path: root/0001-linux6.0.y-bore1.7.5.patch

From 33d4c5a2808aeb991653f9c4cecd7320434f1ea1 Mon Sep 17 00:00:00 2001
From: Masahito S <firelzrd@gmail.com>
Date: Sun, 18 Dec 2022 15:26:15 +0900
Subject: [PATCH] linux6.0.y-bore1.7.5

---
 include/linux/sched.h   |   5 ++
 init/Kconfig            |  20 +++++
 kernel/sched/core.c     |  29 +++++++
 kernel/sched/debug.c    |   3 +
 kernel/sched/fair.c     | 166 ++++++++++++++++++++++++++++++++++++++--
 kernel/sched/features.h |   4 +
 6 files changed, 220 insertions(+), 7 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8d82d6d32..a53340011 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -545,6 +545,11 @@ struct sched_entity {
 	u64				sum_exec_runtime;
 	u64				vruntime;
 	u64				prev_sum_exec_runtime;
+#ifdef CONFIG_SCHED_BORE
+	u64				prev_burst_time;
+	u64				burst_time;
+	u8				burst_score;
+#endif // CONFIG_SCHED_BORE
 
 	u64				nr_migrations;
 
diff --git a/init/Kconfig b/init/Kconfig
index d1d779d6b..04a0b6b20 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1272,6 +1272,26 @@ 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.
+
+	  You can turn it off by setting the sysctl kernel.sched_bore = 0.
+	  Enabling this feature implies NO_GENTLE_FAIR_SLEEPERS by default.
+
+	  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 ee28253c9..0a9d220fc 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4320,6 +4320,22 @@ int wake_up_state(struct task_struct *p, unsigned int state)
 	return try_to_wake_up(p, state, 0);
 }
 
+#ifdef CONFIG_SCHED_BORE
+static inline void sched_on_fork_calc_prev_burst_from_siblings(struct task_struct *p)
+{
+	struct task_struct *sib;
+	u64 sum = 0, avg = 0;
+	u32 cnt = 0;
+	list_for_each_entry(sib, &p->sibling, sibling) {
+		cnt++;
+		sum += sib->se.prev_burst_time;
+	}
+	if (cnt) avg = sum / cnt;
+	p->se.prev_burst_time = max(p->se.prev_burst_time, avg);
+	p->se.burst_time = 0;
+}
+#endif // CONFIG_SCHED_BORE
+
 /*
  * Perform scheduler related setup for a newly forked process p.
  * p is forked by current.
@@ -4336,6 +4352,9 @@ 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
+	p->se.burst_time      = 0;
+#endif // CONFIG_SCHED_BORE
 	INIT_LIST_HEAD(&p->se.group_node);
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -4536,6 +4555,9 @@ late_initcall(sched_core_sysctl_init);
 int sched_fork(unsigned long clone_flags, struct task_struct *p)
 {
 	__sched_fork(clone_flags, p);
+#ifdef CONFIG_SCHED_BORE
+	sched_on_fork_calc_prev_burst_from_siblings(p);
+#endif // CONFIG_SCHED_BORE
 	/*
 	 * We mark the process as NEW here. This guarantees that
 	 * nobody will actually run it, and a signal or other external
@@ -8947,6 +8969,9 @@ void __init init_idle(struct task_struct *idle, int cpu)
 
 	idle->__state = TASK_RUNNING;
 	idle->se.exec_start = sched_clock();
+#ifdef CONFIG_SCHED_BORE
+	idle->se.prev_burst_time = 0;
+#endif //CONFIG_SCHED_BORE
 	/*
 	 * PF_KTHREAD should already be set at this point; regardless, make it
 	 * look like a proper per-CPU kthread.
@@ -9617,6 +9642,10 @@ void __init sched_init(void)
 	BUG_ON(&dl_sched_class != &stop_sched_class + 1);
 #endif
 
+#ifdef CONFIG_SCHED_BORE
+	printk(KERN_INFO "BORE (Burst-Oriented Response Enhancer) CPU Scheduler modification 1.7.5 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 667876da8..e9f7a9cb0 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -546,6 +546,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)),
 		SPLIT_NS(schedstat_val_or_zero(p->stats.sum_block_runtime)));
 
+#ifdef CONFIG_SCHED_BORE
+	SEQ_printf(m, " %2d", p->se.burst_score);
+#endif
 #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 914096c5b..a37e26794 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 Masahito Suzuki <firelzrd@gmail.com>
  */
 #include <linux/energy_model.h>
 #include <linux/mmap_lock.h>
@@ -66,10 +69,16 @@
  * (to see the precise effective timeslice length of your workload,
  *  run vmstat and monitor the context-switches (cs) field)
  *
- * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
+ * (BORE default: 12.8ms constant, units: nanoseconds)
+ * (CFS  default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
  */
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_latency			= 12800000ULL;
+static unsigned int normalized_sysctl_sched_latency	= 12800000ULL;
+#else // CONFIG_SCHED_BORE
 unsigned int sysctl_sched_latency			= 6000000ULL;
 static unsigned int normalized_sysctl_sched_latency	= 6000000ULL;
+#endif // CONFIG_SCHED_BORE
 
 /*
  * The initial- and re-scaling of tunables is configurable
@@ -80,25 +89,41 @@ static unsigned int normalized_sysctl_sched_latency	= 6000000ULL;
  *   SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
  *   SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
  *
- * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
+ * (BORE default SCHED_TUNABLESCALING_NONE = *1 constant)
+ * (CFS  default SCHED_TUNABLESCALING_LOG  = *(1+ilog(ncpus))
  */
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
+#else // CONFIG_SCHED_BORE
 unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG;
+#endif // CONFIG_SCHED_BORE
 
 /*
  * Minimal preemption granularity for CPU-bound tasks:
  *
- * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (BORE default: 1.6 msec constant, units: nanoseconds)
+ * (CFS  default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
  */
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_min_granularity			= 1600000ULL;
+static unsigned int normalized_sysctl_sched_min_granularity	= 1600000ULL;
+#else // CONFIG_SCHED_BORE
 unsigned int sysctl_sched_min_granularity			= 750000ULL;
 static unsigned int normalized_sysctl_sched_min_granularity	= 750000ULL;
+#endif // CONFIG_SCHED_BORE
 
 /*
  * Minimal preemption granularity for CPU-bound SCHED_IDLE tasks.
  * Applies only when SCHED_IDLE tasks compete with normal tasks.
  *
- * (default: 0.75 msec)
+ * (BORE default: 1.6 msec constant)
+ * (CFS  default: 0.75 msec)
  */
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_idle_min_granularity			= 1600000ULL;
+#else // CONFIG_SCHED_BORE
 unsigned int sysctl_sched_idle_min_granularity			= 750000ULL;
+#endif // CONFIG_SCHED_BORE
 
 /*
  * This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity
@@ -118,13 +143,29 @@ unsigned int sysctl_sched_child_runs_first __read_mostly;
  * and reduces their over-scheduling. Synchronous workloads will still
  * have immediate wakeup/sleep latencies.
  *
- * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (BORE default: 4.8 msec constant, units: nanoseconds)
+ * (CFS  default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
  */
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_wakeup_granularity			= 4800000UL;
+static unsigned int normalized_sysctl_sched_wakeup_granularity	= 4800000UL;
+#else // CONFIG_SCHED_BORE
 unsigned int sysctl_sched_wakeup_granularity			= 1000000UL;
 static unsigned int normalized_sysctl_sched_wakeup_granularity	= 1000000UL;
+#endif // CONFIG_SCHED_BORE
 
 const_debug unsigned int sysctl_sched_migration_cost	= 500000UL;
 
+#ifdef CONFIG_SCHED_BORE
+unsigned int __read_mostly sched_bore                = 1;
+unsigned int __read_mostly sched_burst_penalty_scale = 1256;
+unsigned int __read_mostly sched_burst_granularity   = 12;
+unsigned int __read_mostly sched_burst_smoothness    = 1;
+static int three          = 3;
+static int sixty_four     = 64;
+static int maxval_12_bits = 4095;
+#endif // CONFIG_SCHED_BORE
+
 int sched_thermal_decay_shift;
 static int __init setup_sched_thermal_decay_shift(char *str)
 {
@@ -179,6 +220,44 @@ static unsigned int sysctl_sched_cfs_bandwidth_slice		= 5000UL;
 
 #ifdef CONFIG_SYSCTL
 static struct ctl_table sched_fair_sysctls[] = {
+#ifdef CONFIG_SCHED_BORE
+	{
+		.procname	= "sched_bore",
+		.data		= &sched_bore,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &three,
+	},
+	{
+		.procname	= "sched_burst_penalty_scale",
+		.data		= &sched_burst_penalty_scale,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &maxval_12_bits,
+	},
+	{
+		.procname	= "sched_burst_granularity",
+		.data		= &sched_burst_granularity,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &sixty_four,
+	},
+	{
+		.procname	= "sched_burst_smoothness",
+		.data		= &sched_burst_smoothness,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &three,
+	},
+#endif // CONFIG_SCHED_BORE
 	{
 		.procname       = "sched_child_runs_first",
 		.data           = &sysctl_sched_child_runs_first,
@@ -879,6 +958,36 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq)
 }
 #endif /* CONFIG_SMP */
 
+#ifdef CONFIG_SCHED_BORE
+static inline void update_burst_score(struct sched_entity *se) {
+	u64 burst_count;
+	u32 msb, bcnt_prec10;
+
+	burst_count = max(se->burst_time, se->prev_burst_time) >> sched_burst_granularity;
+	msb = fls64(burst_count);
+	bcnt_prec10 = (msb << 10) | (burst_count << ((65 - msb) & 0x3F) >> 54);
+	se->burst_score = min(bcnt_prec10 * sched_burst_penalty_scale >> 20, (u32)39);
+}
+
+static u64 burst_scale(u64 delta, struct sched_entity *se) {
+	return mul_u64_u32_shr(delta, sched_prio_to_wmult[se->burst_score], 22);
+}
+
+static u64 calc_delta_fair_bscale(u64 delta, struct sched_entity *se) {
+	return burst_scale(calc_delta_fair(delta, se), se);
+}
+
+static inline u64 binary_smooth(u64 old, u64 new, unsigned int smoothness) {
+	return (new + old * ((1 << smoothness) - 1)) >> smoothness;
+}
+
+static inline void reset_burst(struct sched_entity *se) {
+	se->prev_burst_time = binary_smooth(
+		se->prev_burst_time, se->burst_time, sched_burst_smoothness);
+	se->burst_time = 0;
+}
+#endif // CONFIG_SCHED_BORE
+
 /*
  * Update the current task's runtime statistics.
  */
@@ -908,6 +1017,13 @@ 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_score(curr);
+	if (sched_bore & 1)
+		curr->vruntime += calc_delta_fair_bscale(delta_exec, curr);
+	else
+#endif // CONFIG_SCHED_BORE
 	curr->vruntime += calc_delta_fair(delta_exec, curr);
 	update_min_vruntime(cfs_rq);
 
@@ -4641,6 +4757,11 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	se->prev_sum_exec_runtime = se->sum_exec_runtime;
 }
 
+#ifdef CONFIG_SCHED_BORE
+static int
+wakeup_preempt_entity_bscale(struct sched_entity *curr,
+                             struct sched_entity *se, bool do_scale);
+#endif // CONFIG_SCHED_BORE
 static int
 wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
 
@@ -4685,7 +4806,13 @@ pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 			se = second;
 	}
 
-	if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1) {
+#ifdef CONFIG_SCHED_BORE
+	if (cfs_rq->next && wakeup_preempt_entity_bscale(
+		                  cfs_rq->next, left, sched_bore & 2) < 1)
+#else // CONFIG_SCHED_BORE
+	if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
+#endif // CONFIG_SCHED_BORE
+	{
 		/*
 		 * Someone really wants this to run. If it's not unfair, run it.
 		 */
@@ -5831,6 +5958,9 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 	util_est_dequeue(&rq->cfs, p);
 
 	for_each_sched_entity(se) {
+#ifdef CONFIG_SCHED_BORE
+		if (task_sleep) reset_burst(se);
+#endif // CONFIG_SCHED_BORE
 		cfs_rq = cfs_rq_of(se);
 		dequeue_entity(cfs_rq, se, flags);
 
@@ -7182,7 +7312,12 @@ static unsigned long wakeup_gran(struct sched_entity *se)
  *
  */
 static int
+#ifdef CONFIG_SCHED_BORE
+wakeup_preempt_entity_bscale(struct sched_entity *curr,
+                             struct sched_entity *se, bool do_scale)
+#else // CONFIG_SCHED_BORE
 wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
+#endif // CONFIG_SCHED_BORE
 {
 	s64 gran, vdiff = curr->vruntime - se->vruntime;
 
@@ -7190,11 +7325,20 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
 		return -1;
 
 	gran = wakeup_gran(se);
+#ifdef CONFIG_SCHED_BORE
+	if (do_scale) gran = burst_scale(gran, se);
+#endif // CONFIG_SCHED_BORE
 	if (vdiff > gran)
 		return 1;
 
 	return 0;
 }
+#ifdef CONFIG_SCHED_BORE
+static int wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
+{
+	return wakeup_preempt_entity_bscale(curr, se, false);
+}
+#endif // CONFIG_SCHED_BORE
 
 static void set_last_buddy(struct sched_entity *se)
 {
@@ -7294,7 +7438,12 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 		return;
 
 	update_curr(cfs_rq_of(se));
-	if (wakeup_preempt_entity(se, pse) == 1) {
+#ifdef CONFIG_SCHED_BORE
+	if (wakeup_preempt_entity_bscale(se, pse, sched_bore & 2) == 1)
+#else // CONFIG_SCHED_BORE
+	if (wakeup_preempt_entity(se, pse) == 1)
+#endif // CONFIG_SCHED_BORE
+	{
 		/*
 		 * Bias pick_next to pick the sched entity that is
 		 * triggering this preemption.
@@ -7530,6 +7679,9 @@ static void yield_task_fair(struct rq *rq)
 	struct task_struct *curr = rq->curr;
 	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
 	struct sched_entity *se = &curr->se;
+#ifdef CONFIG_SCHED_BORE
+	reset_burst(se);
+#endif // CONFIG_SCHED_BORE
 
 	/*
 	 * Are we the only task in the tree?
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index ee7f23c76..0f2396e52 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -4,7 +4,11 @@
  * them to run sooner, but does not allow tons of sleepers to
  * rip the spread apart.
  */
+#ifdef CONFIG_SCHED_BORE
+SCHED_FEAT(GENTLE_FAIR_SLEEPERS, false)
+#else // CONFIG_SCHED_BORE
 SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true)
+#endif // CONFIG_SCHED_BORE
 
 /*
  * Place new tasks ahead so that they do not starve already running
-- 
2.25.1