[patch] updated BORE patch - 3.5.2

0001-linux6.6.y-bore3.5.2.patch (text/plain), 17.68 KB, created by deim on 2023-11-22 07:21:05 UTC

From bd0849e34ed79a9344717cc372206530812de189 Mon Sep 17 00:00:00 2001
From: Masahito S <[e-mail]>
Date: Tue, 21 Nov 2023 07:34:36 +0900
Subject: [PATCH] linux6.6.y-bore3.5.2

---
 include/linux/sched.h   |  10 ++
 init/Kconfig            |  19 ++++
 kernel/sched/core.c     | 128 ++++++++++++++++++++++++++
 kernel/sched/debug.c    |   3 +
 kernel/sched/fair.c     | 199 +++++++++++++++++++++++++++++++++++++---
 kernel/sched/features.h |   4 +
 6 files changed, 350 insertions(+), 13 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 77f01ac385..01f2839adf 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -559,6 +559,16 @@ struct sched_entity {
 	u64				sum_exec_runtime;
 	u64				prev_sum_exec_runtime;
 	u64				vruntime;
+#ifdef CONFIG_SCHED_BORE
+	u64				burst_time;
+	u8				prev_burst_penalty;
+	u8				curr_burst_penalty;
+	u8				burst_penalty;
+	u8				slice_score;
+	u8				child_burst;
+	u16				child_burst_cnt;
+	u64				child_burst_last_cached;
+#endif // CONFIG_SCHED_BORE
 	s64				vlag;
 	u64				slice;
 
diff --git a/init/Kconfig b/init/Kconfig
index 9dee4c1003..49d343e97b 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1278,6 +1278,25 @@ 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.
+
+	  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 802551e000..6e15b5be88 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4484,6 +4484,123 @@ int wake_up_state(struct task_struct *p, unsigned int state)
 	return try_to_wake_up(p, state, 0);
 }
 
+#ifdef CONFIG_SCHED_BORE
+extern bool sched_bore;
+extern u8   sched_burst_fork_atavistic;
+extern uint sched_burst_cache_lifetime;
+
+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.slice_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.slice_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 child_burst_cache_expired(struct task_struct *p, u64 now) {
+	return (p->se.child_burst_last_cached + sched_burst_cache_lifetime < now);
+}
+
+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 void update_child_burst_cache(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 (child->sched_class != &fair_sched_class) continue;
+		cnt++;
+		sum += child->se.burst_penalty;
+	}
+
+	__update_child_burst_cache(p, cnt, sum, now);
+}
+
+static void update_child_burst_cache_atavistic(
+	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 (dec->sched_class != &fair_sched_class) 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_cache_atavistic(dec, now, depth - 1, &cnt, &sum);
+	}
+
+	__update_child_burst_cache(p, cnt, sum, now);
+	*acnt += cnt;
+	*asum += sum;
+}
+
+static void sched_post_fork_bore(struct task_struct *p) {
+	struct sched_entity *se = &p->se;
+	struct task_struct *anc;
+	u64 now;
+	u32 cnt = 0, sum = 0, depth;
+	u8 burst_cache;
+
+	if (likely(sched_bore)) {
+		now = ktime_get_ns();
+		read_lock(&tasklist_lock);
+
+		anc = p->real_parent;
+		depth = sched_burst_fork_atavistic;
+		if (likely(depth)) {
+			while ((anc->real_parent != anc) && (count_child_tasks(anc) == 1))
+				anc = anc->real_parent;
+			if (child_burst_cache_expired(anc, now))
+				update_child_burst_cache_atavistic(
+					anc, now, depth - 1, &cnt, &sum);
+		} else
+			if (child_burst_cache_expired(anc, now))
+				update_child_burst_cache(anc, now);
+
+		burst_cache = anc->se.child_burst;
+
+		read_unlock(&tasklist_lock);
+		se->prev_burst_penalty = max(se->prev_burst_penalty, burst_cache);
+	}
+	se->burst_penalty = se->prev_burst_penalty;
+}
+#endif // CONFIG_SCHED_BORE
+
 /*
  * Perform scheduler related setup for a newly forked process p.
  * p is forked by current.
@@ -4500,6 +4617,9 @@ 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
 	p->se.vlag			= 0;
 	p->se.slice			= sysctl_sched_base_slice;
 	INIT_LIST_HEAD(&p->se.group_node);
@@ -4819,6 +4939,9 @@ 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);
 }
 
@@ -9919,6 +10042,11 @@ void __init sched_init(void)
 	BUG_ON(&dl_sched_class != &stop_sched_class + 1);
 #endif
 
+#ifdef CONFIG_SCHED_BORE
+	sched_init_bore();
+	printk(KERN_INFO "BORE (Burst-Oriented Response Enhancer) CPU Scheduler modification 3.5.2 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 4c3d0d9f3d..e37fdfad1c 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -595,6 +595,9 @@ 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.slice_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 df348aa55d..8f4ffd7525 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) 2021-2023 Masahito Suzuki <[e-mail]>
  */
 #include <linux/energy_model.h>
 #include <linux/mmap_lock.h>
@@ -66,17 +69,28 @@
  *   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)
+ * (EEVDF 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: 3 msec constant, units: nanoseconds)
+ * (EEVDF default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
  */
+#ifdef CONFIG_SCHED_BORE
+unsigned int sysctl_sched_base_slice			= 3000000ULL;
+static unsigned int normalized_sysctl_sched_base_slice	= 3000000ULL;
+#else // CONFIG_SCHED_BORE
 unsigned int sysctl_sched_base_slice			= 750000ULL;
 static unsigned int normalized_sysctl_sched_base_slice	= 750000ULL;
+#endif // CONFIG_SCHED_BORE
 
 /*
  * After fork, child runs first. If set to 0 (default) then
@@ -86,6 +100,68 @@ unsigned int sysctl_sched_child_runs_first __read_mostly;
 
 const_debug unsigned int sysctl_sched_migration_cost	= 500000UL;
 
+#ifdef CONFIG_SCHED_BORE
+bool __read_mostly sched_bore                   = 1;
+bool __read_mostly sched_burst_score_rounding   = 0;
+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;
+static u8   sixty_four     = 64;
+static uint maxval_12_bits = 4095;
+
+#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 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);
+}
+
+static inline void update_slice_score(struct sched_entity *se) {
+	u32 penalty = se->burst_penalty;
+	if (sched_burst_score_rounding) penalty += 0x2U;
+	se->slice_score = penalty >> 2;
+}
+
+static inline u64 scale_slice(u64 delta, struct sched_entity *se) {
+	return mul_u64_u32_shr(delta, sched_prio_to_wmult[se->slice_score], 22);
+}
+
+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;
+}
+#endif // CONFIG_SCHED_BORE
+
 int sched_thermal_decay_shift;
 static int __init setup_sched_thermal_decay_shift(char *str)
 {
@@ -145,6 +221,70 @@ static unsigned int sysctl_numa_balancing_promote_rate_limit = 65536;
 
 #ifdef CONFIG_SYSCTL
 static struct ctl_table sched_fair_sysctls[] = {
+#ifdef CONFIG_SCHED_BORE
+	{
+		.procname	= "sched_bore",
+		.data		= &sched_bore,
+		.maxlen		= sizeof(bool),
+		.mode		= 0644,
+		.proc_handler	= &proc_dobool,
+	},
+	{
+		.procname	= "sched_burst_cache_lifetime",
+		.data		= &sched_burst_cache_lifetime,
+		.maxlen		= sizeof(uint),
+		.mode		= 0644,
+		.proc_handler = proc_douintvec,
+	},
+	{
+		.procname	= "sched_burst_fork_atavistic",
+		.data		= &sched_burst_fork_atavistic,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler	= &proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_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_score_rounding",
+		.data		= &sched_burst_score_rounding,
+		.maxlen		= sizeof(bool),
+		.mode		= 0644,
+		.proc_handler	= &proc_dobool,
+	},
+	{
+		.procname	= "sched_burst_smoothness_long",
+		.data		= &sched_burst_smoothness_long,
+		.maxlen		= sizeof(bool),
+		.mode		= 0644,
+		.proc_handler	= &proc_dobool,
+	},
+	{
+		.procname	= "sched_burst_smoothness_short",
+		.data		= &sched_burst_smoothness_short,
+		.maxlen		= sizeof(bool),
+		.mode		= 0644,
+		.proc_handler	= &proc_dobool,
+	},
+#endif // CONFIG_SCHED_BORE
 	{
 		.procname       = "sched_child_runs_first",
 		.data           = &sysctl_sched_child_runs_first,
@@ -313,6 +453,9 @@ 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);
 
+#ifdef CONFIG_SCHED_BORE
+	if (likely(sched_bore)) delta = scale_slice(delta, se);
+#endif // CONFIG_SCHED_BORE
 	return delta;
 }
 
@@ -668,7 +811,7 @@ void avg_vruntime_update(struct cfs_rq *cfs_rq, s64 delta)
  * Specifically: avg_runtime() + 0 must result in entity_eligible() := true
  * For this to be so, the result of this function must have a left bias.
  */
-u64 avg_vruntime(struct cfs_rq *cfs_rq)
+static u64 avg_key(struct cfs_rq *cfs_rq)
 {
 	struct sched_entity *curr = cfs_rq->curr;
 	s64 avg = cfs_rq->avg_vruntime;
@@ -688,7 +831,11 @@ u64 avg_vruntime(struct cfs_rq *cfs_rq)
 		avg = div_s64(avg, load);
 	}
 
-	return cfs_rq->min_vruntime + avg;
+	return avg;
+}
+
+inline u64 avg_vruntime(struct cfs_rq *cfs_rq) {
+	return cfs_rq->min_vruntime + avg_key(cfs_rq);
 }
 
 /*
@@ -709,13 +856,8 @@ u64 avg_vruntime(struct cfs_rq *cfs_rq)
  */
 static void update_entity_lag(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-	s64 lag, limit;
-
 	SCHED_WARN_ON(!se->on_rq);
-	lag = avg_vruntime(cfs_rq) - se->vruntime;
-
-	limit = calc_delta_fair(max_t(u64, 2*se->slice, TICK_NSEC), se);
-	se->vlag = clamp(lag, -limit, limit);
+	se->vlag = avg_vruntime(cfs_rq) - se->vruntime;
 }
 
 /*
@@ -1031,6 +1173,9 @@ static void update_deadline(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	/*
 	 * EEVDF: vd_i = ve_i + r_i / w_i
 	 */
+#ifdef CONFIG_SCHED_BORE
+	update_slice_score(se);
+#endif // CONFIG_SCHED_BORE
 	se->deadline = se->vruntime + calc_delta_fair(se->slice, se);
 
 	/*
@@ -1173,7 +1318,11 @@ static void update_curr(struct cfs_rq *cfs_rq)
 	curr->sum_exec_runtime += delta_exec;
 	schedstat_add(cfs_rq->exec_clock, delta_exec);
 
-	curr->vruntime += calc_delta_fair(delta_exec, curr);
+#ifdef CONFIG_SCHED_BORE
+	curr->burst_time += delta_exec;
+	update_burst_penalty(curr);
+#endif // CONFIG_SCHED_BORE
+	curr->vruntime += max(1ULL, calc_delta_fair(delta_exec, curr));
 	update_deadline(cfs_rq, curr);
 	update_min_vruntime(cfs_rq);
 
@@ -4970,6 +5119,16 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {}
 
 #endif /* CONFIG_SMP */
 
+static inline s64 calc_placement_lag(struct sched_entity *se) {
+	u64 slice = se->slice;
+#ifdef CONFIG_SCHED_BORE
+	if (unlikely(!sched_bore))
+#endif // CONFIG_SCHED_BORE
+	slice *= 2;
+	s64 limit = calc_delta_fair(max_t(u64, slice, TICK_NSEC), se);
+	return clamp(se->vlag, -limit, limit);
+}
+
 static void
 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
@@ -4977,6 +5136,9 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	s64 lag = 0;
 
 	se->slice = sysctl_sched_base_slice;
+#ifdef CONFIG_SCHED_BORE
+	update_slice_score(se);
+#endif // CONFIG_SCHED_BORE
 	vslice = calc_delta_fair(se->slice, se);
 
 	/*
@@ -4991,7 +5153,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 		struct sched_entity *curr = cfs_rq->curr;
 		unsigned long load;
 
-		lag = se->vlag;
+		lag = calc_placement_lag(se);
 
 		/*
 		 * If we want to place a task and preserve lag, we have to
@@ -6611,6 +6773,9 @@ 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) restart_burst(se);
+#endif // CONFIG_SCHED_BORE
 		cfs_rq = cfs_rq_of(se);
 		dequeue_entity(cfs_rq, se, flags);
 
@@ -8341,8 +8506,12 @@ static void yield_task_fair(struct rq *rq)
 	/*
 	 * Are we the only task in the tree?
 	 */
-	if (unlikely(rq->nr_running == 1))
+	if (unlikely(rq->nr_running == 1)) {
+#ifdef CONFIG_SCHED_BORE
+		restart_burst(se);
+#endif // CONFIG_SCHED_BORE
 		return;
+	}
 
 	clear_buddies(cfs_rq, se);
 
@@ -8351,6 +8520,10 @@ static void yield_task_fair(struct rq *rq)
 	 * Update run-time statistics of the 'current'.
 	 */
 	update_curr(cfs_rq);
+#ifdef CONFIG_SCHED_BORE
+	restart_burst(se);
+	update_slice_score(se);
+#endif // CONFIG_SCHED_BORE
 	/*
 	 * Tell update_rq_clock() that we've just updated,
 	 * so we don't do microscopic update in schedule()
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index f770168230..a2e09c04f3 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -6,7 +6,11 @@
  */
 SCHED_FEAT(PLACE_LAG, true)
 SCHED_FEAT(PLACE_DEADLINE_INITIAL, true)
+#ifdef CONFIG_SCHED_BORE
+SCHED_FEAT(RUN_TO_PARITY, false)
+#else // CONFIG_SCHED_BORE
 SCHED_FEAT(RUN_TO_PARITY, true)
+#endif // CONFIG_SCHED_BORE
 
 /*
  * Prefer to schedule the task we woke last (assuming it failed
-- 
2.25.1