Rusty says:

 Actually, the #ifdef around that function is wrong:

 #if defined(CONFIG_NUMA) || defined(CONFIG_HOTPLUG_CPU)
 /* If dest_cpu is allowed for this process, migrate us to it. */
 void migrate_to_cpu(int dest_cpu)

 We don't use this for HOTPLUG_CPU, but we call __migrate_task()
 directly.

 ie. #ifdef CONFIG_NUMA is sufficient.



---

 kernel/sched.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff -puN kernel/sched.c~migrate_to_cpu-dependency-fix kernel/sched.c
--- 25/kernel/sched.c~migrate_to_cpu-dependency-fix	2004-02-19 01:40:05.000000000 -0800
+++ 25-akpm/kernel/sched.c	2004-02-19 01:40:05.000000000 -0800
@@ -1114,8 +1114,10 @@ enum idle_type
 
 #ifdef CONFIG_SMP
 
-#if defined(CONFIG_NUMA) || defined(CONFIG_HOTPLUG_CPU)
-/* If dest_cpu is allowed for this process, migrate us to it. */
+#ifdef CONFIG_NUMA
+/*
+ * If dest_cpu is allowed for this process, migrate us to it.
+ */
 void migrate_to_cpu(int dest_cpu)
 {
 	runqueue_t *rq;
@@ -1145,9 +1147,7 @@ void migrate_to_cpu(int dest_cpu)
 out:
 	task_rq_unlock(rq, &flags);
 }
-#endif /* CONFIG_NUMA || CONFIG_HOTPLUG_CPU */
 
-#ifdef CONFIG_NUMA
 /*
  * Find the least loaded CPU.  Slightly favor the current CPU by
  * setting its runqueue length as the minimum to start.

_