[PATCH 28/53] sched/headers: Move the NOHZ APIs from to

Ingo Molnar
2017-02-08T18:47:21Z

There's a number of NOHZ/dyntics related functionality in <linux/sched.h>,
but only a handful of timer files are making use of them.

Move them into their own header. This better documents these APIs
and unclutters <linux/sched.h>.

Cc: Linus 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: Ingo Molnar <mingo@kernel.org>
---
include/linux/sched.h | 35 -----------------------------------
include/linux/sched/nohz.h | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+), 35 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b4f0d9888d8c..c83424b1e1ac 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -46,14 +46,6 @@ struct nameidata;
struct signal_struct;
struct sighand_struct;

-#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
-extern void cpu_load_update_nohz_start(void);
-extern void cpu_load_update_nohz_stop(void);
-#else
-static inline void cpu_load_update_nohz_start(void) { }
-static inline void cpu_load_update_nohz_stop(void) { }
-#endif
-
extern void dump_cpu_task(int cpu);

struct seq_file;
@@ -204,15 +196,6 @@ extern cpumask_var_t cpu_isolated_map;

extern int runqueue_is_locked(int cpu);

-#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
-extern void nohz_balance_enter_idle(int cpu);
-extern void set_cpu_sd_state_idle(void);
-extern int get_nohz_timer_target(void);
-#else
-static inline void nohz_balance_enter_idle(int cpu) { }
-static inline void set_cpu_sd_state_idle(void) { }
-#endif
-
/*
* Only dump TASK_* tasks. (0 for all tasks)
*/
@@ -1531,14 +1514,6 @@ static inline int set_cpus_allowed_ptr(struct task_struct *p,
}
#endif

-#ifdef CONFIG_NO_HZ_COMMON
-void calc_load_enter_idle(void);
-void calc_load_exit_idle(void);
-#else
-static inline void calc_load_enter_idle(void) { }
-static inline void calc_load_exit_idle(void) { }
-#endif /* CONFIG_NO_HZ_COMMON */
-
#ifndef cpu_relax_yield
#define cpu_relax_yield() cpu_relax()
#endif
@@ -1559,16 +1534,6 @@ extern void idle_task_exit(void);
static inline void idle_task_exit(void) {}
#endif

-#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
-extern void wake_up_nohz_cpu(int cpu);
-#else
-static inline void wake_up_nohz_cpu(int cpu) { }
-#endif
-
-#ifdef CONFIG_NO_HZ_FULL
-extern u64 scheduler_tick_max_deferment(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);
diff --git a/include/linux/sched/nohz.h b/include/linux/sched/nohz.h
index fe6caf0dab10..9471f0736a3a 100644
--- a/include/linux/sched/nohz.h
+++ b/include/linux/sched/nohz.h
@@ -3,4 +3,43 @@

#include <linux/sched.h>

+/*
+ * This is the interface between the scheduler and nohz/dyntics:
+ */
+
+#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
+extern void cpu_load_update_nohz_start(void);
+extern void cpu_load_update_nohz_stop(void);
+#else
+static inline void cpu_load_update_nohz_start(void) { }
+static inline void cpu_load_update_nohz_stop(void) { }
+#endif
+
+#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
+extern void nohz_balance_enter_idle(int cpu);
+extern void set_cpu_sd_state_idle(void);
+extern int get_nohz_timer_target(void);
+#else
+static inline void nohz_balance_enter_idle(int cpu) { }
+static inline void set_cpu_sd_state_idle(void) { }
+#endif
+
+#ifdef CONFIG_NO_HZ_COMMON
+void calc_load_enter_idle(void);
+void calc_load_exit_idle(void);
+#else
+static inline void calc_load_enter_idle(void) { }
+static inline void calc_load_exit_idle(void) { }
+#endif /* CONFIG_NO_HZ_COMMON */
+
+#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
+extern void wake_up_nohz_cpu(int cpu);
+#else
+static inline void wake_up_nohz_cpu(int cpu) { }
+#endif
+
+#ifdef CONFIG_NO_HZ_FULL
+extern u64 scheduler_tick_max_deferment(void);
+#endif
+
#endif /* _LINUX_SCHED_NOHZ_H */
--
2.7.4