cacule-5.13.patch

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 68b21395a743..3f4b9c6911be 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -1088,6 +1088,10 @@ Model available). If your platform happens to meet the
 requirements for EAS but you do not want to use it, change
 this value to 0.
 
+sched_interactivity_factor (CacULE scheduler only)
+==================================================
+Sets the value *m* for interactivity score calculations. See
+Figure 1 in https://web.cs.ucdavis.edu/~roper/ecs150/ULE.pdf
 
 sched_schedstats
 ================
diff --git a/Documentation/scheduler/sched-CacULE.rst b/Documentation/scheduler/sched-CacULE.rst
new file mode 100644
index 000000000000..82b0847c468a
--- /dev/null
+++ b/Documentation/scheduler/sched-CacULE.rst
@@ -0,0 +1,76 @@
+======================================
+The CacULE Scheduler by Hamad Al Marri.
+======================================
+
+1.  Overview
+=============
+
+The CacULE CPU scheduler is based on interactivity score mechanism.
+The interactivity score is inspired by the ULE scheduler (FreeBSD
+scheduler).
+
+1.1 About CacULE Scheduler
+--------------------------
+
+  - Each CPU has its own runqueue.
+
+  - NORMAL runqueue is a linked list of sched_entities (instead of RB-Tree).
+
+  - RT and other runqueues are just the same as the CFS's.
+
+  - Wake up tasks preempt currently running tasks if its interactivity score value
+    is higher.
+
+
+1.2. Complexity
+----------------
+
+The complexity of Enqueue and Dequeue a task is O(1).
+
+The complexity of pick the next task is in O(n), where n is the number of tasks
+in a runqueue (each CPU has its own runqueue).
+
+Note: O(n) sounds scary, but usually for a machine with 4 CPUS where it is used
+for desktop or mobile jobs, the maximum number of runnable tasks might not
+exceeds 10 (at the pick next run time) - the idle tasks are excluded since they
+are dequeued when sleeping and enqueued when they wake up.
+
+
+2. The CacULE Interactivity Score
+=======================================================
+
+The interactivity score is inspired by the ULE scheduler (FreeBSD scheduler).
+For more information see: https://web.cs.ucdavis.edu/~roper/ecs150/ULE.pdf
+CacULE doesn't replace CFS with ULE, it only changes the CFS' pick next task
+mechanism to ULE's interactivity score mechanism for picking next task to run.
+
+
+2.3 sched_interactivity_factor
+=================
+Sets the value *m* for interactivity score calculations. See Figure 1 in
+https://web.cs.ucdavis.edu/~roper/ecs150/ULE.pdf
+The default value of in CacULE is 10 which means that the Maximum Interactive
+Score is 20 (since m = Maximum Interactive Score / 2).
+You can tune sched_interactivity_factor with sysctl command:
+
+	sysctl kernel.sched_interactivity_factor=50
+
+This command changes the sched_interactivity_factor from 10 to 50.
+
+
+3. Scheduling policies
+=======================
+
+CacULE some CFS, implements three scheduling policies:
+
+  - SCHED_NORMAL (traditionally called SCHED_OTHER): The scheduling
+    policy that is used for regular tasks.
+
+  - SCHED_BATCH: Does not preempt nearly as often as regular tasks
+    would, thereby allowing tasks to run longer and make better use of
+    caches but at the cost of interactivity. This is well suited for
+    batch jobs.
+
+  - SCHED_IDLE: This is even weaker than nice 19, but its not a true
+    idle timer scheduler in order to avoid to get into priority
+    inversion problems which would deadlock the machine.
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d2c881384517..0be8e440d720 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -450,10 +450,22 @@ struct sched_statistics {
 #endif
 };
 
+#ifdef CONFIG_CACULE_SCHED
+struct cacule_node {
+	struct cacule_node* 		next;
+	struct cacule_node* 		prev;
+	u64				cacule_start_time;
+	u64				vruntime;
+};
+#endif
+
 struct sched_entity {
 	/* For load-balancing: */
 	struct load_weight		load;
 	struct rb_node			run_node;
+#ifdef CONFIG_CACULE_SCHED
+	struct cacule_node		cacule_node;
+#endif
 	struct list_head		group_node;
 	unsigned int			on_rq;
 
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index db2c0f34aaaf..5a66fc5826fc 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -32,6 +32,12 @@ extern unsigned int sysctl_sched_latency;
 extern unsigned int sysctl_sched_min_granularity;
 extern unsigned int sysctl_sched_wakeup_granularity;
 
+#ifdef CONFIG_CACULE_SCHED
+extern unsigned int interactivity_factor;
+extern unsigned int interactivity_threshold;
+extern unsigned int cacule_max_lifetime;
+#endif
+
 enum sched_tunable_scaling {
 	SCHED_TUNABLESCALING_NONE,
 	SCHED_TUNABLESCALING_LOG,
diff --git a/init/Kconfig b/init/Kconfig
index a61c92066c2e..089e3bfe5dbc 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -834,6 +834,17 @@ config UCLAMP_BUCKETS_COUNT
 
 endmenu
 
+config CACULE_SCHED
+	bool "CacULE CPU scheduler"
+	default y
+	help
+	  The CacULE CPU scheduler is based on interactivity score mechanism.
+	  The interactivity score is inspired by the ULE scheduler (FreeBSD
+	  scheduler).
+
+	  If unsure, say Y here.
+
+
 #
 # For architectures that want to enable the support for NUMA-affine scheduler
 # balancing logic:
@@ -1231,6 +1242,7 @@ config SCHED_AUTOGROUP
 	select CGROUPS
 	select CGROUP_SCHED
 	select FAIR_GROUP_SCHED
+	default y
 	help
 	  This option optimizes the scheduler for common desktop workloads by
 	  automatically creating and populating task groups.  This separation
diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz
index 38ef6d06888e..865f8dbddca8 100644
--- a/kernel/Kconfig.hz
+++ b/kernel/Kconfig.hz
@@ -46,6 +46,9 @@ choice
 	 1000 Hz is the preferred choice for desktop systems and other
 	 systems requiring fast interactive responses to events.
 
+	config HZ_2000
+		bool "2000 HZ"
+
 endchoice
 
 config HZ
@@ -54,6 +57,7 @@ config HZ
 	default 250 if HZ_250
 	default 300 if HZ_300
 	default 1000 if HZ_1000
+	default 2000 if HZ_2000
 
 config SCHED_HRTICK
 	def_bool HIGH_RES_TIMERS
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5226cc26a095..8505beec4e99 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3574,6 +3574,11 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
 	p->se.prev_sum_exec_runtime	= 0;
 	p->se.nr_migrations		= 0;
 	p->se.vruntime			= 0;
+
+#ifdef CONFIG_CACULE_SCHED
+	p->se.cacule_node.vruntime	= 0;
+#endif
+
 	INIT_LIST_HEAD(&p->se.group_node);
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -3859,6 +3864,10 @@ void wake_up_new_task(struct task_struct *p)
 	update_rq_clock(rq);
 	post_init_entity_util_avg(p);
 
+#ifdef CONFIG_CACULE_SCHED
+	p->se.cacule_node.cacule_start_time = sched_clock();
+#endif
+
 	activate_task(rq, p, ENQUEUE_NOCLOCK);
 	trace_sched_wakeup_new(p);
 	check_preempt_curr(rq, p, WF_FORK);
@@ -8103,6 +8112,10 @@ void __init sched_init(void)
 	BUG_ON(&dl_sched_class + 1 != &stop_sched_class);
 #endif
 
+#ifdef CONFIG_CACULE_SCHED
+	printk(KERN_INFO "CacULE CPU scheduler v5.13 by Hamad Al Marri.");
+#endif
+
 	wait_bit_init();
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 9c882f20803e..1af3163f5b73 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -560,8 +560,11 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
 
 void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 {
-	s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
-		spread, rq0_min_vruntime, spread0;
+	s64 MIN_vruntime = -1, max_vruntime = -1,
+#if !defined(CONFIG_CACULE_SCHED)
+	min_vruntime, rq0_min_vruntime, spread0,
+#endif
+	spread;
 	struct rq *rq = cpu_rq(cpu);
 	struct sched_entity *last;
 	unsigned long flags;
@@ -582,21 +585,27 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 	last = __pick_last_entity(cfs_rq);
 	if (last)
 		max_vruntime = last->vruntime;
+#if !defined(CONFIG_CACULE_SCHED)
 	min_vruntime = cfs_rq->min_vruntime;
 	rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
+#endif
 	raw_spin_unlock_irqrestore(&rq->lock, flags);
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "MIN_vruntime",
 			SPLIT_NS(MIN_vruntime));
+#if !defined(CONFIG_CACULE_SCHED)
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "min_vruntime",
 			SPLIT_NS(min_vruntime));
+#endif
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "max_vruntime",
 			SPLIT_NS(max_vruntime));
 	spread = max_vruntime - MIN_vruntime;
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread",
 			SPLIT_NS(spread));
+#if !defined(CONFIG_CACULE_SCHED)
 	spread0 = min_vruntime - rq0_min_vruntime;
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "spread0",
 			SPLIT_NS(spread0));
+#endif
 	SEQ_printf(m, "  .%-30s: %d\n", "nr_spread_over",
 			cfs_rq->nr_spread_over);
 	SEQ_printf(m, "  .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3248e24a90b0..5bc521731064 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -19,9 +19,25 @@
  *
  *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
+ *
+ *  CacULE enhancements CPU cache and scheduler based on
+ *  Interactivity Score.
+ *  (C) 2020 Hamad Al Marri <hamad.s.almarri@gmail.com>
  */
 #include "sched.h"
 
+#ifdef CONFIG_CACULE_SCHED
+unsigned int __read_mostly cacule_max_lifetime		= 22000; // in ms
+unsigned int __read_mostly interactivity_factor		= 32768;
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+unsigned int __read_mostly interactivity_threshold	= 0;
+#else
+unsigned int __read_mostly interactivity_threshold	= 1000;
+#endif
+
+#endif
+
 /*
  * Targeted preemption latency for CPU-bound tasks:
  *
@@ -82,7 +98,11 @@ unsigned int sysctl_sched_child_runs_first __read_mostly;
 unsigned int sysctl_sched_wakeup_granularity			= 1000000UL;
 static unsigned int normalized_sysctl_sched_wakeup_granularity	= 1000000UL;
 
+#ifdef CONFIG_CACULE_SCHED
+const_debug unsigned int sysctl_sched_migration_cost	= 200000UL;
+#else
 const_debug unsigned int sysctl_sched_migration_cost	= 500000UL;
+#endif
 
 int sched_thermal_decay_shift;
 static int __init setup_sched_thermal_decay_shift(char *str)
@@ -263,6 +283,14 @@ static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight
 
 const struct sched_class fair_sched_class;
 
+
+#ifdef CONFIG_CACULE_SCHED
+static inline struct sched_entity *se_of(struct cacule_node *cn)
+{
+	return container_of(cn, struct sched_entity, cacule_node);
+}
+#endif
+
 /**************************************************************
  * CFS operations on generic schedulable entities:
  */
@@ -522,7 +550,7 @@ void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec);
 /**************************************************************
  * Scheduling class tree data structure manipulation methods:
  */
-
+#if !defined(CONFIG_CACULE_SCHED)
 static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime)
 {
 	s64 delta = (s64)(vruntime - max_vruntime);
@@ -585,7 +613,170 @@ static inline bool __entity_less(struct rb_node *a, const struct rb_node *b)
 {
 	return entity_before(__node_2_se(a), __node_2_se(b));
 }
+#endif /* CONFIG_CACULE_SCHED */
+
+#ifdef CONFIG_CACULE_SCHED
+static unsigned int
+calc_interactivity(u64 now, struct cacule_node *se)
+{
+	u64 l_se, vr_se, sleep_se = 1ULL, u64_factor_m, _2m;
+	unsigned int score_se;
+
+	/*
+	 * in case of vruntime==0, logical OR with 1 would
+	 * make sure that the least sig. bit is 1
+	 */
+	l_se		= now - se->cacule_start_time;
+	vr_se		= se->vruntime | 1;
+	u64_factor_m	= interactivity_factor;
+	_2m		= u64_factor_m << 1;
+
+	/* safety check */
+	if (likely(l_se > vr_se))
+		sleep_se = (l_se - vr_se) | 1;
+
+	if (sleep_se >= vr_se)
+		score_se = u64_factor_m / (sleep_se / vr_se);
+	else
+		score_se = _2m - (u64_factor_m / (vr_se / sleep_se));
+
+	return score_se;
+}
+
+static inline int is_interactive(struct cacule_node *cn)
+{
+	if (!interactivity_threshold || se_of(cn)->vruntime == 0)
+		return 0;
+
+	return calc_interactivity(sched_clock(), cn) < interactivity_threshold;
+}
+
+static inline int
+entity_before_cached(u64 now, unsigned int score_curr, struct cacule_node *se)
+{
+	unsigned int score_se;
+	int diff;
+
+	score_se	= calc_interactivity(now, se);
+	diff		= score_se - score_curr;
+
+	if (diff <= 0)
+		return 1;
+
+	return -1;
+}
+
+/*
+ * Does se have lower interactivity score value (i.e. interactive) than curr? If yes, return 1,
+ * otherwise return -1
+ * se is before curr if se has lower interactivity score value
+ * the lower score, the more interactive
+ */
+static inline int
+entity_before(u64 now, struct cacule_node *curr, struct cacule_node *se)
+{
+	unsigned int score_curr, score_se;
+	int diff;
+
+	score_curr	= calc_interactivity(now, curr);
+	score_se	= calc_interactivity(now, se);
+
+	diff		= score_se - score_curr;
+
+	if (diff < 0)
+		return 1;
+
+	return -1;
+}
 
+/*
+ * Enqueue an entity
+ */
+static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *_se)
+{
+	struct cacule_node *se = &(_se->cacule_node);
+	struct cacule_node *iter, *next = NULL;
+	u64 now = sched_clock();
+	unsigned int score_se = calc_interactivity(now, se);
+
+	se->next = NULL;
+	se->prev = NULL;
+
+	if (likely(cfs_rq->head)) {
+
+		// start from tail
+		iter = cfs_rq->tail;
+
+		// does se have higher IS than iter?
+		while (iter && entity_before_cached(now, score_se, iter) == -1) {
+			next = iter;
+			iter = iter->prev;
+		}
+
+		// se in tail position
+		if (iter == cfs_rq->tail) {
+			cfs_rq->tail->next	= se;
+			se->prev		= cfs_rq->tail;
+
+			cfs_rq->tail		= se;
+		}
+		// else if not head no tail, insert se after iter
+		else if (iter) {
+			se->next	= next;
+			se->prev	= iter;
+
+			iter->next	= se;
+			next->prev	= se;
+		}
+		// insert se at head
+		else {
+			se->next		= cfs_rq->head;
+			cfs_rq->head->prev	= se;
+
+			// lastly reset the head
+			cfs_rq->head		= se;
+		}
+	} else {
+		// if empty rq
+		cfs_rq->head = se;
+		cfs_rq->tail = se;
+	}
+}
+
+static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *_se)
+{
+	struct cacule_node *se = &(_se->cacule_node);
+
+	// if only one se in rq
+	if (cfs_rq->head == cfs_rq->tail) {
+		cfs_rq->head = NULL;
+		cfs_rq->tail = NULL;
+
+	} else if (se == cfs_rq->head) {
+		// if it is the head
+		cfs_rq->head		= cfs_rq->head->next;
+		cfs_rq->head->prev	= NULL;
+	} else if (se == cfs_rq->tail) {
+		// if it is the tail
+		cfs_rq->tail		= cfs_rq->tail->prev;
+		cfs_rq->tail->next	= NULL;
+	} else {
+		// if in the middle
+		struct cacule_node *prev = se->prev;
+		struct cacule_node *next = se->next;
+
+		prev->next = next;
+
+		if (next)
+			next->prev = prev;
+	}
+}
+
+struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
+{
+	return se_of(cfs_rq->head);
+}
+#else
 /*
  * Enqueue an entity into the rb-tree:
  */
@@ -618,16 +809,24 @@ static struct sched_entity *__pick_next_entity(struct sched_entity *se)
 
 	return __node_2_se(next);
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 #ifdef CONFIG_SCHED_DEBUG
 struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
+#ifdef CONFIG_CACULE_SCHED
+	if (!cfs_rq->tail)
+		return NULL;
+
+	return se_of(cfs_rq->tail);
+#else
 	struct rb_node *last = rb_last(&cfs_rq->tasks_timeline.rb_root);
 
 	if (!last)
 		return NULL;
 
 	return __node_2_se(last);
+#endif /* CONFIG_CACULE_SCHED */
 }
 
 /**************************************************************
@@ -717,6 +916,7 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	return slice;
 }
 
+#if !defined(CONFIG_CACULE_SCHED)
 /*
  * We calculate the vruntime slice of a to-be-inserted task.
  *
@@ -726,6 +926,7 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	return calc_delta_fair(sched_slice(cfs_rq, se), se);
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 #include "pelt.h"
 #ifdef CONFIG_SMP
@@ -833,14 +1034,51 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq)
 }
 #endif /* CONFIG_SMP */
 
+#ifdef CONFIG_CACULE_SCHED
+static void normalize_lifetime(u64 now, struct sched_entity *se)
+{
+	struct cacule_node *cn = &se->cacule_node;
+	u64 max_life_ns, life_time;
+	s64 diff;
+
+	/*
+	 * left shift 20 bits is approximately = * 1000000
+	 * we don't need the precision of life time
+	 * Ex. for 30s, with left shift (20bits) == 31.457s
+	 */
+	max_life_ns	= ((u64) cacule_max_lifetime) << 20;
+	life_time	= now - cn->cacule_start_time;
+	diff		= life_time - max_life_ns;
+
+	if (diff > 0) {
+		// multiply life_time by 1024 for more precision
+		u64 old_hrrn_x	= (life_time << 7) / ((cn->vruntime >> 3) | 1);
+
+		// reset life to half max_life (i.e ~15s)
+		cn->cacule_start_time = now - (max_life_ns >> 1);
+
+		// avoid division by zero
+		if (old_hrrn_x == 0) old_hrrn_x = 1;
+
+		// reset vruntime based on old hrrn ratio
+		cn->vruntime = (max_life_ns << 9) / old_hrrn_x;
+	}
+}
+#endif /* CONFIG_CACULE_SCHED */
+
 /*
  * Update the current task's runtime statistics.
  */
 static void update_curr(struct cfs_rq *cfs_rq)
 {
 	struct sched_entity *curr = cfs_rq->curr;
+#ifdef CONFIG_CACULE_SCHED
+	u64 now = sched_clock();
+	u64 delta_exec, delta_fair;
+#else
 	u64 now = rq_clock_task(rq_of(cfs_rq));
 	u64 delta_exec;
+#endif
 
 	if (unlikely(!curr))
 		return;
@@ -857,8 +1095,15 @@ static void update_curr(struct cfs_rq *cfs_rq)
 	curr->sum_exec_runtime += delta_exec;
 	schedstat_add(cfs_rq->exec_clock, delta_exec);
 
+#ifdef CONFIG_CACULE_SCHED
+	delta_fair = calc_delta_fair(delta_exec, curr);
+	curr->vruntime += delta_fair;
+	curr->cacule_node.vruntime += delta_fair;
+	normalize_lifetime(now, curr);
+#else
 	curr->vruntime += calc_delta_fair(delta_exec, curr);
 	update_min_vruntime(cfs_rq);
+#endif
 
 	if (entity_is_task(curr)) {
 		struct task_struct *curtask = task_of(curr);
@@ -1026,7 +1271,6 @@ update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 static inline void
 update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
-
 	if (!schedstat_enabled())
 		return;
 
@@ -1058,7 +1302,11 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	/*
 	 * We are starting a new run period:
 	 */
+#ifdef CONFIG_CACULE_SCHED
+	se->exec_start = sched_clock();
+#else
 	se->exec_start = rq_clock_task(rq_of(cfs_rq));
+#endif
 }
 
 /**************************************************
@@ -4121,7 +4369,7 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {}
 
 static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-#ifdef CONFIG_SCHED_DEBUG
+#if defined(CONFIG_SCHED_DEBUG) && !defined(CONFIG_CACULE_SCHED)
 	s64 d = se->vruntime - cfs_rq->min_vruntime;
 
 	if (d < 0)
@@ -4132,6 +4380,7 @@ static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
 #endif
 }
 
+#if !defined(CONFIG_CACULE_SCHED)
 static void
 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 {
@@ -4163,6 +4412,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 	/* ensure we never gain time by being placed backwards. */
 	se->vruntime = max_vruntime(se->vruntime, vruntime);
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
 
@@ -4221,18 +4471,23 @@ static inline bool cfs_bandwidth_used(void);
 static void
 enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
+#if !defined(CONFIG_CACULE_SCHED)
 	bool renorm = !(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATED);
+#endif
 	bool curr = cfs_rq->curr == se;
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * If we're the current task, we must renormalise before calling
 	 * update_curr().
 	 */
 	if (renorm && curr)
 		se->vruntime += cfs_rq->min_vruntime;
+#endif
 
 	update_curr(cfs_rq);
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * Otherwise, renormalise after, such that we're placed at the current
 	 * moment in time, instead of some random moment in the past. Being
@@ -4241,6 +4496,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	 */
 	if (renorm && !curr)
 		se->vruntime += cfs_rq->min_vruntime;
+#endif
 
 	/*
 	 * When enqueuing a sched_entity, we must:
@@ -4255,8 +4511,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	update_cfs_group(se);
 	account_entity_enqueue(cfs_rq, se);
 
+#if !defined(CONFIG_CACULE_SCHED)
 	if (flags & ENQUEUE_WAKEUP)
 		place_entity(cfs_rq, se, 0);
+#endif
 
 	check_schedstat_required();
 	update_stats_enqueue(cfs_rq, se, flags);
@@ -4277,6 +4535,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 		check_enqueue_throttle(cfs_rq);
 }
 
+#if !defined(CONFIG_CACULE_SCHED)
 static void __clear_buddies_last(struct sched_entity *se)
 {
 	for_each_sched_entity(se) {
@@ -4321,6 +4580,7 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	if (cfs_rq->skip == se)
 		__clear_buddies_skip(se);
 }
+#endif /* !CONFIG_CACULE_SCHED */
 
 static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
 
@@ -4345,13 +4605,16 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 
 	update_stats_dequeue(cfs_rq, se, flags);
 
+#if !defined(CONFIG_CACULE_SCHED)
 	clear_buddies(cfs_rq, se);
+#endif
 
 	if (se != cfs_rq->curr)
 		__dequeue_entity(cfs_rq, se);
 	se->on_rq = 0;
 	account_entity_dequeue(cfs_rq, se);
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * Normalize after update_curr(); which will also have moved
 	 * min_vruntime if @se is the one holding it back. But before doing
@@ -4360,12 +4623,14 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	 */
 	if (!(flags & DEQUEUE_SLEEP))
 		se->vruntime -= cfs_rq->min_vruntime;
+#endif
 
 	/* return excess runtime on last dequeue */
 	return_cfs_rq_runtime(cfs_rq);
 
 	update_cfs_group(se);
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * Now advance min_vruntime if @se was the entity holding it back,
 	 * except when: DEQUEUE_SAVE && !DEQUEUE_MOVE, in this case we'll be
@@ -4374,8 +4639,21 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	 */
 	if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) != DEQUEUE_SAVE)
 		update_min_vruntime(cfs_rq);
+#endif
 }
 
+#ifdef CONFIG_CACULE_SCHED
+/*
+ * Preempt the current task with a newly woken task if needed:
+ */
+static void
+check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
+{
+	// does head have higher IS than curr
+	if (entity_before(sched_clock(), &curr->cacule_node, cfs_rq->head) == 1)
+		resched_curr(rq_of(cfs_rq));
+}
+#else
 /*
  * Preempt the current task with a newly woken task if needed:
  */
@@ -4415,6 +4693,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 	if (delta > ideal_runtime)
 		resched_curr(rq_of(cfs_rq));
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 static void
 set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -4449,6 +4728,21 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	se->prev_sum_exec_runtime = se->sum_exec_runtime;
 }
 
+#ifdef CONFIG_CACULE_SCHED
+static struct sched_entity *
+pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr)
+{
+	struct cacule_node *se = cfs_rq->head;
+
+	if (unlikely(!se))
+		se = &curr->cacule_node;
+	else if (unlikely(curr
+			&& entity_before(sched_clock(), se, &curr->cacule_node) == 1))
+		se = &curr->cacule_node;
+
+	return se_of(se);
+}
+#else
 static int
 wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
 
@@ -4509,6 +4803,7 @@ pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 
 	return se;
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
 
@@ -5611,7 +5906,9 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 	hrtick_update(rq);
 }
 
+#if !defined(CONFIG_CACULE_SCHED)
 static void set_next_buddy(struct sched_entity *se);
+#endif
 
 /*
  * The dequeue_task method is called before nr_running is
@@ -5643,12 +5940,14 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 		if (cfs_rq->load.weight) {
 			/* Avoid re-evaluating load for this entity: */
 			se = parent_entity(se);
+#if !defined(CONFIG_CACULE_SCHED)
 			/*
 			 * Bias pick_next to pick a task from this cfs_rq, as
 			 * p is sleeping when it is within its sched_slice.
 			 */
 			if (task_sleep && se && !throttled_hierarchy(cfs_rq))
 				set_next_buddy(se);
+#endif
 			break;
 		}
 		flags |= DEQUEUE_SLEEP;
@@ -5764,6 +6063,7 @@ static unsigned long capacity_of(int cpu)
 	return cpu_rq(cpu)->cpu_capacity;
 }
 
+#if !defined(CONFIG_CACULE_SCHED)
 static void record_wakee(struct task_struct *p)
 {
 	/*
@@ -5810,6 +6110,7 @@ static int wake_wide(struct task_struct *p)
 		return 0;
 	return 1;
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 /*
  * The purpose of wake_affine() is to quickly determine on which CPU we can run
@@ -6512,6 +6813,7 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
 	return min_t(unsigned long, util, capacity_orig_of(cpu));
 }
 
+#if !defined(CONFIG_CACULE_SCHED)
 /*
  * Predicts what cpu_util(@cpu) would return if @p was migrated (and enqueued)
  * to @dst_cpu.
@@ -6761,6 +7063,57 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu)
 
 	return -1;
 }
+#endif /* CONFIG_CACULE_SCHED */
+
+#ifdef CONFIG_CACULE_SCHED
+static int
+find_least_IS_cpu(struct task_struct *p)
+{
+	struct cfs_rq *cfs_rq;
+	unsigned int max_IS = 0;
+	unsigned int IS, IS_c, IS_h;
+	struct sched_entity *curr_se;
+	struct cacule_node *cn, *head;
+	int cpu_i;
+	int new_cpu = -1;
+
+	for_each_online_cpu(cpu_i) {
+		if (!cpumask_test_cpu(cpu_i, p->cpus_ptr))
+			continue;
+
+		cn = NULL;
+		cfs_rq = &cpu_rq(cpu_i)->cfs;
+
+		curr_se = cfs_rq->curr;
+		head = cfs_rq->head;
+
+		if (!curr_se && head)
+			cn = head;
+		else if (curr_se && !head)
+			cn = &curr_se->cacule_node;
+		else if (curr_se && head) {
+			IS_c = calc_interactivity(sched_clock(), &curr_se->cacule_node);
+			IS_h = calc_interactivity(sched_clock(), head);
+
+			IS = IS_c > IS_h? IS_c : IS_h;
+			goto compare;
+		}
+
+		if (!cn)
+			return cpu_i;
+
+		IS = calc_interactivity(sched_clock(), cn);
+
+compare:
+		if (IS > max_IS) {
+			max_IS = IS;
+			new_cpu = cpu_i;
+		}
+	}
+
+	return new_cpu;
+}
+#endif
 
 /*
  * select_task_rq_fair: Select target runqueue for the waking task in domains
@@ -6785,6 +7138,26 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags)
 	/* SD_flags and WF_flags share the first nibble */
 	int sd_flag = wake_flags & 0xF;
 
+#ifdef CONFIG_CACULE_SCHED
+	struct sched_entity *se = &p->se;
+
+	if (!is_interactive(&se->cacule_node))
+		goto cfs_way;
+
+	// check first if the prev cpu
+	// has 0 tasks
+	if (cpumask_test_cpu(prev_cpu, p->cpus_ptr) &&
+	    cpu_rq(prev_cpu)->cfs.nr_running == 0)
+		return prev_cpu;
+
+	new_cpu = find_least_IS_cpu(p);
+
+	if (new_cpu != -1)
+		return new_cpu;
+
+	new_cpu = prev_cpu;
+cfs_way:
+#else
 	if (wake_flags & WF_TTWU) {
 		record_wakee(p);
 
@@ -6797,6 +7170,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags)
 
 		want_affine = !wake_wide(p) && cpumask_test_cpu(cpu, p->cpus_ptr);
 	}
+#endif /* CONFIG_CACULE_SCHED */
 
 	rcu_read_lock();
 	for_each_domain(cpu, tmp) {
@@ -6843,6 +7217,7 @@ static void detach_entity_cfs_rq(struct sched_entity *se);
  */
 static void migrate_task_rq_fair(struct task_struct *p, int new_cpu)
 {
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * As blocked tasks retain absolute vruntime the migration needs to
 	 * deal with this by subtracting the old and adding the new
@@ -6868,6 +7243,7 @@ static void migrate_task_rq_fair(struct task_struct *p, int new_cpu)
 
 		se->vruntime -= min_vruntime;
 	}
+#endif /* CONFIG_CACULE_SCHED */
 
 	if (p->on_rq == TASK_ON_RQ_MIGRATING) {
 		/*
@@ -6913,6 +7289,7 @@ balance_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 }
 #endif /* CONFIG_SMP */
 
+#if !defined(CONFIG_CACULE_SCHED)
 static unsigned long wakeup_gran(struct sched_entity *se)
 {
 	unsigned long gran = sysctl_sched_wakeup_granularity;
@@ -6991,6 +7368,7 @@ static void set_skip_buddy(struct sched_entity *se)
 	for_each_sched_entity(se)
 		cfs_rq_of(se)->skip = se;
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 /*
  * Preempt the current task with a newly woken task if needed:
@@ -6999,9 +7377,12 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 {
 	struct task_struct *curr = rq->curr;
 	struct sched_entity *se = &curr->se, *pse = &p->se;
+
+#if !defined(CONFIG_CACULE_SCHED)
 	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
 	int scale = cfs_rq->nr_running >= sched_nr_latency;
 	int next_buddy_marked = 0;
+#endif /* CONFIG_CACULE_SCHED */
 
 	if (unlikely(se == pse))
 		return;
@@ -7015,10 +7396,12 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 	if (unlikely(throttled_hierarchy(cfs_rq_of(pse))))
 		return;
 
+#if !defined(CONFIG_CACULE_SCHED)
 	if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) {
 		set_next_buddy(pse);
 		next_buddy_marked = 1;
 	}
+#endif /* CONFIG_CACULE_SCHED */
 
 	/*
 	 * We can come here with TIF_NEED_RESCHED already set from new task
@@ -7048,6 +7431,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 	find_matching_se(&se, &pse);
 	update_curr(cfs_rq_of(se));
 	BUG_ON(!pse);
+
+#ifdef CONFIG_CACULE_SCHED
+	if (entity_before(sched_clock(), &se->cacule_node, &pse->cacule_node) == 1)
+		goto preempt;
+#else
 	if (wakeup_preempt_entity(se, pse) == 1) {
 		/*
 		 * Bias pick_next to pick the sched entity that is
@@ -7057,11 +7445,14 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 			set_next_buddy(pse);
 		goto preempt;
 	}
+#endif /* CONFIG_CACULE_SCHED */
 
 	return;
 
 preempt:
 	resched_curr(rq);
+
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * Only set the backward buddy when the current task is still
 	 * on the rq. This can happen when a wakeup gets interleaved
@@ -7076,6 +7467,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 
 	if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
 		set_last_buddy(se);
+#endif /* CONFIG_CACULE_SCHED */
 }
 
 struct task_struct *
@@ -7250,7 +7642,10 @@ static void yield_task_fair(struct rq *rq)
 {
 	struct task_struct *curr = rq->curr;
 	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
+
+#if !defined(CONFIG_CACULE_SCHED)
 	struct sched_entity *se = &curr->se;
+#endif
 
 	/*
 	 * Are we the only task in the tree?
@@ -7258,7 +7653,9 @@ static void yield_task_fair(struct rq *rq)
 	if (unlikely(rq->nr_running == 1))
 		return;
 
+#if !defined(CONFIG_CACULE_SCHED)
 	clear_buddies(cfs_rq, se);
+#endif
 
 	if (curr->policy != SCHED_BATCH) {
 		update_rq_clock(rq);
@@ -7274,7 +7671,9 @@ static void yield_task_fair(struct rq *rq)
 		rq_clock_skip_update(rq);
 	}
 
+#if !defined(CONFIG_CACULE_SCHED)
 	set_skip_buddy(se);
+#endif
 }
 
 static bool yield_to_task_fair(struct rq *rq, struct task_struct *p)
@@ -7285,8 +7684,10 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p)
 	if (!se->on_rq || throttled_hierarchy(cfs_rq_of(se)))
 		return false;
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/* Tell the scheduler that we'd really like pse to run next. */
 	set_next_buddy(se);
+#endif
 
 	yield_task_fair(rq);
 
@@ -7513,6 +7914,7 @@ static int task_hot(struct task_struct *p, struct lb_env *env)
 	if (env->sd->flags & SD_SHARE_CPUCAPACITY)
 		return 0;
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/*
 	 * Buddy candidates are cache hot:
 	 */
@@ -7520,6 +7922,7 @@ static int task_hot(struct task_struct *p, struct lb_env *env)
 			(&p->se == cfs_rq_of(&p->se)->next ||
 			 &p->se == cfs_rq_of(&p->se)->last))
 		return 1;
+#endif
 
 	if (sysctl_sched_migration_cost == -1)
 		return 1;
@@ -10547,9 +10950,11 @@ static void nohz_newidle_balance(struct rq *this_rq)
 	if (!housekeeping_cpu(this_cpu, HK_FLAG_SCHED))
 		return;
 
+#if !defined(CONFIG_CACULE_SCHED)
 	/* Will wake up very soon. No time for doing anything else*/
 	if (this_rq->avg_idle < sysctl_sched_migration_cost)
 		return;
+#endif
 
 	/* Don't need to update blocked load of idle CPUs*/
 	if (!READ_ONCE(nohz.has_blocked) ||
@@ -10612,7 +11017,10 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 	 */
 	rq_unpin_lock(this_rq, rf);
 
-	if (this_rq->avg_idle < sysctl_sched_migration_cost ||
+	if (
+#if !defined(CONFIG_CACULE_SCHED)
+	    this_rq->avg_idle < sysctl_sched_migration_cost ||
+#endif
 	    !READ_ONCE(this_rq->rd->overload)) {
 
 		rcu_read_lock();
@@ -10780,11 +11188,28 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 	update_overutilized_status(task_rq(curr));
 }
 
+#ifdef CONFIG_CACULE_SCHED
 /*
  * called on fork with the child task as argument from the parent's context
  *  - child not yet on the tasklist
  *  - preemption disabled
  */
+ static void task_fork_fair(struct task_struct *p)
+{
+	struct cfs_rq *cfs_rq;
+	struct rq *rq = this_rq();
+	struct rq_flags rf;
+
+	rq_lock(rq, &rf);
+	update_rq_clock(rq);
+
+	cfs_rq = task_cfs_rq(current);
+	if (cfs_rq->curr)
+		update_curr(cfs_rq);
+
+	rq_unlock(rq, &rf);
+}
+#else
 static void task_fork_fair(struct task_struct *p)
 {
 	struct cfs_rq *cfs_rq;
@@ -10815,6 +11240,7 @@ static void task_fork_fair(struct task_struct *p)
 	se->vruntime -= cfs_rq->min_vruntime;
 	rq_unlock(rq, &rf);
 }
+#endif /* CONFIG_CACULE_SCHED */
 
 /*
  * Priority of the task has changed. Check to see if we preempt
@@ -10933,6 +11359,8 @@ static void attach_entity_cfs_rq(struct sched_entity *se)
 static void detach_task_cfs_rq(struct task_struct *p)
 {
 	struct sched_entity *se = &p->se;
+
+#if !defined(CONFIG_CACULE_SCHED)
 	struct cfs_rq *cfs_rq = cfs_rq_of(se);
 
 	if (!vruntime_normalized(p)) {
@@ -10943,6 +11371,7 @@ static void detach_task_cfs_rq(struct task_struct *p)
 		place_entity(cfs_rq, se, 0);
 		se->vruntime -= cfs_rq->min_vruntime;
 	}
+#endif
 
 	detach_entity_cfs_rq(se);
 }
@@ -10950,12 +11379,17 @@ static void detach_task_cfs_rq(struct task_struct *p)
 static void attach_task_cfs_rq(struct task_struct *p)
 {
 	struct sched_entity *se = &p->se;
+
+#if !defined(CONFIG_CACULE_SCHED)
 	struct cfs_rq *cfs_rq = cfs_rq_of(se);
+#endif
 
 	attach_entity_cfs_rq(se);
 
+#if !defined(CONFIG_CACULE_SCHED)
 	if (!vruntime_normalized(p))
 		se->vruntime += cfs_rq->min_vruntime;
+#endif
 }
 
 static void switched_from_fair(struct rq *rq, struct task_struct *p)
@@ -11011,13 +11445,22 @@ static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
 void init_cfs_rq(struct cfs_rq *cfs_rq)
 {
 	cfs_rq->tasks_timeline = RB_ROOT_CACHED;
+
+#if !defined(CONFIG_CACULE_SCHED)
 	cfs_rq->min_vruntime = (u64)(-(1LL << 20));
 #ifndef CONFIG_64BIT
 	cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
 #endif
+#endif /* CONFIG_CACULE_SCHED */
+
 #ifdef CONFIG_SMP
 	raw_spin_lock_init(&cfs_rq->removed.lock);
 #endif
+
+#ifdef CONFIG_CACULE_SCHED
+	cfs_rq->head = NULL;
+	cfs_rq->tail = NULL;
+#endif
 }
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index a189bec13729..0affe3be7c21 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -525,10 +525,13 @@ struct cfs_rq {
 	unsigned int		idle_h_nr_running; /* SCHED_IDLE */
 
 	u64			exec_clock;
+
+#if !defined(CONFIG_CACULE_SCHED)
 	u64			min_vruntime;
 #ifndef CONFIG_64BIT
 	u64			min_vruntime_copy;
 #endif
+#endif /* CONFIG_CACULE_SCHED */
 
 	struct rb_root_cached	tasks_timeline;
 
@@ -537,9 +540,15 @@ struct cfs_rq {
 	 * It is set to NULL otherwise (i.e when none are currently running).
 	 */
 	struct sched_entity	*curr;
+#ifdef CONFIG_CACULE_SCHED
+	struct cacule_node	*head;
+	struct cacule_node	*tail;
+
+#else
 	struct sched_entity	*next;
 	struct sched_entity	*last;
 	struct sched_entity	*skip;
+#endif // CONFIG_CACULE_SCHED
 
 #ifdef	CONFIG_SCHED_DEBUG
 	unsigned int		nr_spread_over;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d4a78e08f6d8..e8cdedf74fed 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1736,6 +1736,29 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#ifdef CONFIG_CACULE_SCHED
+	{
+		.procname	= "sched_interactivity_factor",
+		.data		= &interactivity_factor,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "sched_interactivity_threshold",
+		.data		= &interactivity_threshold,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "sched_max_lifetime_ms",
+		.data		= &cacule_max_lifetime,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#endif
 #ifdef CONFIG_SCHEDSTATS
 	{
 		.procname	= "sched_schedstats",