0001-linux5.10.y-bore5.1.0.patch

From 60a78397ed1cce95e3d1b22b0ea4adf9f2141de7 Mon Sep 17 00:00:00 2001
From: Masahito S <firelzrd@gmail.com>
Date: Thu, 28 Mar 2024 00:47:09 +0900
Subject: [PATCH] linux5.15.y-bore5.1.0

---
 include/linux/sched.h |  10 +++
 init/Kconfig          |  17 +++++
 kernel/sched/core.c   | 143 ++++++++++++++++++++++++++++++++++++++++++
 kernel/sched/debug.c  |   3 +
 kernel/sched/fair.c   | 122 ++++++++++++++++++++++++++++++-----
 kernel/sysctl.c       |  76 ++++++++++++++++++++++
 6 files changed, 357 insertions(+), 14 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 7bfc2b45cd..7058ceab13 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -535,6 +535,16 @@ struct sched_entity {
 	u64				sum_exec_runtime;
 	u64				vruntime;
 	u64				prev_sum_exec_runtime;
+#ifdef CONFIG_SCHED_BORE
+	u64				burst_time;
+	u8				prev_burst_penalty;
+	u8				curr_burst_penalty;
+	u8				burst_penalty;
+	u8				burst_score;
+	u8				child_burst;
+	u32				child_burst_cnt;
+	u64				child_burst_last_cached;
+#endif // CONFIG_SCHED_BORE
 
 	u64				nr_migrations;
 
diff --git a/init/Kconfig b/init/Kconfig
index dafc3ba6fa..64bcc7e6e5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1266,6 +1266,23 @@ config CHECKPOINT_RESTORE
 
 	  If unsure, say N here.
 
+config SCHED_BORE
+	bool "Burst-Oriented Response Enhancer"
+	default y
+	help
+	  In Desktop and Mobile computing, one might prefer interactive
+	  tasks to keep responsive no matter what they run in the background.
+
+	  Enabling this kernel feature modifies the scheduler to discriminate
+	  tasks by their burst time (runtime since it last went sleeping or
+	  yielding state) and prioritize those that run less bursty.
+	  Such tasks usually include window compositor, widgets backend,
+	  terminal emulator, video playback, games and so on.
+	  With a little impact to scheduling fairness, it may improve
+	  responsiveness especially under heavy background workload.
+
+	  If unsure, say Y here.
+
 config SCHED_AUTOGROUP
 	bool "Automatic process group scheduling"
 	select CGROUPS
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 25b8ea9116..937c0abb86 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4221,6 +4221,138 @@ int wake_up_state(struct task_struct *p, unsigned int state)
 	return try_to_wake_up(p, state, 0);
 }
 
+#ifdef CONFIG_SCHED_BORE
+extern u8   sched_burst_fork_atavistic;
+extern uint sched_burst_cache_lifetime;
+
+static void __init sched_init_bore(void) {
+	init_task.se.burst_time = 0;
+	init_task.se.prev_burst_penalty = 0;
+	init_task.se.curr_burst_penalty = 0;
+	init_task.se.burst_penalty = 0;
+	init_task.se.burst_score = 0;
+	init_task.se.child_burst_last_cached = 0;
+}
+
+void inline sched_fork_bore(struct task_struct *p) {
+	p->se.burst_time = 0;
+	p->se.curr_burst_penalty = 0;
+	p->se.burst_score = 0;
+	p->se.child_burst_last_cached = 0;
+}
+
+static u32 count_child_tasks(struct task_struct *p) {
+	struct task_struct *child;
+	u32 cnt = 0;
+	list_for_each_entry(child, &p->children, sibling) {cnt++;}
+	return cnt;
+}
+
+static inline bool task_is_inheritable(struct task_struct *p) {
+	return (p->sched_class == &fair_sched_class);
+}
+
+static inline bool child_burst_cache_expired(struct task_struct *p, u64 now) {
+	u64 expiration_time =
+		p->se.child_burst_last_cached + sched_burst_cache_lifetime;
+	return ((s64)(expiration_time - now) < 0);
+}
+
+static void __update_child_burst_cache(
+	struct task_struct *p, u32 cnt, u32 sum, u64 now) {
+	u8 avg = 0;
+	if (cnt) avg = sum / cnt;
+	p->se.child_burst = max(avg, p->se.burst_penalty);
+	p->se.child_burst_cnt = cnt;
+	p->se.child_burst_last_cached = now;
+}
+
+static inline void update_child_burst_direct(struct task_struct *p, u64 now) {
+	struct task_struct *child;
+	u32 cnt = 0;
+	u32 sum = 0;
+
+	list_for_each_entry(child, &p->children, sibling) {
+		if (!task_is_inheritable(child)) continue;
+		cnt++;
+		sum += child->se.burst_penalty;
+	}
+
+	__update_child_burst_cache(p, cnt, sum, now);
+}
+
+static inline u8 __inherit_burst_direct(struct task_struct *p, u64 now) {
+	struct task_struct *parent = p->real_parent;
+	if (child_burst_cache_expired(parent, now))
+		update_child_burst_direct(parent, now);
+
+	return parent->se.child_burst;
+}
+
+static void update_child_burst_topological(
+	struct task_struct *p, u64 now, u32 depth, u32 *acnt, u32 *asum) {
+	struct task_struct *child, *dec;
+	u32 cnt = 0, dcnt = 0;
+	u32 sum = 0;
+
+	list_for_each_entry(child, &p->children, sibling) {
+		dec = child;
+		while ((dcnt = count_child_tasks(dec)) == 1)
+			dec = list_first_entry(&dec->children, struct task_struct, sibling);
+		
+		if (!dcnt || !depth) {
+			if (!task_is_inheritable(dec)) continue;
+			cnt++;
+			sum += dec->se.burst_penalty;
+			continue;
+		}
+		if (!child_burst_cache_expired(dec, now)) {
+			cnt += dec->se.child_burst_cnt;
+			sum += (u32)dec->se.child_burst * dec->se.child_burst_cnt;
+			continue;
+		}
+		update_child_burst_topological(dec, now, depth - 1, &cnt, &sum);
+	}
+
+	__update_child_burst_cache(p, cnt, sum, now);
+	*acnt += cnt;
+	*asum += sum;
+}
+
+static inline u8 __inherit_burst_topological(struct task_struct *p, u64 now) {
+	struct task_struct *anc = p->real_parent;
+	u32 cnt = 0, sum = 0;
+
+	while (anc->real_parent != anc && count_child_tasks(anc) == 1)
+		anc = anc->real_parent;
+
+	if (child_burst_cache_expired(anc, now))
+		update_child_burst_topological(
+			anc, now, sched_burst_fork_atavistic - 1, &cnt, &sum);
+
+	return anc->se.child_burst;
+}
+
+static inline void inherit_burst(struct task_struct *p) {
+	u8 burst_cache;
+	u64 now = ktime_get_ns();
+
+	read_lock(&tasklist_lock);
+	burst_cache = likely(sched_burst_fork_atavistic)?
+		__inherit_burst_topological(p, now):
+		__inherit_burst_direct(p, now);
+	read_unlock(&tasklist_lock);
+
+	p->se.prev_burst_penalty = max(p->se.prev_burst_penalty, burst_cache);
+}
+
+static void sched_post_fork_bore(struct task_struct *p) {
+	if (p->sched_class == &fair_sched_class)
+		inherit_burst(p);
+	p->se.burst_penalty = p->se.prev_burst_penalty;
+}
+#endif // CONFIG_SCHED_BORE
+
 /*
  * Perform scheduler related setup for a newly forked process p.
  * p is forked by current.
@@ -4237,6 +4369,9 @@ 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_SCHED_BORE
+	sched_fork_bore(p);
+#endif // CONFIG_SCHED_BORE
 	INIT_LIST_HEAD(&p->se.group_node);
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -4469,6 +4604,9 @@ void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs)
 
 void sched_post_fork(struct task_struct *p)
 {
+#ifdef CONFIG_SCHED_BORE
+	sched_post_fork_bore(p);
+#endif // CONFIG_SCHED_BORE
 	uclamp_post_fork(p);
 }
 
@@ -9381,6 +9519,11 @@ void __init sched_init(void)
 	BUG_ON(&dl_sched_class + 1 != &stop_sched_class);
 #endif
 
+#ifdef CONFIG_SCHED_BORE
+	sched_init_bore();
+	printk(KERN_INFO "BORE (Burst-Oriented Response Enhancer) CPU Scheduler modification 5.1.0 by Masahito Suzuki");
+#endif // CONFIG_SCHED_BORE
+
 	wait_bit_init();
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 5ffe16ff03..de5345d03b 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -545,6 +545,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 		SPLIT_NS(p->se.sum_exec_runtime),
 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)));
 
+#ifdef CONFIG_SCHED_BORE
+	SEQ_printf(m, " %2d", p->se.burst_score);
+#endif // CONFIG_SCHED_BORE
 #ifdef CONFIG_NUMA_BALANCING
 	SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
 #endif
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index fd8b565664..8c4c060510 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -19,6 +19,9 @@
  *
  *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
+ *
+ *  Burst-Oriented Response Enhancer (BORE) CPU Scheduler
+ *  Copyright (C) 2021-2024 Masahito Suzuki <firelzrd@gmail.com>
  */
 #include "sched.h"
 
@@ -84,6 +87,74 @@ static unsigned int normalized_sysctl_sched_wakeup_granularity	= 1000000UL;
 
 const_debug unsigned int sysctl_sched_migration_cost	= 500000UL;
 
+#ifdef CONFIG_SCHED_BORE
+bool __read_mostly sched_bore                   = 1;
+bool __read_mostly sched_burst_smoothness_long  = 1;
+bool __read_mostly sched_burst_smoothness_short = 0;
+u8   __read_mostly sched_burst_fork_atavistic   = 2;
+u8   __read_mostly sched_burst_penalty_offset   = 22;
+uint __read_mostly sched_burst_penalty_scale    = 1280;
+uint __read_mostly sched_burst_cache_lifetime   = 60000000;
+
+#define MAX_BURST_PENALTY (39U <<2)
+
+static inline u32 log2plus1_u64_u32f8(u64 v) {
+	u32 msb = fls64(v);
+	s32 excess_bits = msb - 9;
+    u8 fractional = (0 <= excess_bits)? v >> excess_bits: v << -excess_bits;
+	return msb << 8 | fractional;
+}
+
+static inline u32 calc_burst_penalty(u64 burst_time) {
+	u32 greed, tolerance, penalty, scaled_penalty;
+	
+	greed = log2plus1_u64_u32f8(burst_time);
+	tolerance = sched_burst_penalty_offset << 8;
+	penalty = max(0, (s32)greed - (s32)tolerance);
+	scaled_penalty = penalty * sched_burst_penalty_scale >> 16;
+
+	return min(MAX_BURST_PENALTY, scaled_penalty);
+}
+
+static inline u64 scale_slice(u64 delta, struct sched_entity *se) {
+	return mul_u64_u32_shr(delta, sched_prio_to_wmult[se->burst_score], 22);
+}
+
+static void update_burst_score(struct sched_entity *se) {
+	if (!entity_is_task(se)) return;
+	struct task_struct *p = task_of(se);
+	u8 prio = p->static_prio - MAX_RT_PRIO;
+	u8 prev_prio = min(39, prio + se->burst_score);
+
+	se->burst_score = se->burst_penalty >> 2;
+
+	u8 new_prio = min(39, prio + se->burst_score);
+	if (new_prio != prev_prio)
+		reweight_task(p, new_prio);
+}
+
+static void update_burst_penalty(struct sched_entity *se) {
+	se->curr_burst_penalty = calc_burst_penalty(se->burst_time);
+	se->burst_penalty = max(se->prev_burst_penalty, se->curr_burst_penalty);
+	update_burst_score(se);
+}
+
+static inline u32 binary_smooth(u32 new, u32 old) {
+  int increment = new - old;
+  return (0 <= increment)?
+    old + ( increment >> (int)sched_burst_smoothness_long):
+    old - (-increment >> (int)sched_burst_smoothness_short);
+}
+
+static void restart_burst(struct sched_entity *se) {
+	se->burst_penalty = se->prev_burst_penalty =
+		binary_smooth(se->curr_burst_penalty, se->prev_burst_penalty);
+	se->curr_burst_penalty = 0;
+	se->burst_time = 0;
+	update_burst_score(se);
+}
+#endif // CONFIG_SCHED_BORE
+
 int sched_thermal_decay_shift;
 static int __init setup_sched_thermal_decay_shift(char *str)
 {
@@ -645,7 +716,6 @@ static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
 {
 	if (unlikely(se->load.weight != NICE_0_LOAD))
 		delta = __calc_delta(delta, NICE_0_LOAD, &se->load);
-
 	return delta;
 }
 
@@ -848,7 +918,13 @@ 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_SCHED_BORE
+	curr->burst_time += delta_exec;
+	update_burst_penalty(curr);
+	curr->vruntime += max(1ULL, calc_delta_fair(delta_exec, curr));
+#else // !CONFIG_SCHED_BORE
 	curr->vruntime += calc_delta_fair(delta_exec, curr);
+#endif // CONFIG_SCHED_BORE
 	update_min_vruntime(cfs_rq);
 
 	if (entity_is_task(curr)) {
@@ -5907,6 +5983,14 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 	bool was_sched_idle = sched_idle_rq(rq);
 
 	util_est_dequeue(&rq->cfs, p);
+#ifdef CONFIG_SCHED_BORE
+	if (task_sleep) {
+		cfs_rq = cfs_rq_of(se);
+		if (cfs_rq->curr == se)
+			update_curr(cfs_rq);
+		restart_burst(se);
+	}
+#endif // CONFIG_SCHED_BORE
 
 	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);
@@ -7660,24 +7744,31 @@ static void yield_task_fair(struct rq *rq)
 	/*
 	 * Are we the only task in the tree?
 	 */
+#if !defined(CONFIG_SCHED_BORE)
 	if (unlikely(rq->nr_running == 1))
 		return;
 
 	clear_buddies(cfs_rq, se);
+#endif // CONFIG_SCHED_BORE
 
-	if (curr->policy != SCHED_BATCH) {
-		update_rq_clock(rq);
-		/*
-		 * Update run-time statistics of the 'current'.
-		 */
-		update_curr(cfs_rq);
-		/*
-		 * Tell update_rq_clock() that we've just updated,
-		 * so we don't do microscopic update in schedule()
-		 * and double the fastpath cost.
-		 */
-		rq_clock_skip_update(rq);
-	}
+	update_rq_clock(rq);
+	/*
+	 * Update run-time statistics of the 'current'.
+	 */
+	update_curr(cfs_rq);
+#ifdef CONFIG_SCHED_BORE
+	restart_burst(se);
+	if (unlikely(rq->nr_running == 1))
+		return;
+
+	clear_buddies(cfs_rq, se);
+#endif // CONFIG_SCHED_BORE
+	/*
+	 * Tell update_rq_clock() that we've just updated,
+	 * so we don't do microscopic update in schedule()
+	 * and double the fastpath cost.
+	 */
+	rq_clock_skip_update(rq);
 
 	set_skip_buddy(se);
 }
@@ -11486,6 +11577,9 @@ static void task_fork_fair(struct task_struct *p)
 		update_curr(cfs_rq);
 		se->vruntime = curr->vruntime;
 	}
+#ifdef CONFIG_SCHED_BORE
+	update_burst_score(se);
+#endif // CONFIG_SCHED_BORE
 	place_entity(cfs_rq, se, 1);
 
 	if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) {
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 928798f89c..27d197c737 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -133,6 +133,19 @@ static int minolduid;
 static int ngroups_max = NGROUPS_MAX;
 static const int cap_last_cap = CAP_LAST_CAP;
 
+#ifdef CONFIG_SCHED_BORE
+extern u8   sched_bore;
+extern u8   sched_burst_smoothness_long;
+extern u8   sched_burst_smoothness_short;
+extern u8   sched_burst_fork_atavistic;
+extern u8   sched_burst_penalty_offset;
+extern uint sched_burst_penalty_scale;
+extern uint sched_burst_cache_lifetime;
+static int __maybe_unused three          = 3;
+static int __maybe_unused sixty_four     = 64;
+static int __maybe_unused maxval_12_bits = 4095;
+#endif // CONFIG_SCHED_BORE
+
 /*
  * This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs
  * and hung_task_check_interval_secs
@@ -1775,6 +1788,69 @@ int proc_do_static_key(struct ctl_table *table, int write,
 }
 
 static struct ctl_table kern_table[] = {
+#ifdef CONFIG_SCHED_BORE
+	{
+		.procname	= "sched_bore",
+		.data		= &sched_bore,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ONE,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "sched_burst_smoothness_long",
+		.data		= &sched_burst_smoothness_long,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "sched_burst_smoothness_short",
+		.data		= &sched_burst_smoothness_short,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "sched_burst_fork_atavistic",
+		.data		= &sched_burst_fork_atavistic,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &three,
+	},
+	{
+		.procname	= "sched_burst_penalty_offset",
+		.data		= &sched_burst_penalty_offset,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &sixty_four,
+	},
+	{
+		.procname	= "sched_burst_penalty_scale",
+		.data		= &sched_burst_penalty_scale,
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler = proc_douintvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &maxval_12_bits,
+	},
+	{
+		.procname	= "sched_burst_cache_lifetime",
+		.data		= &sched_burst_cache_lifetime,
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler = proc_douintvec,
+	},
+#endif // CONFIG_SCHED_BORE
 	{
 		.procname	= "sched_child_runs_first",
 		.data		= &sysctl_sched_child_runs_first,
-- 
2.34.1