@@ -14,4 +14,18 @@
static inline void leave_mm(int cpu) { }
#endif
+/*
+ * CPUs that are capable of running user task @p. Must contain at least one
+ * active CPU. It is assumed that the kernel can run on all CPUs, so calling
+ * this for a kernel thread is pointless.
+ *
+ * By default, we assume a sane, homogeneous system.
+ */
+#ifndef task_cpu_possible_mask
+# define task_cpu_possible_mask(p) cpu_possible_mask
+# define task_cpu_possible(cpu, p) true
+#else
+# define task_cpu_possible(cpu, p) cpumask_test_cpu((cpu), task_cpu_possible_mask(p))
+#endif
+
#endif
@@ -1814,7 +1814,7 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
/* Non kernel threads are not allowed during either online or offline. */
if (!(p->flags & PF_KTHREAD))
- return cpu_active(cpu);
+ return cpu_active(cpu) && task_cpu_possible(cpu, p);
/* KTHREAD_IS_PER_CPU is always allowed. */
if (kthread_is_per_cpu(p))
@@ -2792,10 +2792,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
*
* More yuck to audit.
*/
- do_set_cpus_allowed(p, cpu_possible_mask);
+ do_set_cpus_allowed(p, task_cpu_possible_mask(p));
state = fail;
break;
-
case fail:
BUG();
break;