diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 7230bb5..2e9b9eb 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -177,6 +177,7 @@
 #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
 #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
+void clear_tasks_mm_cpumask(int cpu);
 int cpu_down(unsigned int cpu);
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 0e6353c..0575197 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -10,6 +10,8 @@
 #include <linux/sched.h>
 #include <linux/unistd.h>
 #include <linux/cpu.h>
+#include <linux/oom.h>
+#include <linux/rcupdate.h>
 #include <linux/export.h>
 #include <linux/kthread.h>
 #include <linux/stop_machine.h>
@@ -173,6 +175,30 @@
 }
 EXPORT_SYMBOL(unregister_cpu_notifier);
 
+void clear_tasks_mm_cpumask(int cpu)
+{
+	struct task_struct *p;
+
+	/*
+	 * This function is called after the cpu is taken down and marked
+	 * offline, so its not like new tasks will ever get this cpu set in
+	 * their mm mask. -- Peter Zijlstra
+	 * Thus, we may use rcu_read_lock() here, instead of grabbing
+	 * full-fledged tasklist_lock.
+	 */
+	rcu_read_lock();
+	for_each_process(p) {
+		struct task_struct *t;
+
+		t = find_lock_task_mm(p);
+		if (!t)
+			continue;
+		cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
+		task_unlock(t);
+	}
+	rcu_read_unlock();
+}
+
 static inline void check_for_tasks(int cpu)
 {
 	struct task_struct *p;