sched/headers: Split hotplug CPU interfaces out of <linux/sched.h> into <linux/sched/hotplug.h>

Split the CPU hotplug scheduler APIs out of the common header.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

include/linux/sched.h

@@ -196,15 +196,6 @@ extern void cpu_init (void);
 extern void trap_init(void);
 extern void update_process_times(int user);
 extern void scheduler_tick(void);
-extern int sched_cpu_starting(unsigned int cpu);
-extern int sched_cpu_activate(unsigned int cpu);
-extern int sched_cpu_deactivate(unsigned int cpu);
-
-#ifdef CONFIG_HOTPLUG_CPU
-extern int sched_cpu_dying(unsigned int cpu);
-#else
-# define sched_cpu_dying	NULL
-#endif
 
 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
 extern signed long schedule_timeout(signed long timeout);
@@ -1498,12 +1489,6 @@ extern void sched_exec(void);
 #define sched_exec()   {}
 #endif
 
-#ifdef CONFIG_HOTPLUG_CPU
-extern void idle_task_exit(void);
-#else
-static inline void idle_task_exit(void) {}
-#endif
-
 extern int yield_to(struct task_struct *p, bool preempt);
 extern void set_user_nice(struct task_struct *p, long nice);
 extern int task_prio(const struct task_struct *p);

include/linux/sched/hotplug.h

@@ -3,4 +3,24 @@
 
 #include <linux/sched.h>
 
+/*
+ * Scheduler interfaces for hotplug CPU support:
+ */
+
+extern int sched_cpu_starting(unsigned int cpu);
+extern int sched_cpu_activate(unsigned int cpu);
+extern int sched_cpu_deactivate(unsigned int cpu);
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern int sched_cpu_dying(unsigned int cpu);
+#else
+# define sched_cpu_dying	NULL
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern void idle_task_exit(void);
+#else
+static inline void idle_task_exit(void) {}
+#endif
+
 #endif /* _LINUX_SCHED_HOTPLUG_H */