Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 157fb9b2b186bb4922bd7c8322a81c823ce69fed..e3ed0ecee7c7a47c2b8c85e3717b3606343c30aa 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1265,29 +1265,59 @@ EXPORT_SYMBOL_GPL(kick_process);
  */
 static int select_fallback_rq(int cpu, struct task_struct *p)
 {
-       int dest_cpu;
        const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+       enum { cpuset, possible, fail } state = cpuset;
+       int dest_cpu;
 
        /* Look for allowed, online CPU in same node. */
-       for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
+       for_each_cpu_mask(dest_cpu, *nodemask) {
+               if (!cpu_online(dest_cpu))
+                       continue;
+               if (!cpu_active(dest_cpu))
+                       continue;
                if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
                        return dest_cpu;
+       }
 
-       /* Any allowed, online CPU? */
-       dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask);
-       if (dest_cpu < nr_cpu_ids)
-               return dest_cpu;
+       for (;;) {
+               /* Any allowed, online CPU? */
+               for_each_cpu_mask(dest_cpu, *tsk_cpus_allowed(p)) {
+                       if (!cpu_online(dest_cpu))
+                               continue;
+                       if (!cpu_active(dest_cpu))
+                               continue;
+                       goto out;
+               }
 
-       /* No more Mr. Nice Guy. */
-       dest_cpu = cpuset_cpus_allowed_fallback(p);
-       /*
-        * Don't tell them about moving exiting tasks or
-        * kernel threads (both mm NULL), since they never
-        * leave kernel.
-        */
-       if (p->mm && printk_ratelimit()) {
-               printk_sched("process %d (%s) no longer affine to cpu%d\n",
-                               task_pid_nr(p), p->comm, cpu);
+               switch (state) {
+               case cpuset:
+                       /* No more Mr. Nice Guy. */
+                       cpuset_cpus_allowed_fallback(p);
+                       state = possible;
+                       break;
+
+               case possible:
+                       do_set_cpus_allowed(p, cpu_possible_mask);
+                       state = fail;
+                       break;
+
+               case fail:
+                       BUG();
+                       break;
+               }
+       }
+
+out:
+       if (state != cpuset) {
+               /*
+                * Don't tell them about moving exiting tasks or
+                * kernel threads (both mm NULL), since they never
+                * leave kernel.
+                */
+               if (p->mm && printk_ratelimit()) {
+                       printk_sched("process %d (%s) no longer affine to cpu%d\n",
+                                       task_pid_nr(p), p->comm, cpu);
+               }
        }
 
        return dest_cpu;