,6 @@ void cpuset_update_active_cpus(bool cpu_online)
 	schedule_work(&cpuset_hotplug_work);
 }
 
-#ifdef CONFIG_MEMORY_HOTPLUG
 /*
  * Keep top_cpuset.mems_allowed tracking node_states[N_MEMORY].
  * Call this routine anytime after node_states[N_MEMORY] changes.
@@ -2263,20 +2204,23 @@ static int cpuset_track_online_nodes(struct notifier_block *self,
 	schedule_work(&cpuset_hotplug_work);
 	return NOTIFY_OK;
 }
-#endif
+
+static struct notifier_block cpuset_track_online_nodes_nb = {
+	.notifier_call = cpuset_track_online_nodes,
+	.priority = 10,		/* ??! */
+};
 
 /**
  * cpuset_init_smp - initialize cpus_allowed
  *
  * Description: Finish top cpuset after cpu, node maps are initialized
- **/
-
+ */
 void __init cpuset_init_smp(void)
 {
 	cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask);
 	top_cpuset.mems_allowed = node_states[N_MEMORY];
 
-	hotplug_memory_notifier(cpuset_track_online_nodes, 10);
+	register_hotmemory_notifier(&cpuset_track_online_nodes_nb);
 
 	cpuset_propagate_hotplug_wq =
 		alloc_ordered_workqueue("cpuset_hotplug", 0);
@@ -2592,6 +2536,8 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
 	return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed);
 }
 
+#define CPUSET_NODELIST_LEN	(256)
+
 /**
  * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed
  * @task: pointer to task_struct of some task.
@@ -2602,25 +2548,22 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
  */
 void cpuset_print_task_mems_allowed(struct task_struct *tsk)
 {
-	struct dentry *dentry;
+	 /* Statically allocated to prevent using excess stack. */
+	static char cpuset_nodelist[CPUSET_NODELIST_LEN];
+	static DEFINE_SPINLOCK(cpuset_buffer_lock);
 
-	dentry = task_cs(tsk)->css.cgroup->dentry;
-	spin_lock(&cpuset_buffer_lock);
+	struct cgroup *cgrp = task_cs(tsk)->css.cgroup;
 
-	if (!dentry) {
-		strcpy(cpuset_name, "/");
-	} else {
-		spin_lock(&dentry->d_lock);
-		strlcpy(cpuset_name, (const char *)dentry->d_name.name,
-			CPUSET_NAME_LEN);
-		spin_unlock(&dentry->d_lock);
-	}
+	rcu_read_lock();
+	spin_lock(&cpuset_buffer_lock);
 
 	nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN,
 			   tsk->mems_allowed);
 	printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n",
-	       tsk->comm, cpuset_name, cpuset_nodelist);
+	       tsk->comm, cgroup_name(cgrp), cpuset_nodelist);
+
 	spin_unlock(&cpuset_buffer_lock);
+	rcu_read_unlock();
 }
 
 /*