sched: Add CONFIG_SCHED_HMP Kconfig option

Add a compile-time flag to enable or disable scheduler features for
HMP (heterogenous multi-processor) systems. Main feature deals with
optimizing task placement for best power/performance tradeoff.

Also extend features currently dependent on CONFIG_SCHED_FREQ_INPUT to
be enabled for CONFIG_HMP as well.

Change-Id: I03b3942709a80cc19f7b934a8089e1d84c14d72d
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
[rameezmustafa@codeaurora.org]: Port to msm-3.18]
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
[joonwoop@codeaurora.org: fixed minor ifdefry conflict.]
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>

include/linux/sched.h

@@ -1203,7 +1203,7 @@ struct sched_avg {
 	u64 last_update_time, load_sum;
 	u32 util_sum, period_contrib;
 	unsigned long load_avg, util_avg;
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 	u32 runnable_avg_sum_scaled;
 #endif
 };
@@ -1427,7 +1427,7 @@ struct task_struct {
 	const struct sched_class *sched_class;
 	struct sched_entity se;
 	struct sched_rt_entity rt;
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 	struct ravg ravg;
 #endif
 #ifdef CONFIG_CGROUP_SCHED

init/Kconfig

@@ -1153,6 +1153,15 @@ config CGROUP_WRITEBACK
 
 endif # CGROUPS
 
+config SCHED_HMP
+	bool "Scheduler support for heterogenous multi-processor systems"
+	depends on SMP && FAIR_GROUP_SCHED
+	help
+	  This feature will let the scheduler optimize task placement on
+	  systems made of heterogeneous cpus i.e cpus that differ either
+	  in their instructions per-cycle capability or the maximum
+	  frequency they can attain.
+
 config CHECKPOINT_RESTORE
 	bool "Checkpoint/restore support" if EXPERT
 	select PROC_CHILDREN

kernel/sched/core.c

@@ -1746,7 +1746,7 @@ static inline void ttwu_activate(struct rq *rq, struct task_struct *p, int en_fl
 		wq_worker_waking_up(p, cpu_of(rq));
 }
 
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 
 /* Window size (in ns) */
 __read_mostly unsigned int sched_ravg_window = 10000000;
@@ -1893,7 +1893,7 @@ void update_task_ravg(struct task_struct *p, struct rq *rq, int update_sum)
 	p->ravg.mark_start = wallclock;
 }
 
-#endif	/* CONFIG_SCHED_FREQ_INPUT */
+#endif	/* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 /*
  * Mark the task runnable and perform wakeup-preemption.
@@ -7573,7 +7573,8 @@ void __init sched_init_smp(void)
 #endif /* CONFIG_SMP */
 
 
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
+
 /*
  * Maximum possible frequency across all cpus. Task demand and cpu
  * capacity (cpu_power) metrics are scaled in reference to it.
@@ -7660,7 +7661,7 @@ static int register_sched_callback(void)
  */
 core_initcall(register_sched_callback);
 
-#endif /* CONFIG_SCHED_FREQ_INPUT */
+#endif	/* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 int in_sched_functions(unsigned long addr)
 {
@@ -7799,7 +7800,7 @@ void __init sched_init(void)
 		rq->online = 0;
 		rq->idle_stamp = 0;
 		rq->avg_idle = 2*sysctl_sched_migration_cost;
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 		rq->cur_freq = 1;
 		rq->max_freq = 1;
 		rq->min_freq = 1;

kernel/sched/fair.c

@@ -2911,7 +2911,7 @@ static inline int idle_balance(struct rq *rq)
 
 #endif /* CONFIG_SMP */
 
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 
 static inline unsigned int task_load(struct task_struct *p)
 {
@@ -2974,7 +2974,7 @@ static inline void decay_scaled_stat(struct sched_avg *sa, u64 periods)
 			   periods);
 }
 
-#else  /* CONFIG_SCHED_FREQ_INPUT */
+#else  /* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 static inline void
 add_to_scaled_stat(int cpu, struct sched_avg *sa, u64 delta)
@@ -2985,7 +2985,7 @@ static inline void decay_scaled_stat(struct sched_avg *sa, u64 periods)
 {
 }
 
-#endif /* CONFIG_SCHED_FREQ_INPUT */
+#endif /* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {

kernel/sched/sched.h

@@ -643,7 +643,7 @@ struct rq {
 	u64 max_idle_balance_cost;
 #endif
 
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 	/*
 	 * max_freq = user or thermal defined maximum
 	 * max_possible_freq = maximum supported by hardware
@@ -917,7 +917,7 @@ static inline void sched_ttwu_pending(void) { }
 #include "stats.h"
 #include "auto_group.h"
 
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 
 extern unsigned int sched_ravg_window;
 extern unsigned int max_possible_freq;
@@ -938,7 +938,7 @@ dec_cumulative_runnable_avg(struct rq *rq, struct task_struct *p)
 	BUG_ON((s64)rq->cumulative_runnable_avg < 0);
 }
 
-#else	/* CONFIG_SCHED_FREQ_INPUT */
+#else	/* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 static inline int pct_task_load(struct task_struct *p) { return 0; }
 
@@ -954,7 +954,7 @@ dec_cumulative_runnable_avg(struct rq *rq, struct task_struct *p)
 
 static inline void init_new_task_load(struct task_struct *p) { }
 
-#endif	/* CONFIG_SCHED_FREQ_INPUT */
+#endif	/* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 #ifdef CONFIG_CGROUP_SCHED
 
@@ -1289,15 +1289,15 @@ struct sched_class {
 #endif
 };
 
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 extern void
 update_task_ravg(struct task_struct *p, struct rq *rq, int update_sum);
-#else	/* CONFIG_SCHED_FREQ_INPUT */
+#else	/* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 static inline void
 update_task_ravg(struct task_struct *p, struct rq *rq, int update_sum)
 {
 }
-#endif	/* CONFIG_SCHED_FREQ_INPUT */
+#endif	/* CONFIG_SCHED_FREQ_INPUT || CONFIG_SCHED_HMP */
 
 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
 {

kernel/sysctl.c

@@ -292,7 +292,7 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
-#ifdef CONFIG_SCHED_FREQ_INPUT
+#if defined(CONFIG_SCHED_FREQ_INPUT) || defined(CONFIG_SCHED_HMP)
 	{
 		.procname       = "sched_window_stats_policy",
 		.data           = &sysctl_sched_window_stats_policy,