---

yaml
---
r: 350341
b: refs/heads/master
c: 4e4c9a1
h: refs/heads/master
i:
  350339: c428a0d
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ae8086ce15fdab2b57599d7a3242a114ba4b8597
+refs/heads/master: 4e4c9a140fc2ecf5e086922ccd2022bdabe509b6

trunk/kernel/cpuset.c

@@ -1395,15 +1395,6 @@ static int fmeter_getrate(struct fmeter *fmp)
 	return val;
 }
 
-/*
- * Protected by cgroup_lock. The nodemasks must be stored globally because
- * dynamically allocating them is not allowed in can_attach, and they must
- * persist until attach.
- */
-static cpumask_var_t cpus_attach;
-static nodemask_t cpuset_attach_nodemask_from;
-static nodemask_t cpuset_attach_nodemask_to;
-
 /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
 static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
@@ -1430,26 +1421,36 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 			return ret;
 	}
 
-	/* prepare for attach */
-	if (cs == &top_cpuset)
-		cpumask_copy(cpus_attach, cpu_possible_mask);
-	else
-		guarantee_online_cpus(cs, cpus_attach);
-
-	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
-
 	return 0;
 }
 
+/*
+ * Protected by cgroup_mutex.  cpus_attach is used only by cpuset_attach()
+ * but we can't allocate it dynamically there.  Define it global and
+ * allocate from cpuset_init().
+ */
+static cpumask_var_t cpus_attach;
+
 static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
+	/* static bufs protected by cgroup_mutex */
+	static nodemask_t cpuset_attach_nodemask_from;
+	static nodemask_t cpuset_attach_nodemask_to;
 	struct mm_struct *mm;
 	struct task_struct *task;
 	struct task_struct *leader = cgroup_taskset_first(tset);
 	struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
 	struct cpuset *cs = cgroup_cs(cgrp);
 	struct cpuset *oldcs = cgroup_cs(oldcgrp);
 
+	/* prepare for attach */
+	if (cs == &top_cpuset)
+		cpumask_copy(cpus_attach, cpu_possible_mask);
+	else
+		guarantee_online_cpus(cs, cpus_attach);
+
+	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
+
 	cgroup_taskset_for_each(task, cgrp, tset) {
 		/*
 		 * can_attach beforehand should guarantee that this doesn't